- Home
- Conferences
- Conference Proceedings
- Conferences
6th EAGE Saint Petersburg International Conference and Exhibition
- Conference date: April 7-10, 2014
- Location: Saint Petersburg, Russia
- Published: 07 April 2014
61 - 80 of 174 results
-
-
Efficient Numerical Simulation of Exploding Reflectors for 3D Heterogeneous Multiscale Media
Authors V. Cheverda, E. Landa and G. ReshetovaSummaryCommon Middle Point seismic sections and their successive time migration provide extremely important knowledge about the internal structure of the 3D heterogeneous geological media and are key elements for successive geological interpretation. Full scale numerical simulation, that is one which starts with single shot seismograms, provides a deep understanding how the features of the image are linked with its subsurface prototype. Unfortunately, this kind of simulations for realistic geological media and 3D seismic surveys needs huge computer resources, especially for simulation of seismic waves’ propagation through multiscale media like cavernous fractured reservoirs. In order to significantly reduce the query of computer resources we propose to model these 3D seismic cubes directly rather than shot-by-shot simulation with subsequent CMP stacking. In order to do that the well known “exploding reflectors principle” is modified for 3D heterogeneous multiscale media. Its parallel implementation allows modeling of realistic 3D Common Middle Point stacks with reasonable computational costs. Numerical results for simulation of Common Middle Points sections and their time migration are presented and discussed.
-
-
-
Simulation of Seismic Wave Propagation in Models with Complex Free-surface Topography
Authors J. Diaz and V.V. LisitsaSummaryThis paper presents an algorithm for the numerical simulation of seismic wave propagation in models with complex free-surface topography. A free-surface is approximated accurate enough by a triangular mash after that the discontinuous Galerkin (DG) method is used to solve the elastic wave equation. However, the DG is more computationally intense than the staggered grid finite differences traditionally used for seismic modeling. The presented algorithm is based on the coupling of the two methods, so that the DG is applied only in a narrow near-surface part of the model, while the highly efficient standard staggered grid scheme is used elsewhere. This combination allows one account for the topography but keep the efficiency of the finite-difference simulation.
-
-
-
Mitigation of the 3D Cross-line Acquisition Footprint Using Separated Wavefield Imaging of Dual-sensor Streamer Seismic Data
Authors M.T. Farouki, A. Long, R. Jones, Y.A. Chim, M. Tang, H. LeGleut, S. Lu, D. Whitmore and R. van BorselenSummaryLundin Malaysia BV completed the first-ever application of separated wavefield PSDM imaging to 3D dual-sensor streamer seismic data as a test to improve shallow geological interpretation. The methodology exploits the illumination corresponding to surface multiple energy, and thus exploits what has historically been treated by the seismic industry as unwanted noise. Whereas a strong cross-line acquisition footprint affected the very shallow 3D data using conventional processing and imaging, the new results yield spectacular continuous high resolution seismic images, even up to and including the water bottom. One implication of these results is that very wide-tow survey efficiency can be achieved without compromising shallow data quality if dual-sensor streamer acquisition and processing is used, even in very shallow water areas such as that discussed here. The imaging methodology can account for all degrees of lateral variability in the velocity model, full anisotropy can be accounted for, and angle gathers can be created to assist with velocity model building
-
-
-
Simultaneous Long Offset (SLO) – A Case Study in Long Offset GeoStreamer Seismic Acquisition & Processing
Authors R.G. van Borselen, A.S. Long, E. von Abendorff, M. Purves and J. NorrisSummaryAn innovative 3D towed streamer project in offshore Gabon used a dual-vessel continuous long offset streamer configuration to acquire 0–12 km offsets with ten dual-sensor streamers. Streamer control for the 6 km streamers was robust and avoided operational complications or logistical penalties.
In simultaneous acquisition, data can be recorded with a temporal overlap between two (or more) simultaneously fired shots. Using random dithered time delays when firing the sources ensures that in certain domains coherency-based methods can be utilized to separate the simultaneously recorded data.
Simultaneous shooting maximized inline shot density for long record lengths, thus capturing unaliased deep target reflections from rugose base-salt and sub-salt horizons. Survey design benefited from prior 2D survey experiences with a variety of broadband source and streamer technologies, and the use of 2D streamers as long as 12 km.
3D illumination modelling further suggested that offsets as long as 16 km could be expected to yield useful base-salt and sub-salt reflections.
Wavefield separation processing yielded full receiver-side deghosting onboard, followed by an inversion-based separation of simultaneous shots onshore.
The ultra-long 12 km offsets combined with strong amplitudes of deghosted low frequencies have yielded encouraging sub-salt and pre-salt imaging.
-
-
-
How to Get Wider Bandwidth in Land Seismic?
