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GeoBaikal 2018
- Conference date: August 11-17, 2018
- Location: Irkutsk, Russia
- Published: 11 August 2018
1 - 100 of 114 results
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Assessing Method for the Rocks Wettability by Comparing X-ray Tomograms of a Dry and Contrast Solution Saturate Salvage of Core
Authors S. Galkin, Yu. Kolychev and S. CherepanovSummaryThe possibility of direct evaluation of the rocks wettability by X-ray tomography method. The method is based on the comparison of the tomograms in the dry and saturated state, which allows you to visually assess the degree of impregnation of the core. As the saturating agent, an aqueous solution of NaI was used, the addition of which in water does not change the filtration properties of the fluid, increasing its X-ray density. For hydrophilic samples, complete impregnation of the samples is established, for hydrophobic samples there is no impregnation in the central part. As a result, the types of rocks are distinguished by the degree of wettability: hydrophilic, with average signs of hydrophobicity, with strong hydrophobicity characteristics, absolutely hydrophobic.
For the samples studied, the reliability of the wettability determinations by the Tulbovich method is established, which overestimates the hydrophobicity of the rocks. To monitor the results of tomography, a microscopic analysis of the sections was performed, showing an increased content of organic matter for hydrophobic samples.
In the studied core collection, the results of the wettability evaluation by tomography are in good agreement with the well electrometry data. Samples with an absolutely hydrophobic cut type are characterized by lateral logging resistances of more than 1000 Ohm · m. Samples with signs of hydrophobicity are encountered in intervals with resistances in the range from 120 to 800 Ohm · m. For hydrophilic samples, much lower resistances of less than 100 Ohm · m are characteristic. The relationship between wettability and the conductivity of rocks is of great practical importance, since, when confirmed on a larger volume, the core in the long term allows, by the method of lateral logging, to establish the zonality of the types of rock wetability.
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Well Placement in Carbonates. Success Brought by Multilayer Bed Boundary Detection Technology
Authors S. Lebedev, V. Sayfitdinova, S. Kochneva, V. Permyakov and V. BaryakhSummaryIn the Volga-Ural region, a significant part of the horizontal drilling is carried out on the carbonate formations. Wells with horizontal sections of 300–400 m are drilled on Bashkirian, Tournaisian and Famennian deposits. In addition to maintain the horizontal section within the reservoir, depending on the formation and the field, the task for vertical coverage of the formation is also set. The purpose of this approach is to maximize coverage of the tight and porous intervals vertically, as well as maximize the zone of reservoir drainage. To perform these tasks, understanding the structure boundaries at a distance from the well is critical and is ensured by Multilayer Bed Boundary Detection Technology.
Standard electromagnetic logging of propagation or induction resistivity in highly resistive interbedded formations such as carbonate deposits can to some extent distort the real resistivity values of reservoir, underestimating the values in tight intervals, which usually have very high resistivity.
Nevertheless, the Multilayer Bed Boundary Detection Technology has been successfully used during the well placement in the carbonate sediments of the Volga-Ural region, it allowed mapping the boundaries in conditions of high formation resistivity and low resistivity contrasts between the interbeds.
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Prospects of the Oil and Gas Content of the Vendian Bohan Horizon Within One of the Fields in the South of the Siberian Platform
Authors O.A. Kolycheva, I.A. Farishova and A.D. PletnevaSummaryFor a long time, the sediments of the Bohansk horizon in the south of the Siberian Platform were considered to be unprospective, but with the discovery of industrial deposits at the Chikanskoye gas-condensate field, which is a satellite of the Kovykta field, interest in them has increased. The autor has analyzed the main structural features of prospective terrigenous deposits of the Bohan horizon in the Kovykta field, presents a comprehensive analysis of seismic materials (inversion transformations, dynamic and paleomorphological), which resulted in the heterogeneity of the structure of the target horizon, and also mapped out a prospective area with signs of gas saturation
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Stratigraphic Pinch-out Zones in Riphean Deposits As Promising Exploration Targets for Expanding Gazprom’s Mineral Resources Base in the Central and Western Parts of the Siberian Platform
Authors O.A. Smirnov, A.V. Lukashov, A.S. Nedosedkin and S.A. MoiseevSummaryAt present, Riphean deposits represent one of thepromising exploration targets, which are expected toensure sizeable reserves additions to meet throughput capacitiesof the ESPO oil pipeline and the Power of Siberia gas pipeline. Using three regional seismic profiles Batolit,Kezhma - Patom trough, Svetlaya - Khoshonskaya wells, we examined the mode of occurrence of Riphean deposits inthe zones of their pinch-out. It was shown that, by analogy with the Yurubchenskoe and Kuyumbinskoe fields,the subcrop of the Riphean carbonate deposits beneath the erosional surface may have been favorable forthe deposition of good quality reservoir rocks. The intra-Riphean deposits were shown to have high oil andgas potential. At the present stage of investigation, the priority areas have been delineated for inclusion inGazprom’s exploration and licensing program forthe near and medium term.
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Seismic Wave Tracking and Coherence Estimation Are Two Sides of the One Task
Authors D.Y. Stepanov and R.M. SadykovSummaryIn the seismic wave fields terminology there are two fundamental concepts: wave regularity and spatial coherence. Although these concepts are contiguous, the term regularity is encountered in solving many problems, including the problem of detection (correlation, picking) of seismic waves. Coherence is encountered only in the task of identifying zones of tectonic deformations and fracture zones. Literary sources known to the author consider these problems separately, and the existing algorithms solve them independently.
The report shows that these problems can be solved within the single approach, using the seismic wave field statistical model and analysis of the directional summing results. This approach is an attempt to maximally formalize and automate the problems solution. As a result, the process of coherence cubes calculating does not require the involvement of piking results and can be carried out over the entire volume of initial data. The report presents the results of using the developed algorithms in the interpretation of VSP, 2D and 3D CDP of a number of oil and gas fields in Western Siberia region.
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Restoration and Study of Features of Geological Structure by Modern Methods of Integrated Seismic Processing and Interpretation, on the Example of the Nep Arch, the Nep-botuoba Antecline
Authors V. Shegay, A. Belemets, A. Rozhkova and F. ZeleznyakSummaryThe results of the research allowed to significantly clarify the seismogeological model of the area in comparison with the data of previous years. In the framework of modern works it was possible to obtain a seismic image of the geological environment with the restored position reflecting the boundaries of the studied section due to in-depth study of the features of the geological structure of the area and more correct input of static corrections. Subsequently, the correctness of the specified structural plans was confirmed by drilling. This allows us to clarify the structural and tectonic model of the site and for the first time to make an assumption about the presence of tectonic shift within the work area. It can confined to the junction zone of the NEP-botuoba antecline and Predpatomsky regional trough. The sedimentation model of the target reservoirs was developed for the first time on the basis of the latest data, which allowed to clarify the areas of reservoir development. In comparison with the data of 2012, the latest results made it possible to clarify the hydrocarbon potential of the studied area and reduce the risks during further exploration.
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Integrated Geophysical Investigations at the Khaya Khudag Ritual Complex in Eastern Part of Mongolia
Authors T. Khuut, O. Tserendorj, B. Dashdondog, B. Khuut and B. KhuutSummaryMongolian territory is rich in history and man-made heritage. Hundreds of monuments to testify were left in the vast expanse from the Altai Mountains to steppe eastern Mongolia. In nowadays, non-destructive integrated geophysical prospecting methods have been increasingly used for the investigation of archaeological sites in Mongolian territory. This paper describes the results of integrated geophysical investigation based ground penetrating radar and magnetic surveys in the ritual complex of Khaya Khudag area in Khentii province. The correlation of these non-invasive methods acquires high resolution images of the subsurface to decrease the destruction, time and cost of archaeological excavations. The aim of this work was the recognition, location and mapping of buried ritual complex structures by integrated geophysical survey. The geophysical survey includes the utilization of magnetic and GPR. These techniques are described as fast data acquisition rate, high resolution, non-destructive and cost-effective methods. The present survey was performed through these steps, first a magnetic prospecting was carried out followed by GPR survey. When the GPR profiles were compared with the magnetic data along the same paths there were good coincidence between the positives and negatives in both cases.
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Geostatistic Recognition of Genetically Distinct Shale Facies in the Ordos Basin, North China
By S. LinSummaryIn the Chang 7 section of upper Triassic in the Ordos Basin, hierarchical cluster analysis of the 17 selected parameters identifies 3 genetically distinct shale facies. The results of this study demonstrate the power of combined sedimentology, Geochemistry, Mineralogy and Organic Petrology analysis to improve understanding of variations in shales within a single source rock. Hierarchical cluster analysis allowed the definitive classification of 113 shale samples from the study area. The resulting facies were used as a training set to construct a geostatistic decision tree that can be used to assign (1) genetic affinities and (2) a level of confidence in the classification for any additional shale samples that become available.
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The Application of the “Double Kriging” Method in the Construction of Volumetric Petrophysical Models
Authors V. Shestakov, M.M. Amani, D. Stepanov and G. SysolyatinaSummaryThe constructing of volumetric petrophysical models is in demand for the deposits exploitation and wells drilling tasks. This is due to the fact that petrophysical parameters, such as porosity or permeability, storing important information about porous reservoirs presence or absence, the migration of fluids in the geological environment, and so on. Initially, petrophysical parameters are measured using well logging and core analyses methods, which is why they are known only in borehole or around them. The interpolation of such a limited data set within a three-dimensional region can be carried out using various stochastic and interpolation methods: deterministic interpolators (linear, spline, Newton’s formulas, etc.), sequential Gauss simulation, direct conversion of seismic attributes into GWL parameters, geostatistics, neural networks etc. Recently, the last two methods have being developed most intense, since they are based on the joint use of seismic and GWL data and allow obtaining statistically optimal results. In this article, a new petrophysical parameter predicting method that using two statistical models is presented. The advantages and disadvantages of this method are discussed. Approbation results relying on real materials from the fields of Western Siberia are presented and discussed.
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Reservoir Simulation for the Stable Injection of CO2 Into Saline Aquifer
More LessSummaryRecently, studies on greenhouse gases capture and storage have been actively carried out and CO2 storage project is going on in South Korea. The purpose of this study is to analyze the pressure changes caused by CO2 injection in order to prevent the fault reactivation caused by excessive injection during the storage of CO2 in a saline aquifer and to analyze the co2 migration distance. To ensure the safety, it is essential to analyze the CO2 leakage through the fault. Therefore, the possibility of leakage was assessed based on the maximum allowable pressure of cap rock and the fault reopening pressure. With the analysis of the pressure increase and CO2 migration distance, the proper daily injection rate and maximum storage volume to minimize the possibility of leakage.
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The Innovation Technology Based on an Integral Spectral-velocity Forecast of Reservoir Properties Types of Geological Section and Filtration-capacitive Properties of Reservoirs in Borehole Area
Authors E. Kopilevich, N. Surova, L. Levchuk and G. KuznetsovSummaryThe report focuses on the innovation technology based on an integral spectral-velocity forecast (ISVF) of reservoir properties types of geological section and filtration-capacitive properties of reservoirs in borehole area. The physical basis of technology, it’s description and flowchart are also introduced there. The application of ISVF technology provides an opportunity to complete the forecast of types of geological section and filtrationcapacitive properties of reservoirs (such as rate of porosity, permeability, effective thickness, specific capacity and hydroconductivity) in the form of prediction maps and 3D cubes. Nowadays, the technology has been tested and used in various geological conditions during carrying out regional and prospecting and exploration seismic works.
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Geology and Tectonics of the Olkhon Geodynamic Site (Western Baikal Region)
Authors D.P. Gladkochub, V.S. Fedorovsky and Z.L. MotovaSummaryThis post-conference trip takes the participants to Minor Sea of Lake Baikal, central western Baikal area to give them an idea of local geology and history of Lake Baikal, to show well-shaped folds, faults, and traces of glacial and karst activity.
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Justification of 3d-seismic Data Azimuthal Attribute Analysis Application in Geomechanical Modeling
Authors R.N. Sitdikov and A.V. StepanovSummaryPetroleum geomechanical modeling is a process of determining mechanical properties of a rock and its reactions to impacts during development of an oil field. When constructing a geomechanical model of an object, the initial stage is building of a structural model of the geological environment. One of the main elements of this model is a skeleton of fault tectonics. Ordered fracturing as an element of the skeleton is manifested itself by the anisotropic properties of seismic wave fields. In this article, we will consider the possibilities of studying the anisotropy of the geological environment in connection with the construction of a geomechanical model based on using amplitude information of reflected waves. The feasibility study of using azimuth attributive analysis of seismic data at selected research facilities located in the southeast of Tatarstan will be performed. In these studies, as a tool, we used a full wave modeling Tesseral software.
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Cost-effective Time Lapse Seismic Based on Direct Transmitted P-waves for Monitoring Sagd Heavy Oil Production
Authors M. Gareev, M. Amerkhanov, M. Lyabipov, A. Stepanov, R. Sitdikov and A. LomonosovSummaryThe purpose of seismic experiments was to develop a cost-effective seismic monitoring technology for a shallow heavy oil reservoir driven by SAGD. A permanent buried seismic monitoring system was deployed at one of oil sand bitumen reservoir within Cheremshan-Barstrick group of heavy oil fields, Tatarstan (Russia). It consisted of a network of measuring wells. A heat-resistant geophone was placed in each well at a depth of several meters below the base of oil sands reservoir. Field experiment included base and two monitor surveys performed during the year. To control seasonal variations of near surface elastic properties of formation a surface low channel geophone array centered relative to the wellhead of the measuring well was used upon survey. A quantitative interpretation based on time lapse direct transmitted P-wave inversion was used to determine temperature changes in reservoir conditions caused by steam injection and production. To validate seismic results, maps of ray velocity difference between base and first monitoring as well as first and second monitoring surveys were compared with temperature logs of wells-producers. They showed good correlation and had no contradictions. We concluded that the developed seismic acquisition and the workflow have sufficient sensitivity for mapping changes in reservoir conditions.
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Learning From Ten Years of Applying Framework Project Management for Safety in BP Geophysical Data Acquisition Projects
Authors J. Naranjo, G. Schurter and N. CaveSummaryFollowing a fatal injury of one crew member on a land seismic acquisition crew in North Africa in 2007, BP implemented a Global Framework Project Management tool for operated surveys. Today, we can evaluate the effectiveness of the implementation of BP’s Management of Geophysical Operations (MoGO) following ten years of operations under the framework.
Seismic acquisition surveys are inherently dangerous. Often, crews are comprised of large numbers of people (10s to 100s), that are required to work for months, even years, in harsh environments. Given these conditions, this activity is typically nominated “high risk” to the oil and gas operating companies. The MoGO framework has helped BP to approach each project and contractor in a disciplined, structured manner to safely plan and execute geophysical data acquisition projects. This approach has helped BP to be consistent internally and externally, for all surveys and contractors. In this paper, we provide commentary on the project phases and examples that have been shaped by environmental and safety decisions in specific phases throughout the MoGO. In some cases, projects were modified, improved or abandoned based on varying criteria where the framework process aided BP to improve safe operations in geophysical data acquisition.
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Exploration Works Planning Using Value of Information Concept in Geological Uncertainties and Project Limitations
Authors P.Ya. Mostovoy, R.A. Oshamrin, V.S. Rukavishnikov and A.M. VashevnikSummaryThe S field development plan is focused on the Jeribe/Upper Dhiban reservoir interval. There is significant uncertainty in estimate of stock-tank oil initially in place (STOIIP) and recoverable resources due to the absence of a defined oil-water contact (OWC) in the wells drilled to date H-1 and S-1.
The field is considered to be developed by six wells. However because of uncertainty in reserves field development balances the need for immediate production with the need to assess the most likely reserve size as quickly as possible in order to optimize the full field facilities.
The approach to optimal drilling sequence finding in geological uncertainties and limiting conditions is offered in the research - evidence from S oil field. The suggested approach is used to recommend optimal drilling sequence of planed wells to reduce economic risks and obtain the highest NPV of S development project. The optimal drilling sequence was found using value of information approach leading to the highest project expected monetary value from more than 120 possible drilling sequences.
The dynamic development strategy that reduces uncertainties and economic risks by VOI approach - drilling risky well in the first two years of production and depending on the outcome realize facility optimization and further drilling was recommended.
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Initial Data Preparation for Naturally Fractured-cavernous Carbonate Reservoirs of Osinskiy Horizon Geological Modelling
Authors O.A. Timakov and E.A. RomashevSummaryA significant part of hydrocarbon resources of Leno-Tungussian oil-and-gas province is confined with carbonate deposits of Osinskiy horizon (O–1 formation, Billirskaya suite), represented by ancient Paleozoic limestones and dolomites, most of which have mixed cavernous-porous and fractured-cavernous type. One of the main difficulties in developing geological models of such complex reservoirs is the selection of modelling algorithms that allow to reproduce the high heterogeneity of their filtration-capacitive properties associated with the impact of post-sedimentation processes and the non-linear geometry of the void space.
In this paper, we present the results of the collection, processing and analysis of primary geological and geophysical data that precedes the stage of full-scale geological and hydrodynamic modeling. The main features of the considered object, located in the central part of Nepskiy arch (Nepsko-Botuobinskiy region), are a large size of modeling area and a number of production wells, which makes it difficult to provide the required amount of special researches. An important factor is the significant loss of accuracy during geological model upscaling process and the necessity to maintain adequate duration of hydrodynamic calculations. Thus, a certain compromise is required between the detail level, the size of the model and time costs of its creation.
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Shallow Seismic Reflection Survey at Mogod Active Fault to Investigate Subsurface Structures
Authors N. Erdenetsogt and B. GanboldSummaryThis study tried to determine shallow structures of Mogod fault by using shallow seismic reflection survey , then compared its result with geological information.
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Geological and Geophysical Data Integration in the Geological Model of V13 Formation of Chona Field on the Assessment Stage of Project
Authors P.Ya. Mostovoy, R.R. Husnitdinov, V.S. Vorobev and P.P. EmelyanovSummaryThe aim of the investigation is geological and geophysical data integration in a seismic-geological model of a complex heterogeneous reservoir,V13 formation, which is considered as a base for exploration works planning and successful further field appraisal.
By means of using regional data, deep geological analysis, technological projects results, unconventional approaches to geophysical data processing and interpretation taking into account peculiarities of field geology and geological modelling using geostatistical inversion the review of geology aspects V13 formation reservoir on Chona field was made and planning exploration works were reconsidered.
Two pilots of appraisal well were drilled to verify a prediction according to the final seismic-geological model. The aims of pilots were two predicted zones with good and bad reservoir quality. According to conducted cameral works and drilling results analysis it may be concluded that high detailed seismic-geological model gives a qualitative base for decision making about explorations works in conditions of complex reservoir and major explorations projects that corresponds with high economics risks.
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Where Do We Stand With Wireless Acquisition Systems Capabilities?
Authors N. Tellier, S. Wilcox, V. Boreiko, A. Abashkin and V. ZaborodkoSummaryLand seismic recording equipment manufacturers consistently evolve their products striving to create the “perfect” registration system which is viewed as power-efficient, cost-effective and reliable solution, able to transmit in real-time mode both the seismic data and the information about its current operational status to ensure the comprehensive quality control. Unlike cabled, technical solutions used in the wireless registration systems today still remain the matter of compromise defined by the method of implementation of the available tecnologies. The presentation includes the comparison of the most important technologies used in different systems, and their impact on the systems' technical features.
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Enhanced Oil Recovery Technologies for the Arctic Region
Authors L.K. Altunina, V.A. Kuvshinov and I.V. KuvshinovSummaryIn the coming decades, the Arctic region of Russia will be the main reserve of the country's oil and gas production industry. For effective development of oil fields in the Arctic, it is necessary to create and scale up scientifically based oil production technologies adapted to the northern conditions. The paper presents new oil recovery technologies developed at the IPC SB RAS, which can be used in the Arctic fields. The technologies with the use of thermotropic inorganic gelforming compositions GALKA® and MEGA, oil-displacing compositions with controlled viscosity and alkalinity of NINKA® and GBK are promising. The compositions have low freezing point, are effective in a wide range of geological and physical conditions and stages of field development.
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Increasing the Efficiency of the Orenburg Oil and Gas Condensate Field Development Through the Introduction of an Intelligent Gas Injection Control System to Optimize the Gaslift Operation of Wells
Authors V.V. Ulyanov, E.A. Kibirev, M.T. Nukhaev, K.V. Rymarenko and V.S. BakSummaryGaslift is widely used in the world practice of oil production. At the moment, one of the realizations of this production method is used at the Orenburg oil and gas condensate field - a gas compressorless method of operating wells. The paper presents the experience of Gazpromneft-Orenburg on the introduction of an intelligent gas injection control system.