More LessSummaryTo Successfully Define Hydrocarbon Reservoirs And Characterize Reservoirs Of Different Types, Explorationists Need To Expand The Seismic Bandwidth From Current 3 Octaves (Say, 10–80 Hz) To 5–6 Octaves Toward Both Low And High Frequencies. To Acquire Such High-Resolution Seismic Data On Land, New Integrated Technologies Should Be Developed. These Technologies Includes Such Components As 1) Point-Source And Point-Receiver Acquisition, 2) Excitation And Recording A Wideband Signal, 3) High Spatial Sampling To Ensure Good Distribution Of Azimuths And Offsets In The Bins, 4) High Accuracy Of Source And Receiver Positioning.
-
-
-
Selection of the Sampling Interval in Seismic Data Recording
Authors M.S. Denisov and A.V. CherepovskiySummaryThe sampling theorem states that a continuous analogue signal with limited (finite) spectrum can be uniquely recovered using signal’s discrete values taken at the frequency at least twice higher than the doubled upper frequency of the signal. At the same time the seismic records have limited length, and the amplitude spectrum of the seismic records is not finite. Consequently the process of discretization and recovery of the seismic signals inevitably cause amplitude distortions. The first type of distortions occurs in the process of trace recording, and the second type of distortions occurs at the data processing stage. Modern seismic is thought to ensure high resolution and reliable results of the investigation of the sedimentary cover. Seismic data are used to extract such characteristics of subsurface formations as lithology, fracturing, porosity, fluid saturation, etc. To successfully perform seismic inversion, errors related to signal discretization should be controlled and minimized. We offer a universal procedure of the selection of seismic data sampling interval.
-
-
-
The Modern Technology of Seismic Prospecting with the Use of Reflection Method Applied to Oil and Gas Exploration
Authors S.B. Kireev, V.S. Litvinenko and A.N. TeleginSummaryPeculiarities of the modern seismic prospecting technology applying reflection method (OGT-3D) are considered.
The conducted seismic works should result in detailed data about elastic behavior of the geological section under study. The data are received with the use of kinematic and dynamic properties of the records. Elastic behavior is connected with the composition and conditions of sedimentation and rock formation that are essential for geological interpretation of seismic data such as prediction of the geological structure of the area under study and probable mineral deposits (oil, gas, coal etc.).
The seismic prospecting is optimally used for prospecting and exploration of oil and gas deposits. Technology parameters correlate with the geological structure complexity in the areas of sedimentation. The modern seismic prospecting makes it possible to predict the location of oil and gas deposits with high probability (on shore and in offshore areas), that is why seismic prospecting is included into essential works for all probable wells. This approach allows to reduce the number of non-productive wells and cut costs of exploration of oil and gas deposits.
The method has proved high geologic and economic efficiency in the field of oil and gas exploration. Thus the method turns into an industrial branch capable of solving fuel and energy tasks. Oil seismic prospecting costs account for 90–95% of total field geophysics expenses.
The paper gives examples of MOV-OGT seismic prospecting implementation in the prospective areas of Timano-Pechorskaya province
-
-
-
Survey Design Considerations for Anisotropic Model Uncertainty Analysis
Authors L. Mulisheva, K. Osypov, N. Moldoveanu, O. Zdraveva, M. Woodward and Y. YouSummaryModern seismic acquisition geometries tending to cover all azimuths and increasingly growing offsets enabled a step change in illumination and quality of images, in particular in complex geological environments, as sub-salt. The paper discusses the impact of angle range in image gathers on uncertainty of anisotropy modeling. Various illumination scenarios were analyzed using tilted transverse isotropy (TTI) models over a field in the Gulf of Mexico.
-
-
-
Problems of Seismic Acquisitions in the Conditions of the Eastern Ciscaucasia
Authors M.V. Gubarev and S.L. ProshlyakovSummaryThe main reasons, reducing the effectiveness of vibroseis survey for the study of oil objects in the Eastern Ciscaucasia are discussed. Appropriate for the complex fracture upper Cretaceous deposits
-
-
-
Some Aspects of Seismic Data Preparation for Inversion
Authors M. Romanenko, S. Iliine and A. KharitonovSummaryThe report presents a number of approaches that have been developed through collaboration between processors and interpreters for seismic data preparation for the calculation of the inversion
-
-
-
Seismoelectric Imaging Using Virtual Electrode Scanning
More LessSummarySeismoelectric scans can be used for direct mapping of the electrical and hydraulic properties of oil and gas reservoirs or acquifers. The scans involve virtual seismic electrodes which are produced by focusing acoustic energy at known positions in the subsurface and at known times. If the acoustic focus point coincides with a discontinuity in electrical and hydrological medium properties, then it generates an electric current density which leads to a difference of potential that can be observed with remote electrodes. Although seismoelectric phenomena are not new, subsurface monitoring using virtual seismic electrodes provide a huge improvement over existing methodology for two main reasons: the source of the seismoelectric conversion is localized in space, and the energy at the conversion point is maximum. The seismoelectric source behaves like a controlled electrode whose properties depend on the acoustic energy pumped into the ground and on the local medium properties. By changing the position of the focus point through appropiate time delays of the acoustic sources, we can scan the medium properties and produce a map of its properties. This map can either be used directly, or it can aid electrical tomography by increasing its resolution and robustness.