The advantage of the compressor-free gas-lift mode of operation is a significant reduction in operating costs. A feature of this method of operation is the need for continuous control of injection into each well. A system with automatic control valves was introduced to automate the injection of gas in the Orenburg oil and gas condensate field, which allowed point-setting of the injection, constantly monitoring and measuring the gas injection for each well.
The implementation of the concept of an smart field allowed Gazpromneft-Orenburg not only to optimize the operation of the gas lift wells, but also to optimize the work in the field as a whole, including:
- the release of the time for personnel to analyze and make decisions by reducing the routine operations;
- optimization of the operators’ work due to remote control of technological objects, wells;
- Reducing the risks of labor and personnel safety in conditions of high hydrogen sulphide content.
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Description of the Geological Structure and Hydrocarbon Potential of the License Area Rusanovsky the Waters of the Kara Sea by 3d Exploration Seismic Data
Authors V.N. Borodkin, A.R. Kurchikov, V.A. Lukashov, O.A. Smirnov and A.V. PogreckijSummaryThe article presents a brief tectonic timing of the research area, oil and gas characteristics with the release of oil and gas complexes (NGK). On the basis of 3D seismic exploration, seismogeological models are presented, perspective objects are identified, the optimal volume of geological exploration is planned.
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Consideration of Near Surface Anomalies at the Time of Depth Migration
Authors A. Burlakov, S. Ilyin, M. Gabova, I. Shamsutdinov, E. Kuchkanov and P. PopovaSummaryThis report will analyze methods of near surface anomalies’ consideration at the time of depth migration. One of the main troubles with obtaining true location of reflection horizons in depth domain is connected with velocity anomalies in the near surface. Therefore, in our report we will investigate near surface model building with support from seismic data engaging extensive wells’ information. Constructed near surface model will be included in generic depth velocity model.
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Complex Solutions in the Field of Industrial Safety in Geological Investigation Works
Authors P. Didenko and A. SukhodolovSummaryThe region of Eastern Siberia is a difficult area for geological investigation works not only from the point of view of Geology and Geophysics, but also from the point of view of industrial safety. This is harsh climatic conditions, often 100% autonomy, the length of the winter road more than 700 km, the lack of market contractors. In order to reduce injuries, “Gazpromneft-Angara” LLC began to deal with issues of industrial safety in 2012.A lot of results were achieved during the period of 2013–2018 which contributed to the formation of complex solutions in the field of industrial safety, namely: the organization of medical services, transport safety, supervision of industrial safety, requirements for residential wagon-house. It should be noted that “Gazpromneft-Angara” LLC impliment part of the issues on its own.
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Analyzing Modern Technologies for Acquiring, Processing and Interpreting Geophysical Data: The Case of the Arctic Shelf Projects
Authors G.A. Zavarzina, D.S. Shapabaeva, V.A. Kosmynin, R.R. Murzin and O.A. ZakharovaSummaryTurning the Arctic offshore projects into reality remains a distant possibility. However, a valid present-day concept is still needed to develop the oil and gas fields discovered so far and implement prospecting and exploration programmes. A particular emphasis is therefore placed on how we can introduce novel approaches to acquiring, processing and interpreting geophysical data to minimize the costs of exploration activity in the offshore Arctic regions.
This paper discusses both conventional G&G approaches and new technologies aimed at harnessing hydrocarbon resources of the Arctic shelf.
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Aero-tem Effective Magnetic Moment Estimation on the Example of Localization of a Kimberlite Object
Authors I. Ivanova, A. Belaya, A. Chernyshev and G.M. TrigubovighSummaryIn this work an estimation of the affection of current decay time duration on TEM curves by means of mathematical modelling is described. Horizontally layered medium with vertical cylindrical inhomogeneity is taken as a geoelectrical model.
Kimberlites in host rocks form zones of increased conductivity, which represent a criterion of identification of search objects and determine advantage of using the methods of electromagnetic prospecting. In particular, TEM is used for solving search and parameterization tasks for kimberlite objects. However, the effectiveness of TEM application directly depends on the selection of a correct measurement technique, including current decay time duration in the source.
The question arises as to how current decay time duration in a source affects the amplitude of the anomaly caused by the local conductive subvertical object and what time ranges of turn-off current decay time duration are acceptable. This article is devoted to the study of this problem by means of mathematical modelling
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Features of Organogenic Buildups in Osinsky Horizon Facial Zones (Siberian Platform)
Authors E.N. Maksimova and K.N. ChertinaSummaryA comparative analysis of the Cambrian organogenic microbial buildups in various facial zones in the territory of the Nepa-Botuoba anteclise (Eastern Siberia) was completed.
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Structure of the Earth’s Crust and Upper Mantle of the North Muysk Segment of the Baikal Rift Zone According to Seismic-gravity Data
Authors V.V Mordvinova, M.A. Khritova, E.Kh. Turutanov, E.A. Kobeleva and M.M. KobelevSummaryThe performed interpretation of seismic-gravimetric data in the North-Muysky area of the Baikal rift zone makes it possible to estimate the thickness, extent and direction of sinking of the sole of large geological bodies of acidic composition and to isolate in the earth’s crust large-amplitude thrusts with a length of hundreds of kilometers.
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Gazprom Neft Company Experience in Specific Probabilistic Approach for Resource Potential Estimation in Different Exploration Maturity Shelf Project
More LessSummaryGazprom neft company has developed the program of resource base enhancement untill 2025 including Russian shelf licenses. Consequently a resource potential estimation for frontier and emerging areas is important task for exploration process.
In this report Gazprom neft probabilistic approach for shelf projects resource estimation is analyzed and exploration maturity influence on assessment is shown.
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A Critical Analysis of the Experience of Using Intelligent Inflow Indicators for the Continuous Monitoring of Horizontal Wells at the Fields in Russia: Including Prirazlomnoye and Yu. Korchagin
Authors I.R. Mukhametshin, M.T. Nukhaev, A.R. Galimzyanov, A.V. Koloda, O.I. Abramenko and A.A. SenkovSummaryOffshore field development is a complex task, an effective solution of which is impossible without conducting a wide range of research. While developing deposits with long horizontal wells, one of the important tasks is to continuously monitor each of the wellbore intervals to select optimal operating conditions and prevent early breakthroughs of water and gas. The paper presents a critical analysis of the experience of using intelligent inflow indicators for the continuous monitoring of horizontal wells in the fields in Russia. This experience allowed not only to solve local operational problems, but also to update the hydrodynamic models. Knowing the intervals of the maximum and minimum inflow, one can determine the zonal productivity and link it with the geology of the reservoir. The following process is used: the permeability of the various intervals is restored, taking into account the well operating conditions and formation pressure . Then, the integral permeability obtained by well test is compared with results from tracers studies. The last stage is the linkage of the obtained per interval permeability with the petrophysical and facies model. This approach is necessary to obtain a single picture of the geological structure of the reservoir, accurate prediction of the operation of the exploited wells.
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The Selection of the Optimal Development System for Heterogeneous Reservoirs With Hard-to-develop Deposits
Authors M.V. Naugolnov, V.Yu. Klimov, S.Sh. Iskhakova and A.A. SednevSummaryThis work is devoted to the aspects of the selection of optimal development systems for the conditions of highly heterogeneous reservoirs with hard-to-recover reserves using the example of the Achimov deposits of Western Siberia. The choice is based on the use of multivariate 3D hydrodynamic modeling on the basis of various implementations of the conceptual geological 3D model. Different well spacing, methods of well completion and operating modes are considered; the development systems that are best for different facies zones of deep-sea sediments are justified
With the use of multivariate modeling, functions linking the type of completion of the well and the need to organize a reservoir pressure maintenance system with permeability and lateral heterogeneity of the formation are obtained. Sensitivity analysis demonstrated the stability of design solutions to variable geological factors and allowed to assess the value of their influence on technological and economic performance indicators. The proposed methodical approach is relevant not only for the Achimov deposits of Western Siberia, but also for any deposits with hard-to-recover reserves, with high degree of variability or poor knowledge.
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Guidelines for Low-altitude Aeromagnetic Surveys (Russian Federal Agency for Subsoil Use, 2018) - the Main Points and the Authors' Comments
Authors A.V. Parshin, V.S. Tsirel and A.K. RzhevskayaSummaryAt present, in the Russian Federation, the normative base for performing magnetic prospecting is the «USSR Magnetic Survey Instruction Manual, 1981». This document played and plays the major role in methodical maintenance and unification of results of magnetic surveys. However, with the technological progress, there are innovations that significantly change the practice of magnetic prospecting. One such innovation is the robotic magnetometric systems based on light highly maneuverable unmanned aerial vehicles (UAVs), which significantly increased the efficiency of magnetic surveys, especially in complex landscape-morphological conditions. The methodic of such variant of the magnetic prospecting can differ substantially from the traditional methodic of ground and aeromagnetic surveys. It is not regulated by the USSR Instruction, 1981, which makes it difficult to use unmanned geological exploration methods in Russia, and determined the need to develop an appropriate normative document. In this regard, in 2018, the Federal Agency for Subsoil Use prepared and approved the “Guidelines for low-altitude aeromagnetic surveys,” which supplement the classical “Instruction .., 1981” and establish the basic requirements for the produce and quality control of magnetic surveys with UAVs. «Guidelines» summarize the current level of practice and the latest achievements of research in the field of unmanned aerogeophysics and technologies providing it. In this paper, the authors of the «Guidelines» discuss its main theses.
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New Role of Thermal Petrophusical Tehcnologies at Exploration, Prospecting and Development of Oil-gas Fields
Authors Yu. Popov, E. Popov, E. Chekhonin, A. Gabova, E. Savelev and A. GoncharovSummaryNew thermal petrophysical technologies, developed in 2014–2018, have been promptly implemented for solution of different problems in exploration, prospecting and development of hydrocarbon fields. During last few years vast measurements of rock thermal properties - thermal conductivity, thermal diffusivity, volumetric heat capacity, thermal anisotropy coefficient, coefficient of linear thermal expansion - have been performed with the new technologies on more than 30 000 core samples from 31 wells drilled in 26 oil-gas fields of heavy oil and unconventional reservoirs. Integration of the new thermophysical technologies with well logging methods and new established correlations of the thermal properties with other rock properties allowed us to improve essentially effectiveness of methods of thermal petrophysics and to extend areas of their applications in oil-gas industry. The developed technology of non- contact non-destructive continuous thermal core logging provides high-resolution recording variations of rock thermal properties with a spatial resolution of ~1 mm and is combined with following measurements of the thermal properties at formation temperatures up to 300 C. The new thermophysical technologies become particularly actual in conditions when significant multi-scale heterogeneity and anisotropy of rocks within many hydrocarbon fields reduce effectiveness of standard petrophysical logging methods due to their restricted spatial resolution.
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Importance of Conceptual Geological Model in Probabilistic Field Assessment
By O.A. PopovaSummaryAppearance of probabilistic geological models has created an impression that one of the oldest and the most common problems of deterministic modelling - failure of initial assessments - is solved. Indeed, probabilistic model considers a large set of possible realizations of the deposit geology, and, in the perfect world, the range of uncertainty should be narrowed with obtaining new data. However, a new well often brings surprises: either it widens the uncertainty interval, or moves it beyond the initial distribution. Repetition of such cases leads to disappointment in probabilistic models. Should not we stop using them? Analysis of successful and unsuccessful probabilistic case studies shows that one of the reasons that can critically affect the results of assessment and the project as a whole is the choice of conceptual geological model for the object. The paper considers the existing views on the idea of conceptual model and suggests an updated interpretation of it. In the context of probabilistic modelling, the creation of a conceptual framework is an integral part of uncertainty analysis and decision making. And the correct consideration of all possible geological concepts makes it possible to reduce the number of “black swans”.
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Distortion of the Reflected Wave Hodograph Using the Floating Reduction Level on the Example of the Eastern Siberia Region
By A.A. PyankovSummaryIn the last period there seems to be considerable interest in the production of 3D surveys in areas of Eastern Siberia. In the process of designing the field work, as a rule, the study of the upper part of the cut is not given due attention. When processing seismic data in areas with highly variable terrain of the observation surface is used not flat, but “floating” level of reduction. The effect of non-horizontal boundaries based on the OGT seismogram leads to overestimated velocity estimates. For the correct analysis of summation rates, it is proposed to calculate and use the local statics for the floating level of processing on each base of the OGT
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Southern Baikal Region as a Model Site for Studying Late Proterozoic Deposition and Oil Generation History
SummaryГеологический семинар будет интересен для специали-стов нефтегазового сектора. Часть маршрута будет про-?ходить на корабле по Байкалу от пос. Листвянка до пос.Большое Голоустное. В этом интервале протяжённостью?60 км по берегам обнажаются породы, которые отража-ют значительную часть земной истории. Вдоль Листвянки?и за ней вскрываются гранитоидные толщи, возраст фраг-ментов которых датируется от 2,8 до 3,4 млрд. лет. Они?прорываются дайками базитов мезо, неопротерозойскогои палеозойского возрастов. За посёлком Большие К оты эти?породы сменяются конгломератовой толщей юры с про-пластками углей, которые прослеживаются на север в Че-?ремховский угольный бассейн и имеют ориентировочныйвозраст 170 млн. лет. Далее к северо-востоку при прибли-?жении к посёлку Большое Голоустное, в пади Кадильнаяогромными столбами встают известняки с определённым?возрастом 580 млн. лет. Самым замечательным в них яв-ляются прекрасно отпрепарированные строматолитовые?постройки – свидетель цианобактериальной (и водоросле-?вой?) жизни в то время. И при приближении к посёлку поберегу озера вскрываются разрез голоустенской свиты не-?опротерозоя и галечно-песчаные отложения морского днаБайкала, образованные в последний миллион лет. По пути?от Большое Голоустное к Иркутску, вдоль рек Голоустнаяи Правая Ушаковка в придорожных обнажениях наблюда-?ются фрагменты разреза неопротерозойских толщ, частькоторых является нефтематеринскими. Судя по данным?бурения, к северу они фациально меняются и выклинива-ются. При приближении к Иркутску разрез наращивается?поздневендскими и нижнекембрийскими отложениями,которые перекрываются песчаниками юры.
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The Sedimentary Structure of the Siberian Platform Cambrian Marginal Basins and the Methodological Causes of Some Tectonic Errors
By S. SukhovSummaryThe integrated multiyear study results of Cambrian sedimentary architectures are presented. They are based on outcrops, well records and seismic-reflection data as well as sedimentation modeling. The analysis allow to reconstruct reef-rimmed carbonate platforms attended by open edge craton basins and explain dipping as progradational stacking pattern with clinoforms, the infilling of the accommodation in contrast to popular tectonic interpretation.
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Differentiation of Petrophysical Properties of Rocks As a Function of Facial Affiliation
Authors I. Sysoev, N. Popov and D. GlushkovSummaryThe present work is dedicated to the study of poroperm and surface properties, determination of relative permeabilities and displacement efficiency on core samples of various sizes, taking into account facial zonality. Based on the research: the differentiation of poroperm and surface properties of core depending on the facial accessory was established; presence of scale effects was established; recommendations on the justification of the displacement efficiency, taking into account the confinement to different facies have been developed.
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Methods and Results of Terrigenous Reservoir Log Interpretation of the Nepsky Arch Central Part, Eastern Siberia
Authors D. Leznin and D. ShabrikovaSummarySiberian craton is one of the most important mineral resourses bases in Russia. However, because of compound geological structures, the area is not explored properly. Even the most examined areas have unresolved geological problems. One of these is the correct prediction of oil-and-gas presence and reservoir quality discrimination of terrigenous deposists in Vendian oil producing play.
This article focuses on development of methodical approach and complex log interpretation algorithms for reservoir quality discrimination, saturation estimation and determination of porosity, shaliness and oil saturation factor in licensed area of the Nepsky arch central part of Nepsko-Botuobinskaya anteclise. In practice, applying of this methodical approach enabled to determine reservoir properties and to increase the accuracy of porosity and permeability estimation from the logs data.
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Complexing of 2D MOGT Seismic Survey and High-precision Gravity Prospecting for Amendment of Static Corrections by the Example of the Severo-nakanovskaya Area
Authors A.V. Shargorodsky and S.V. GachenkoSummaryThe perennial seismic work carried out under the conditions of the salt tectonics of the sedimentary cover, as well as the saturation of its trap intrusions, showed the low efficiency of the traditional methods of wavefield correction, based only on seismic characteristics. The involvement of other geophysical methods, such as electrical prospecting, and magnetic prospecting, with the exception of special cases, did not solve this problem. Similar problems are, in particular, for the areas of the south of the Siberian platform, on the work sites of the Irkutskgeofizika enterprise and other organizations. The application of the presented method of correction the static corrections made it possible to minimize the differentiation of the wave field at the ambiguous sections of the preliminary time profiles
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The Use of the Complex of Electromagnetic Soundings for Study of Electrical Conductivity of Bottom Sediments of the Lake Baikal
Authors M. Shkiria, S. Tereshkin, Yu. Davydenko and M. PetrishchevSummaryThe study of the bottom sediments of the Lake Baikal is part of a wide scientific field devoted to the study of the deep structure of the Baikal rift zone. Studies in this direction have been conducted since the middle of 20th century. The study of the bottom of the Lake Baikal is a rather complicated process, connected with many technical difficulties. In conditions of a deep water body it is very difficult to extract whole samples of bottom sediments for their further analysis. In this connection, the application of remote methods of investigation of the sedimentary stratum, for example, geophysical methods, is an urgent topic.
One of the solutions to this problem is the use of the complex of electromagnetic soundings to study the section of bottom sediments of the Lake Baikal in terms of electrical conductivity. An integrated approach with the use of magnetotelluric sounding technology and the method of electromagnetic soundings and induced polarization makes it possible to perform studies on bottom sediments at depths of the reservoir from 0 to 2 km. It allows to determine the distribution of the electrical conductivity of bottom sediments at depths of up to 5–7 km and the structure of the conductivity of the underlying rocks or their specific resistance.
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On Application of Assisted History Matching to Reliable Production Forecasting
Authors N. Kolesov, E. Kropachev, E. Sechenina, D. Samsonov and A. ChuprovSummaryThis paper presents a workflow with application of assisted history matching tool for updating and improving reservoir models. In this approach the best-matched reservoir model or an ensemble of models is selected for production forecasting. Furthermore, the convergence of the reservoir model is rated by History-Matching Assessment Form proposed by the authors. This allows the user to visualize and control the selection of the most reliable production forecasts. Afterwards, a set of final production forecasts with uncertainty assessment is made based on ensemble of best-matched reservoir models. The proposed workflow was applied to a large producing field in Eastern Siberia. It shows the usability and meets production forecasting challenges. In addition, the method can improve understanding of uncertainty of a target formation to revisit field development strategy. This helps to obtain correct well performance for acceptable history match and production forecast. Up to threefold speed-up is reached as a result of replacement of manually corrected and time-consuming history matching by automated iterations using assisted history matching software. By analogy, it is possible to apply the workflow to development projects where reservoir parameters often tend to have wide variability, particularly those cases that are in lack of formation uncertainty studies.
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Complex of Geophysical Methods for Studying the Geological Structure of the Intrusion of Dolerites (Trapps) at the Srednebotuobinskoye Field
Authors O. Krokhaleva, M. Shapovalov, E. Goguzeva and V. GrinchenkoSummaryThe paper presented the results of the complexation of geophysical methods for studying the geological structure of dolerite intrusions are presented in order to minimize the complications in the construction of wells.
When studying the problem of absorption of the washing liquid, it was concluded that there are zones with different properties. The author has carried out an analysis of historical data, geophysical research and their reinterpretation. The results of application of the high- tech GIS complex in the study of intrusion properties are shown.
Based on the results of the study, a geological concept of the structure of the trap body at the Srednebotuobinskoye oil and gas condensate field was formed.
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Determination of Methods for Revealing a Layer of High Viscosity Oils on the Example of Srednebotuobinskogo Oil and Gas Condensate Field
Authors E. lukyantseva, I. Oparin and A. KobyashevSummaryThe physical properties and composition of oil within the same reservoir do not always remain constant.
Changes in the properties of oil in the deposits depend on many factors: the Genesis of reservoir fluids, reservoir depth, thermobaric regime and other factors.
The viscosity of the oil increases from the dome of the arch to the wings and to the zone of water-oil contact. To zones of water-oil contact viscosity characteristics of reservoir oil increase due to gravitational redistribution of high-molecular components of oil and dispersing them into the transition zone at the boundary of water-oil contact.