-
-
-
Multicomponent Seismic Survey in Transition Zone of Pechora Bay with Node System Turtle-500
Authors Y.V. Roslov, A.A. Merezhko, V.V. Polovkov, D.A. Popov and E.G. ZhemchuzhnikovSummaryIn the period from June 18th to August 1st, 2013 “SEISMOSHELF” company performed 2D 4C(3C) multichannel seismic acquisition in the area of the Pechora Bay and its adjoining land.
The Russian-made seismic complex “Turtle-500” (“SEISMOSHELF” LLc, Saint-Petersburg) based on autonomous marine bottom modules (nodes) was used as a seismic recording system. The nodes are designed for recording of 4C seismic data at depths up to 500 m in seismic acquisition on basis of reflected and refracted waves; in landscape conditions that don’t allow the passage of a seismic vessel with a streamer, in shallow water, in places where it is difficult or impossible to use an ocean bottom cable, as well as on adjoining land and for seismic monitoring purposes.
The survey was carried out in full and high-quality multi-component seismic data has been obtained for the project area. Investigations done have confirmed that Russian innovation technology can be applied for transition zone and shallow water seismic projects.
-
-
-
The Prospective Exploration Of Russian Arctic Continental Shelf
More LessSummaryAccording to the quantitative estimate of hydrocarbon bearing prospects as of 01.01.2009, Arctic waters have the greatest resource potential (87% of offshore potential resources). Made in recent years, integrated regional seismic survey from federal budget resources revealed a significant amount of oil and gas prospective structures. Today, the license areas issued by companies and their applications for licenses cover almost all prospective oil and gas offshore areas.
-
-
-
Tectonics, Sedimentation And Hydrocarbon Prospectivity Of The South Barents Sea Region
Authors V.N. Koloskov, D. Nadezhkin, O. V. Pinous, O.V. Chernova, A. Aseev, L.M. Surguchev, E. Bykova and A.S. RabeySummaryAn integrated study has been conducted for the area of the southern part of Barents Sea. The detailed comparison of the stratigraphic patterns of the Norwegian and Russian parts of the shelf has been performed for the entire interval from Carboniferous through Jurassic. The ages of the key tectonic events, have been verified. Investigation of core data with seismic facies analysis enabled to improve determinations of determinations depositional environments and paleogeographic reconstructions. The best reservoir quality rocks are expected to be present within the Triassic shallow marine to fluvial sediments of Snadd, Kobbe andHavert formations, as well as JurassicStоandNordmela. Among the most interesting interval of the Paleozoic sections there are siliceous spiculites of Roye formation, which may contain good reservoirs in zones above Sakmarian-Artinskian bioherms. The most obvious structural traps have been developed above the salt pillows, and additional prospects may be present at the flank zones of salt diapirs
-
-
-
Sedimentary Environments in Cenozoic Basins of the Okhotsk-Bering Sea Region and Specialities of Oil and Gas Source Rock
Authors B.V. Senin, E.A. Lavrenova and M.E. EreskoSummaryPaleogeographic reconstructions of sedimentary basins of the Bering Sea and the Sea of Okhotsk in Paleoсene - Eocene, Oligocene-Miocene, and Pleiocene-Quaternary time have been performed in the framework of the presented work. It is found that frequent alternation of different sedimentary environments varying from continental erosion and denudation hilly plains to the relatively deep marine outer shelf took place within the studied shelves during Cenozoic. Possible occurrence areas of oil and gas source rocks of variant quality are predicted in Paleogene and Neogene sediments offshore and on contiguous land on the base of the reconstructions and results of organic matter studies in wells. The obtained results form a part of the required input data set used for modeling of generation-accumulation systems of the Bering Sea and the Sea of Okhotsk.