Each Deposit has its own set of causes of changes in the properties of oil in the reservoir and at the stage of research development processes they must be studied. The reasons for changes in the properties of oil on the area of the field are very diverse. Geological and structural features of the structure of the Deposit, the presence of formation exits to the surface, chemical, bacteriological, physico-chemical and other processes occurring in the reservoir, directly or indirectly affect the composition and properties of oils.
Knowing the initial distribution of oil properties on the reservoir and the dynamics of changes in the composition and properties of oil extracted from wells, it is possible, for example, to judge the directions of movement of oil in the reservoir, to establish the relationship of oil and injection wells of a multi-reservoir, to assess the productivity of individual.
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Some Results of Complex Nmr-researches of Hihg-viscous Oiles on the Oilfields of Tatarstan
Authors V. Murzakaev, A. Bragin, N. Belousova, V. Skirda, M. Doroginizkij, T. Abdullin and M. AmerchanovSummaryThere are presented results of complex high-resolution researches of wells by the nuclear magnetic resonance tool in strong field and researches of core, that was extracted from the same intervals. There are given some recommendations about application of mobile apparature NMR-Core for fullsize core researches directly on the borehole.
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Water Injection Design: Ink Carbonate Field Example
Authors S. Zimin, D. Burdakov, V. Sibilev, V. Gomulsky and O. TokarevaSummaryThis work reviews an example of water injection planning with respect to Irkutsk Oil Company carbonate reservoir. Pilot water injection, 4D electric survey, reservoir simulation are considered as a methods reducing geological uncertainties. Basic research compilation are basic to establish waterflooding target performance.
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New Productive Objects in the Vendian Sedimentary Complex of the Srednebotuobinsky Field (Siberian Platform)
Authors L.V. Torgashova, N.N. Chikina, V.A. Grinchenko, V.A. Galiaskarov and A.V. YukhnevichSummaryThe authors describe a case study of the Sredneobuobinskoye Field to justify the potential of unexplored oil and gas bearing complexes. Past years of geological exploration program at the Srednebotuobinskoye Field allowed to discover a number of previously unknown oil and gas bearing targets: the basal layer of the Uspunskaya Series, the Arylakhsky Horizon, the productive intervals of the Upper Buyckskaya sub-series. The geology of the identified targets is described. As the hydrocarbon reserves of the main productive layers deplete, they will be replenished from new promising targets.
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Improving the Quality and Reliability of the Seismic Image As a Result of the Detailed Velocity Model Restoration for the Complex Enviroment of the Siberian Platform
Authors D. Tverdokhlebov, A. Kleshnin, E. Kashirina, A. Batischeva, V. Korobkin, A. Chirgun, A. Filichev and S. GolopapaSummaryImproving the quality and reliability of the seismic image in the complex seismic and geological environments of the Siberian Platform is one of the main tasks in performing both seismic acquisitions and data processing. One of the key elements is the construction of a detailed depth velocity model using wide-azimuth 3D seismic data. There are various methods for constructing a velocity model of the medium in the geophysicists arsenal - based on surface, refracted and reflected waves. An integrated approach based on well-logs data can allow the construction of a detailed depth velocity model of the medium that can improve the quality of the seismic image in the time domain by better static corrections and the reliability of prospects focusing through depth migration.
The paper presents fundamentally different algorithms for recovering the velocities of the high-frequency current and a comprehensive approach to the construction of depth velocity model by the example of the area located in the central part of the Nepa-Botuoba anteclise in the Irkutsk region. The results of the production application of SWI, FWI technologies for near surface velocity and the use of nonlinear tomographic refinement of the velocity model with azimuth information taken into account are presented.
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Application of Multilateral Wells at Taas-yuryakh Neftegazodobycha LLC. Perspectives for Fields of Eastern Siberia
Authors A.S. Suturin, A.G. Yanyshev, R.B. Sultanov and V.A. GrinchenkoSummaryThe Srednebotuobinskoye oil and gas condensate field is one of the largest deposits in Eastern Siberia (RF). The structure of this field is characterized by the presence of an extensive gas cap,oil rim and underlying plantar water. Analysis of early production data showed the main difficulties associated with the development of reservoirs with contact reserves - gas-cone formation and early breakthrough of gas to the bottom of producing wells with low oil withdrawals. In this regard, Taas-Yuryakh Neftegazodobycha LLC has been actively developing new technologies for drilling and the exploitation of this large and complex field. This involves the construction of particularly long horizontal multiple laterls and operation of wells with a low depression.
This article presents results of construction and operation of multilateral wells. In 2017, the company drilled 3 multilateral well pilots with "fishbone" geometry. Among the subsidiaries of Rosneft Oil Company, leading the development of onshore fields, a record result has been achieved with 5,030 m penetration of the reservoir. The assessment of multilateral well production shows a 3.5-fold increase compared to standard horizontal wells.
To date, the first phase of pilot operation has been implemented:
- Selection of pilot sites, well design;
- Drilling wells with the selection of optimal technologies and determination of technological limits;
- Selection of pilot sites, well design;
- Evaluation of the actual productivity of MZS;
- Research of working intervals.
These works allow to drill high-performance multi-hole wells with high economic efficiency. The experience of our company in the construction of multilateral wells will allow us to make a more balanced decision in the dissemination of this technology at fields with similar geological and technical conditions.
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Seismogeological Model As a Tool for Making Business Decisions
More LessSummaryExploration of oil and gas fields of the Siberian Platform and other provinces is increasingly connected with the extremely high complexity of the geological structure and low rate of knowledge. There are significant geological uncertainties, the reduction of which is a key task for successful exploration and production drilling, the development system optimization. The comprehensive approach used by Gazprom Neft, described in the work, made it possible to increase the success of geological exploration and reduce capital costs due to a deeper analysis of the data.
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How to Avoid Pitfalls in Interpretation of 3D Seismic Data With Effects of Igneous Intrusion
Authors A. Batischeva, E. Danko, A. Petrov and A. MityukovSummaryIgneous intrusions have very difficult structure on Nepa-Botuoba anteclise. Earlier, when there were only archive 2D seismic data with well information it was possible only understand their locating. Because of the poor data quality it was not possible to study it correctly. However, after we received data of 3D seismic it became possible to study properly igneous intrusions and effects which they made on the layers under it. To understand morphology of the igneous intrusion and its effects on seismic data we made modeling, seismic attribute analysis and structural interpretation. In the result, understanding of igneous intrusion influence on the 3D seismic allowed to avoid pitfalls, and make correct structural and dynamic interpretation.
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The Finding Prospective Objects From Seismic Data by the Example of One of the Deposits of the Nepa-botuoba Anticline (NBA) of Eastern Siberia
Authors E.A. Danko, A.V. Gaiduk, V.A. Galiaskarov and E.I. GoguzevaSummaryThe article describes the approach of the interpretation of 3D seismic and well data of the hydrocarbon play in the region for the finding prospective objects and increases the resource potential of the Siberian Platform. Using the example of one of the areas in Eastern Siberia, the effectiveness of the described approach was demonstrated, the results were obtained.
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Sedimentation Conditions and Regional Sequential Stratigraphic Dismemberment of Vendian Terrigenous Deposits in the Southeast of the Siberian Platform
Authors E. Dolgova, V. Grinchenko, A. Yukhnevich, A. Gaiduk and N. RedkinSummaryThe Vendian terrigenous deposits are distributed practically on the whole southeastern part of the Siberian platform apart of paleo-elevations and basement heights. Many giant oil and gas fields (Chayandinskoye, Verkhnechonskoye, Dulisminskoye, Srednebotuobinskoe, etc.) are confined to the terrigenous complex one of them the giant Kovyktinskoe field with gas reserves of 1.9 trillion m3. But despite so many discoveries in the terrigenous complex, there are a lot of problems related to prediction of the distribution of the reservoir and its properties.
There are many problems not only at the stage of geological exploration work, but also at already exploited fields, which can lead to a significant reduction of the resources. To reduce risks during geological exploration it is necessary to understand the geological structure of the terrigenous complex and the features of its accumulation and facies variability. In this article, a step-by-step was considered accumulation of Vendian terrigenous deposits, conditions for complex formation were identified and regional sequence stratigraphic partitioning of the section was carried out, which in future can form the base for prediction of reservoir distribution zones with advanced reservoir properties.
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The Main Types of Perspective Objects of the Nepa-botuoba Anteclise and Features of Their Geological Structure
Authors A. Gaiduk, V. Grinchenko, A. Chirgun, V. Galiaskarov and A. FilichevSummaryMany oil and gas fields have been discovered in East Siberia, including in the area of the Nepa-Botuoba Anteclise. However, the degree of understanding of the distribution of these deposits remains low, therefore, the search for new hydrocarbon fields in the region requires the use of high-tech methods of work with geological and geophysical information.The greatest risks in the search for new hydrocarbon fields are associated with the presence of a collector. This is due to the lateral heterogeneity of rocks, secondary changes, mainly salinization, as well as other features of sedimentation. The key task of exploration in the Nepa-Botuoba Anteclise area is to search for areas of reservoir development with improved porosity and permeability values.
This article shows which objects are perspective on the territory of the Nepa-Botuoba Anteclise and their key characteristics, features of the structure and search features.
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Special Processing of Wide Azimuth 3D Seismic Surveys in Seismic Conditions of the Siberian Platform
Authors A. Kleshnin, D. Tverdokhlebov, A. Chirgun, A. Filichev and S. GolopapaSummaryThe work describes an approach to processing wide-azimuth 3D seismic surveys in the complex seismic conditions of the Siberian Platform. On the example of one of the areas in Eastern Siberia, the efficiency of special processing of wide-azimuth data was demonstrated. The features and advantages of the developed processing flow are compared with the standard approaches.
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The Foundation and the Bark of Weathering Within the Chon Group of Fields
Authors V. Pustylnikova, N. Sentyakova, N. Ivanova and V. VorobyevSummaryWithin the Chon group of fields, the petrographic composition of Foundation rocks and weathering crust was studied, the profile of the residual weathering crust and Foundation variability was determined and typed. The obtained results, after linking with GIS and 3D seismic data, can be used to predict the thickness of weathering crust, faults in the Foundation and refinement of its block structure, as well as in the reconstruction of the paleorelief of the crystal Foundation at the time of formation of basal horizons. The study of the profile of the residual weathering crust have led to the conclusion about the existence of arid climate at the period of its formation and accumulation of basal layers of the sedimentary cover, which in turn characterizes the type of the sedimentary basin, the composition of the original precipitation and their cementing substances, as well as, in some sense, determines the post-sedimentary processes.
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Sedimentary, Structural, and Migration Factors Improved Porosity and Permeability Values in Deposits Over the Basement Highs on the Nepa-botuoba Anteclise
Authors N. Redkin, A. Gaiduk, A. Petrov and A. MituykovSummaryDeposits in Ust-Kut horizons above the basement high are one of the most productive objects in carbonate sedimentary cover deposits in the territory of the Nepa-Botuoba Anteclise.
Despite the presence of search features expressed in the results of the seismic data, a unique model of the formation of the nature of improved porosity and permeability values does not yet exist.
The authors of the article analyzed the possible causes of the formation of improved properties in Ust-Kut horizons over the basement highs and formulated a conceptual model of the formation of deposits. The presence of improved porosity and permeability values in Ust-Kut horizons is associated with a combination of sedimentation, paleostructural and migration factors
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Problems of Interpretation Archive Seismic Data in East Siberian
Authors I. Shipilov, D. Tverdohlebov, A. Gaiduk and N. PopovaSummaryThe territory of East Siberian have been exploring since 60s years of last century till now days. A lack of productive capacity of computing techniques and imperfection of methods of seismic prospecting in last century didn't allow to set off fully the effect of complicating geological factors. This was the reason for the low quality of the stacks data. Follow-up active technological evolving caused to appearing qualitatively new type of seismic results, and, therefore, to the common heterogeneity of archive data, dependent of survey's year, so that must be considered during interpretation them
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The Results of the Gravity Survey in the Nalaykh Basin (Mongolia)
Authors B. Buyantogtokh, E.Kh. Turutanov and B. TengisSummaryAs a result of gravimetric studies, characteristics of the mesozoic structures and data on the morphological features of the submerged part of the crystalline fundament were obtained. According to the interpretation of gravity profile, Nalaikh basin has a complex block structure and it is divided into two main parts. The thickness of the Mesozoic deposits in the center of the basin is about 600 m.
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Tectonophysical Approach to the Analysis of Geological and Geophysical Data at the Kovykta Gas-condensate Field
SummaryIn the report the results of application of modern ways in the tectonophysical analysis of geological and geophysical data for identification of regularities in a fault structure of a platform cover on the Kovykta gascondensate field (GCF) are considered. The basis for research of sedimentary cover are the materials of 3D seismic and electromagnetic survey, the structural data and materials of digital relief model processing. As a result of the complex analysis the zone-block structure (ZBS) of the Kovykta GCF is established. It represents hierarchy of blocks which contact with each other on wide zones of short fractures concentration. The ZBS style is defined by domination of subhorizontal fault zones (layer-by-layer stripping) and subvertical zones of northwest and northeast orientations. The network of the fault zones was formed in four stress fields which correspond with the main stages of an adjacent Baykal- Stanovoy mobile belt development in the Paleozoic- Cenozoic. Some fields are reactivated in the Cenozoic under the influence of the gravitational processes connected with local lifted raisings of a relief. The zone-block structure of the Kovykta GCF is a basis for it's zonation on hydrocarbon productivity, overpressure zones, on degree of fracturing and types of stress state of rocks. The solution of this task will allow to receive additional substantiating for the choice of drilling site which can be passed without geohazards and with the prospect of detection of natural gas accumulation.
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Mapping of Complex Fractured-cavernous Overpressure Zones in the Sedimentary Cover of the Northeastern Part of the Angara-lena Step by Geophysical Data
Authors A.S. Smirnov, A.G. Vakhromeev, I.A. Shelokhov, V.V. Kasyanov, N.N. Yaitskiy and A.V. MakarovaSummaryWhen interpreting the 2D and 3D seismic data processed with standard graph, it is impossible to detect oil and gas reservoirs (fissured-cavernous and porous-fissured types) with high properties. The reason for this - the small size of caverns and fractures, saturated with fluids with abnormally high reservoir pressures (AHRP). In particular, in the south of the Siberian craton (the Angara-Lena step) by drilling at depths of 1.2-2.2 km in the geological section of the halogen-carbonate rocks, the presence of gas- and brine-saturated reservoirs of fractured and fissured-cavernous type was established. The reservoir fluid pressures are 2.3-2.6 times higher than hydrostatic pressures. Nowadays, due to increased interest of oil and gas companies and institutions to the study of fractured reservoirs in dense rocks of the sedimentary cover and crystalline rocks of the basement, methods for modeling the propagation of seismic (scattered) waves are actively developing. The paper is devoted to the special approaches in the processing technology - the interpretation of seismic data, which are aimed at an accentuated study of a natural fissure reservoir through a “cloud” of scattered waves, which gives a field independent of fluid saturation, a dataset that is somehow related to a fracture and cavernous - with a pore space. The fractured filtration system of the intersalt reservoir, having the same properties in the acoustic field as the above / lower-lying carbonate layers, in addition or in contrast to them, is additionally characterized by the parameters of anisotropy, inhomogeneity or mosaic laterally.
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Experience of Ground Penetrating Radar Application for Gold Exploration in the Eastern Sayan Geological Settings
Authors A.A. Otsimik, V.V. Leskov, V.V. Gomulsky and S.A. BezdenejnikhSummaryThe paper describes the geological aspects of one of the gold deposits of the Eastern Sayan, related to its structure and genesis. The technique and hardware used in geophysical studies are described. The results of Ground penetrating radar (GPR) studies and features of the field data interpretation are presented. The comparison of the GPR data with vintage transient electromagnetic data is shown. The criterias for gold ore mineralization zones and ore bodies identifying based on the results of geological and geophysical studies are described.
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An Aspects of Transient Electromagnetic Method in the Near Field Zone Resolution for Oil and Gas Exploration in the South of the Siberian Craton
Authors I.K. Seminskiy, I.V. Buddo and E.V. MurzinaSummaryOne of the most common electroprospecting techniques for the oil and gas exploration is the transient electromagnetic method in the near field zone (TEM).
The resolution of TEM (possibility of horizontally-lying layers separation) depends on rocks geoelectrical properties. The current exploration strategy of Russian Federation is oil fields exploration of groups 2 and 3 by geological structure. Hence the resolution assessment of the TEM for oil and gas exploration in the geological settings of the south of the Siberian craton is evident. It is possible to evaluate the resolution of the TEM using synthetic modeling. In this research, the capabilities of the TEM in respect of the oil and gas exploration in the geological settings of the Nepa and Kamov Archs, as well as the Angara-Lena step were examined.
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Geoelectric Model of the Section As an Integral Part of the Oil and Gas Fields Geological Model (Case Study From the Kovykta Gas Condensate Field)
Authors I.V. Buddo, A.V. Pospeev, I.A. Shelohov, N.V. Misiurkeeva, Y.A. Agafonov and A.S. SmirnovSummaryThe stages of geological exploration correspond to specific geological tasks, for which sequential complication is typical. At each stage of geological exploration, an appropriate set of research methods is used, optimal for solving the problems of necessary detail. Like complicating the set of methods, at each stage of geological exploration a geoelectric model is used - the result of electromagnetic exploration - with appropriate level of detail. In the paper, an example of the Kovykta gas condensate field is shown which represents the consistently increase the detail of geoelectrical models. Each level of detail corresponds to the class of geological tasks to be solved, starting from promising gas-saturated reservoirs mapping, ending with the fracture zones and possible geohazards while drilling prediction.
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Fractured Fluid-bearing Reservoirs in Magmatic Rocks Prediction According to Transient Electromagnetic Soundings Data
Authors A.I. Ilyin, D.V. Kolesnikov, I.V. Buddo, A.G. Vakhromeyev, I.A. Shelohov, Y.A. Agafonov and R.B. SultanovSummaryNowadays active cluster drilling of deep production wells is carried out at the oil and gas fields of Nepsko- Botuobinskaya anteclise. During the drilling, fluid-loss zones are fixed. Numerous geohazards are associated with the magmatic rocks intrusions. The volume of drilling mud lost reaches thousands of cubic meters. The mapping of fluid-saturated zones in magmatic rocks can be performed with transient electromagnetic soundings in the near field zone (TEM). According to the geological basis the magmatic rocks intrusion into the carbonate rocks should be accompanied by saline water saturation of fractures in the traps and host rocks which leads to abnormally low electrical resistivity. TEM survey allows delineating zones of fluid-saturated fracturing and, when comparing the drilling data and the resistivity of rocks, predict possible risks of drilling wells, eventually correcting the position of well clusters.
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Feasibility of Fault Zones Fluid Permeability Assessment From the Set of Geophysical Data
Authors N.V. Misyurkeeva, I.V. Buddo, I.A. Shelohov, A.G. Vakhromeev, Y.A. Agafonov, I.V. Gorlov and A.S. SmirnovSummaryThe paper shows approaches to investigating and mapping of the faults in the sedimentary cover, as well as evaluating their fluid permeability based on high-density geophysical surveys data: 3D seismic and 3D TEM survey. Due to the high spatial density and high vertical resolution, these techniques allow the faults mapping as well as fluid-permeability and colmatage evaluation.
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Estimation of the Oil Pipeline Interference for the Transient Electromagnetic Data Interpretation (Oil Field Production Stage)
Authors E.V. Murzina, V.S. Emelyanov, V.V. Gomulskii, A V. Pospeev and Y.A. AgafonovSummaryTransient electromagnetic method in the near field zone carried out within the dense observation grid is often used at the stage of field development, to determine the geoelectrical properties of the target horizons for further prediction of the reservoirs saturation. However, when electromagnetic soundings are carried out within the producing oil field, the interference of TEM data is unavoidable. Hence it is necessary to develop special approaches to interpretation of TEM data affected by pipelines. The paper presents the results of TEM data interpretation from a few oil field of Eastern Siberia.
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Magnetotelluric Data Interpretation for Highly Resistive Shallow Environment
Authors A.V. Pospeev and E. SenSummaryThe paper considered an approach to the magnetotelluric (MT) data interpretation regarding to the near-surface heterogeneity influence attenuation. The analysis of spatial conductivity distribution within the central part of Nepa-Botuobinskaya anticlise studied with transient electromagnetic method (TEM) in the near field zone was carried out. The geoelectric model was built based on typical quasi-longitudinal MT curve inversion of the south of Siberian craton. The model was adjusted by placing heterogeneities into the upper part of the section. Polarization curves for electric and magnetic fields had been calculated for this model with respect to the galvanic shift. Acquired data had been spatially filtered. According to the conducted research results the approach to the near-surface heterogeneity influence attenuation for MT data interpretation was proposed.
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Transient Electromagnetic Method Efficiency Assessment for Oil and Gas Exploration (Based on the Forward Modeling Results)
Authors Z.Y. Shobohonova, O.V. Tokareva, S.V. Kompaniyets, I.V. Buddo and V.V. GomulskiySummaryThe success of the geophysical methods application for oil and gas exploration depends on the reservoir physical properties contrast. To choose the applicable geophysical methods, geological and geophysical modeling is performed. The paper shows the methods and results of TEM data forward modeling for various HC-prospective reservoirs of Western Siberia.
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Reducing Uncertainties in the Elastic-velocity Model of the Upper Part of the Section Construction by Tem Data Applying
Authors I.A. Shelokhov, I.V. Buddo and A.S. SmirnovSummaryAreas of permafrost rocks distribution occupy about 5 million sq. km of Russia territory. When processing seismic data in areas with permafrost rocks, its influence should be taken into account. Ignoring the complicated structure of permafrost zone can lead to significant errors in prospective horizons structure. Static corrections calculation by conventional methods (by smoothing the variations of the travel time) sometimes can result in artificial synclines arise on the section. The authors propose an approach to the elastic properties of the upper part of the section recovering from Shallow TEM data.
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Transient Electromagnetic Data Forward Modeling Reservoir Saturation Assessment
Authors Z.Y. Shobohonova, O.V. Tokareva, V.V. Gomulskiy and I.V. BuddoSummaryThe transient electromagnetic method in the near field zone (TEM) is widely used for oil and gas exploration in the Eastern and Western Siberia geological patterns. To assess the possible effectiveness of TEM in certain geological settings, a special technique of forward TEM modeling has been developed. The paper shows innovative approaches to the TEM forward modeling. It is shown that the synthetic simulation of the TEM signals makes it possible to evaluate the possibility of separating promising zones with different reservoir saturation.
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Conditions for the Formation of Neoproterozoic Sedimentary Rocks of the Oselok Group in the Sayan Region
Authors Z.L. Motova, T.V. Donskaya and D.P. GladkochubSummaryWe present the results of integrated studies of clastic sedimentary rocks Oselok group in the Sayan region. On the basis of petrographic, geochemical and U-Pb (LA-ICP-MS) geochronological studies it was found that the upper and lower parts of the cut of the Oselok group reveal certain differences. On the basis of identified features, it is anticipated that during the accumulation of terrigenous rocks Oselok group a change of the geodynamic regime of the basin sedimentation.
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The Influence of Planetary Geodynamics on the Success of Geological and Technical Measures for the Development of Oil and Gas Fields
Authors D.V. Tomashev, M.V. Nelepov and A.A. PapotnayaSummaryThe analysis allows to draw a conclusion about the effect of planetary tectonic processes on local areas within oil and gas fields, as a result of which zones of increased fracturing are formed both in carbonate and terrigenous reservoirs.-Planetary forces, acting on tectonic elements of the first order, cause deformations in smaller elements up to the formation of a network of cracks and microcracks within the productive deposits.
The resulting network of cracks has a direction consistent with the planetary stresses and is identified as linear zones in the wells with the largest oil or gas production.
The obtained information should be taken into account when planning geological and technical measures: drilling, hydraulic fracturing, design of injection wells, etc.
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Forecast of the Current Phase State of the Hydrocarbon Accumulations of Ciscaucasia on the Basis of an Analysis of the Geodynamic Activity of the Scythian Plate
Authors D.V. Tomashev, M.V. Nelepov and A.A. PapotnayaSummaryThe genetic sequence of hydrocarbon accumulation locations inherent in primary hydrocarbon systems is often violated in nature. To forecast the current phase state of hydrocarbon raw materials during geological exploration and preparation of primary design documentation, including the development of deposits, it is necessary to consider in detail all stages of the geological development of oil-promising areas of the territory during which it is possible not only to form deposits but also their subsequent reformation and disbanding.
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Evaluation of 4D Effects Based on the Results of the Repeated Survey Within the Water Area of the Novatek Gas-condensate Field
Authors S.S. Sanin, V. I. Kuznetsov, Yu.N. Dolgikh and D.S. TataurovSummaryThe company NOVATEK performed in 2008–2010 the 3D seismic works within the aquatorial part of the gas condensate field.
The main geological tasks were the detailed exploration and forecast for the Cretaceous deposits’ reservoir properties.
To engage in development the new prospective targets in the underlying intervals, there was a 3D survey performed in 2017
Based on the results of the work, 2 sets of data were obtained for the same area within a time difference of 7–8 years, which provided the opportunities for estimating 4D effects of the tanks being in service all these years.
The report presents the results of modeling and analysis of the real 4D effects, characterizing the processes of development and operation, as well as pointing to the reserves of improvement of the efficiency of these processes.
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Formation Micro Imager (FMI) Processing and Interpretation in the Paleozoic Deposits
By S. ChizhovaSummaryStudying fracturing is a crucial aspect of pay zones prediction. Contemporary methods of studying rock formations allow to assess the fracturing of the formations examined and define their textural features. Formation Micro Imager (FMI) allows to solve the following challenges: identify the elements of structural abundance; define the angles of incidence and strike angles; identify thin bedded manifolds, determine the systems of fractures; determine the decompaction zones precisely; extract additional information about non core pay zones and select zones for testing. Formation Micro Imager (FMI) has already been used in geophysics, however, applying this method to effusive igneous sedimentary complex could solve certain unconventional challenges.
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Integrated Solution for Geological Modeling of Deposits. From Interpretation of Seismic to Structural Modeling With the Possibility of Estimating Uncertainties
Authors E. Volk and M. SafronovSummaryThe integrated solution implemented within a single interface and database has a set of innovative technologies for a full cycle of geological modeling, , from seismic interpretation to calculation of reserves, including on multivariate models, taking into account given uncertainties and risks.
The approach is based on the modeling graph - Workflow used to automate the process of modeling, updating and calculating the set of model realizations. The workflow is appropriate for the evaluation of significant contingent resources and for the reliable quantification of commercial reserves. It is also suitable for providing input to development plans and concept design choices, and for management of fields in early phases of production.
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Optimization of Field Development Into Account the Surface Networks, Through Integrated Modeling
By A. ZarovSummaryAt present, in conditions of unstable oil prices, the oil and gas fields development plans is associated with increasing efficiency and minimizing risks. The integrated model is single platform for optimizing development that, takes into account and the uncertainties accumulated in the geological and hydrodynamic models, and the limitations of the surface network. The paper contains an overview of the methods for constructing integrated models, and a description of their work. Data on possible program optimization algorithms are also included.
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Improvement of the Eastern Part of the Kovykta Gas Condensate Field Geological Model in the Light of the New Geological and Geophysical Data
Authors I.V. Gorlov, N.V. Misyurkeeva, I.V. Buddo, A.G. Vakhromeev and I.A. ShelohovSummaryThe modern geological model of the Kovykta gas condensate field is based on drilling more than 70 deep wells and 2D seismic surveys. In the course of carrying out high-density 3D seismic studies, transient electromagnetic soundings in the near field zone (TEM), deep drilling and geophysical well logging, the geological model undergoes adjustments. The paper shows the results of modern geophysical studies and drilling within the Kovykta gas condensate field, as well as their geological interpretation.
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Features of the Parfenov Reservoir Structure and Its Distribution Within the Kovykta Gas Accumulation Zone Based on Geophysical Well Logging and Tests
Authors P.N. Kokarev, I.A. Dikih and V.A. SerdyukovaSummaryFor the time being the Parfenov reservoir petrophysical model does not consider its content - sandstones differing in composition and properties. The paper describes the results of tests and well logs, which indicate the presence of a distinctly differentiated separation of the Parfenov reservoir-rocks by reservoir properties, both in area and in section. Conclusions inferred on the presence of Parfenov reservoirs with improved and deteriorated reservoir porosity and permeability. The wells of the Kovykta gas condensate field are ranked according to the type of the Parfenov horizon section.
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Secondary Vugs of Carbonate Rocks: the Role and Methods of Study
Authors V. Kolesov, A. Romantsov and D. NazarovSummaryThere are considered problems of revealing reservoirs while using classical deterministic approaches. In the article there was introduced an example of dissonance of permeability received by dynamic well testing and well logging data and core laboratory research data. We suggest a hypothesis concerning the presence of the tight filtering channels. There were presented the examples of the results of the core computer x-ray tomography. According to the results of the core x-ray tomography there was executed the cavernous voids classification. There was showed the importance of the oriented selection of the core samples for the cavernous voids filtrational characteristics examination. In the article there were performed the results of the reservoir porosity and permeability and filtrational experiments, besides, those results were compared with the results of examinations of the non-oriented samples. It was showed that the oriented samples permeability was significantly higher and water and oil saturation lower than the values reported earlier. There were considered the difficulties of the well launching according to the well logging data interpretation because of the rocks high variability.
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Hydrogeological Prerequisites for the Development of a Physico-geological Model of Zones of Abnormally High Reservoir Pressure at the Kovykta Gas Condensate Field
Authors A.G. Vakhromeev, I.V. Gorlov, A.S. Smirnov, S.A. Sverkunov and Yu.A. LankinSummarySince 1986, the authors have been working to substantiate the predictive-search complex of field geophysics methods that allow mapping of zones of increased water conductivity in the halogen-carbonate stratum of the Lower Cambrian and to approach the creation of a single physicogeological model of interfacial fractured carbonate reservoirs with abnormally high reservoir pressure (AVPD). Such a forecast is the basis for design decisions on the construction of production wells on the Parfenov horizon through inter-salt fissured carbonate reservoirs with the AVPD.
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Key Features of Processing for the Recovery of Dynamic and Kinematic Characteristics of the Wave Field
Authors D. Fedorova, V. Esaulov, O. Berkimbai, N. Zolotoi, P.S. Bekeshko, I.V. Shushkalova, E.M. Chub, A.S. Sorokin and P.P. YemelyanovSummaryIt is necessary to correctly execute the entire complex of modern processing procedures to obtain a qualitative result and the possibility of carrying out a further forecast using seismic data. It must be remembered that without an adequate solution of the kinematic problem, it will be impossible to restore the dynamic characteristics of the seismic record, and, consequently, to fulfill the forecast of the filter and capacitance properties in the inter-well space.
Within the framework of this work, the problems of restoring low frequencies of a useful signal and minimizing the influence of the complexly built upper and middle parts of the section were solved. The construction of a detailed anisotropic depth-velocity model and the implementation of anisotropic Pre-Stack Depth Migration, as well as the application of Robust Surface Consistent Decon and Overburden Compensation have made it possible to obtain data suitable for solving the geological tasks
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Perspective Ways to Improve the Accuracy of Measurements in Modern Gravity Prospection
Authors D. Andreev and D. MuhamadievSummaryThe maximum accuracy of field gravity measurements is currently needed to solve the following geological tasks: gravimetric search for hydrocarbon deposits, karst detection, monitoring the development of gas fields, deposits of high-viscosity oils and natural bitumen, monitoring the underground gas storage facilities operation, monitoring geodynamic sites of nuclear power plants. Improving the accuracy of gravimetric surveying is possible in several ways: preliminary testing of gravimeters at a certified gravimetric range, additional thermal insulation of gravimeters, rational equipment of gravimetric points, gravimeters protection from atmospheric influences and vibrations during transportation, high-precision geodesy. When carrying out gravimetric monitoring, in addition, it is necessary to take into account changes in the relief in the near observation points zone and changes in soil density (for example, due to changes in humidity). The above technological methods have been tested in practice and improved over the past decade by the specialists of the “TNG-Kazangeophysica” LTD in the Far North and Eastern Siberia harsh conditions.
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About Requirements to the Quality of the Field Material for Seismic Survey Production
By V.M. BolbatSummaryThe information about the current requirements of the Customers for the accuracy of the removal of the PGN, the evaluation of the effect of the angle of inclination of geophones on the quality of seismograms, the allowable spread of geophone impedances, the acceptable level of interference, the attribute estimation of data quality, the number of accumulations in the vibroseis are provided.
Suggestions on changing the allowances of conservative instructions of Customers are considered.
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Impulse Seismic in Eastern Siberia, New Approach
Authors V. Detkov and P. BalandinSummaryThe experience of seismic syrveing in the water areas of Eastern Siberia, in particular, on the rivers Biryusa, Chuna, Angara with the use of electromagnetic sources “Yenisei-VEM-50” and “Yenisei-VEM-100” showed that with very noisy field data as a result of geophysical processing, time sections suitable for solving geological problems. The transfer of the technique of continuous (dynamic) excitation from the water area to land could greatly simplify the technique of high-density imaging.
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Implementation of Projects in Eastern Siberia, Best Practices
More LessSummaryEvidence on the best practices, from the experience of GEOTEK -East Geophysical Company Ltd. are presented.
The experience of using environmentally safe pulse sources of excitation of the Yenisei line is considered. Evidence on the results of the application of the UniQ technology - supercompact seismic prospecting 3D. The experience of using the air laser scanning technology at the facilities in Eastern Siberia is highlighted.
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Increase Work Safety for Seismic Surveys
More LessSummaryPriority for PJSC “GEOTEK Seismic exploration” is the health and safety of the company’s employees, creating the necessary working conditions - competent and safe organization of the workplace, raising the competence of employees in the field of labor protection. The experience of applying the 5-year strategic model of the function in the field of labor protection, industrial and environmental safety is considered. As a result of the implementation of the strategy, it has been possible to reduce injuries fourfold in the last three years.
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High-resolution Seismic in Siberia and 3D Surveys in Transit Zones
By V.M. BolbatSummaryEvidence on the work experience of PJSC GEOTEK Seismicservices technology on high-resolution seismic exploration technology in Eastern Siberia and Yamal-Nenets Autonomous District (YNAD) are presented. The applied data collection and processing systems, the quality of the source material.
The experience of summer work in transit zones with the use of an aqueous modification of a pulsed electromagnetic source VEM-50 is considered.
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Integration of Different-scale Geological and Geophysical Data for the Geosteering Wiring at Chona Project
Authors V.A. Fagereva, K.W. Zverev and P.P. YemelyanovSummaryThe integration of the methods gave an opportunity to work out the most complete model of the spatial distribution of the facies of the B13 formation. Changes in the sedimentation model allowed to determine the most probable zone for the reservoir and to correct the trajectory of the horizontal wellbore.
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Multidisciplinary Approach for Petroleum Play Reconstruction of Dislocated Heterogeneous Carbonate Reservoirs Within the World's Most Ancient Riphean Formation
Authors R. Khusnitdinov, D. Kalacheva, N. Morozov, A. Vazaeva, R. Oshmarin and S. NaumovSummaryThis paper concerns the variety of geological uncertainties of unique ancient carbonate (fractured crystalline dolomite) reservoir. 1st phase of the entire project is nowadays successfully prepared to development, but it took more than 30 years, since the relevant technologies were obtained. 2nd phase of this project being poorly studied includes up to 30% of resources and is located 50 km to the East. Key challenge is connected to very complicated reservoir geometry and internal structure, which is characterized by uncertain stratigraphic and reservoir boundaries and blocks saturation.
The main objectives of this investigation are to design, to perform and to analyze research program based on historical wells core and fluid samples and, as a result, to reconstruct petroleum play for this Eastern part of the field in order to organize most effective exploration activities.
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A Successful Implementation of Diving-wave Refraction Tomography for Near-surface Velocity Model Building in East Siberia
Authors O. Berkimbay, P. Bekeshko, A. Sorokin and I. SafarovSummaryThe near-surface of Ignyalinksoe field is characterized by its complex structure. High velocity contrast anomalies related to thrust faults create challenges for seismic data processing and further quantitative and qualitative seismic interpretation. The compressional velocity of the near-surface varies between 1000 and 6000 m/s. It is widely recognized that inability to properly resolve anomalies at the upper part of the initial velocity model can lead to artefacts at later stages of velocity model tomographic updates. These artefacts can then cause poor imaging of the target during depth migration and signal distortion.
Due to the reasons mentioned earlier it was decided to implement Diving-Wave tomography for PSDM velocity model building at the near-surface. This is the first time of application of this technology for the complex conditions of East Siberia. DWTomo is a 3D tomography which can resolve complex high-contrast velocity anomalies.
The obtained image obtained after the Prestack Kirchhoff Depth Migration with DWTomo incorporated at the top of the model shows a dramatic improvement compared to the previous processing. The negative impact on the amplitudes and structure of the target horizon is noticeably minimized.
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Structural Framework and Tectonic Settings of Frontal Part of Predpatom Fold-belt (Ignyalin Area)
Authors A.A. Iskhakov, D.V. Khipeli, S.A. Korneeva, A.A. Aseev, V.S. Vorobev and A.V. MigurskySummaryThe paper explains the results of structural and paleotectonic interpretation of well and 3D seismic data of the frontal part of Predpatom fold-belt (Nepa-Botuoba arch). Geological support of seismic data processing allowed to make a detailed interpretation of faults and shears and identify the sequence of fault zones development.
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Myths About Reefs. Experience in the Investigation of the Geological Structure of Carbonate Deposits Using Seismic Data
SummaryThe article describes the most common myths about the interpretation of seismogeological data in reef reservoirs. They are illustrated by examples of several fields in the Timan-Pechora, the Caspian Sea and East Siberian regions. These include such thoughts as “there are no reflections inside the reefs”, “the reef has a homogeneous internal structure”, “organogenous structures are always visible on the seismic section”, “reefs in the presence of a section will have the greatest prospects in terms of oil and gas in carbonate section ”and others. Each thesis is illustrated by an example obtained by the authors, from the experience of working with bioherms in the seismic projects. In each case it is necessary to search for the pattern in view of the degree of knowledge, the quality of seismic materials and the complexity of the reservoir. However, the universal key to understanding any reef reservoir can be a detailed approach to seismic data processing, Rock Fisciss analysis, inversion and complex seismic geological interpretation.
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Suppression From the Seismic Data of the Multiple Diffracted Interference Waves From River Networks Reverberating in the Upper Layer
SummaryThe combination of specific near-surface conditions associated with the shape of river banks, as well as the presence of a sharp jump in the acoustic impedance under these rivers, such as salt lenses, leads to the formation of multiply diffracted interference waves reverberating in the upper layer and appearing on seismic data as repeatable diffractions with peaks, which are focused in the footprints of the rivers after migration. These prints repeat the shape of the rivers and are clearly visible on horizontal time slices in different time intervals.
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Rock Physics Study of the Complex Terrigenous Reservoir of One of the Deposits of Eastern Siberia
Authors A. Shcherbakova, S. Zakharchuk, L. Abdrakhmanova, L. Kibalchich, N. Zolotoi, S. Frantsuzov and V. VorobievSummaryRock physics model building and geological stochastic modeling as a route to increasing of the reliability of the seismic reservoir properties prediction of complex terrigenous deposits of Vendean age. Application of the methods proposed in this paper allowed to choose the optimal approach to the interpretation of seismic inversion results, as well as to estimate the uncertainty factors of the obtained model, related to the effect of complex geological and geophysical conditions in the area.
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Scanning the Earth - a Comprehensive Analysis of Borehole Images and Core Data. Case Study of Vendean Clastic Formation of Eastern Siberia
Authors A. Islamov and N. BelyaevaSummaryVendean clastic formation of Nepsko-Botuobinskaya anticline is one of the most complex reservoirs of East Siberia of Russia. Main uncertainties related to prediction of reservoir rocks by standard well logs and limited predictability of current geological model. By using integrated approach to the analysis of the Core data and Logs, with borehole images (FMI) as tool for this integration, comprehensive analysis performed, including from detailed depth-matching to complex sedimentological analysis of reservoirs. Detailed sedimentological description of Core was improved by adding information of dips and azimuth of interpreted sedimentological surfaces. This information gives us understanding of the direction of paleocurrents which help in facial prediction and reservoir geometry analysis.
As a result, flow directions trends within the lower basal part of Vendean section shows strong dependency with existed relief and paleovalleys. In the middle part of lower reservoir image logs confirmed our conception in regional paleoslope direction. Upper part of the lower reservoir shows bimodal reversal directions of cross beds, which gives along with texture features of Core influence of tidal activity of the sea and shift from continental area to transitional zone. Upper reservoir shows very different flow direction from the expected, which can be explained by transformation of territory which is also shows by well-to-well correlation based on sequence stratigraphic principles.
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