-
-
-
Multicomponent Marine Seismic Survey In The Arctic Shelf On The Base Geospace Technology
Authors S.A. Nechkhaev, G.S. Kazanin, G.I. Ivanov, A.V. Zimovsky and V.A. ShedrovSummaryIn July-September2013 on the Arctic shelf within 2 regional projects of “MAGE” seismic workperformed 2D-4C totaling 400 linear meters. Km using subsea system cordless battery seismic waves typeOBX Geospace produced by OYO Geospace Ind.(USA). In regional marine seismic studies use OBX Geospace Arctic shelf technology has been developed to record the seismic signal in the depth range 0 +1 / −50 m quality seismic data to a greater extent dependent on hydrological and weather conditions in the study area , and was not uniform due to the geological conditions volatile medium. As work and promotion of Baydaradskoy lips to North Yamalledge , an increase in the ratio of C H horizontal geophones . Quality Control H and Z components was conducted programs ProMAX R5000 and SeisWin QC. Given the heterogeneous nature of NSS in the project area, an analysis of the data obtained by X, Y components that showed the possibility of registering the PS waves with low noise level in the shallow waters of the Arctic shelf. Taking into account the large meridional extent of the work area, it was found similarities adjacent waters of the western Priyamalya in nature geological structure of the upper part of the section where universally developed alopecia permafrost.
-
-
-
Palaeogeography of the North-Eastern Black Sea and the Western Caucasus in Mesozoic and Cenozoic
Authors B.V. Senin, M.V. Kruglyakova, E.A. Lavrenova, M.I. Leonchik and A.A. GorbunovSummaryReconstructions of paleo-sedimentary environments in the North-Eastern Black Sea were intended to achieve three main objectives: to forecast the geographical range and depositional environments of potential oil/gas source rocks, reservoirs, and seals; to study sedimentation environments in the areas of fields - analogs for the purpose of quantitative assessment of prospective targets’ potential in the Black Sea Basin, to prepare a necessary part of input data for three-dimensional basin modeling and prediction of oil and gas occurrence offshore.
The research results indicate that, reasoning from sedimentation environments, Middle Jurassic, Lower and Upper Cretaceous, and Maikopian clayish deposits accumulated in the deep-water environments of the outer shelf and continental slopes of age-appropriate paleobasins, may have oil and gas source rock properties.
Reservoirs may be represented by Upper Jurassic shelf carbonate deposits, Lower Cretaceous clayish carbonate deposits, Upper Cretaceous carbonate deposits, Maikopian and Middle-Upper Miocene coastal or deep-water ( turbidite ) terrigenous deposits.
Terrigenous and terrigenous-carbonate deposits of different horizons in the sedimentary section may serve as cap rocks.
-
-
-
How to Benefit from Monte Carlo Simulations in Petroleum Systems Modelling to Estimate the Amount of Erosion?
Authors K.J. Zieba, M.C. Daszinnies, S.J. Lippard and A. LotheSummaryErosion estimates are crucial in reconstructing the burial history of the Barents Sea basins, where the lack of major success in oil exploration is attributed to the Cenozoic uplift and erosion. The magnitude, lateral and temporal distribution of erosion estimated by methods like AFTA, VR or by deterministic basin modelling often leads to very different results and/or does not account for uncertainties inherent to input data. Here, this challenge was approached by using Monte Carlo - secondary migration basin modelling simulations, where input data (early and late Cenozoic erosion episodes and palaeo-thermal gradients) were described by probability distributions, and model results were evaluated statistically.
Two overpressure scenarios were also considered in the modelling. Constrained a posteriori erosion parameter distributions showed a relatively narrow range of possible solutions. It was shown that the early Cenozoic erosion episode was more severe than the late Cenozoic event. A posteriori distribution mean values were much lower than a priori mean values (which represent initial beliefs) suggesting lower amount of erosion than expected. Overpressure modelling does not affect the minimum and the maximum erosion amount estimates to a high degree. Slight differences might be however observed for the early Cenozoic erosion event.
-
-
-
Geological and Geophysical Deep Structure Researches of Northern Eurasia in the Zone-block Model of the Earth’s Crust
Authors A.S. Egorov and V.D. GulinSummaryInvestigations of the deep crustal structure of the continents and their passive margins along the supporting geophysical profiles, within the framework of small-scale geological mapping and regional studies of large economic geologic regions, based on the broad base of regional geophysical surveys, opening way to development schemes, maps and sections of the new type.
Solution of the incompatibility problem of heterogeneous geophysical information and improve the reliability of interpretation constructs seen in the postulation of several key positions: a) deep crustal section are documents tectonic content; b) the deep cuts seen as components of a three-dimensional model of the region geotectonic research; c) the interpretation of the geophysical data is within the “zone-block geophysical models of the Earth’s crust”, the main elements of which are the blocks (paleoplity) with the ancient seismically layered continental crust, manifesting as the stationary regions calculated seismic, geoelectric, gravimetric, magnetometric, geothermal parameters and sharing their interblock sutures structure (tension, compression and fault) - gradient zones of geophysical fields.
In this methodology, performed mapping the deep structure of consolidated basement and platform cover of the continental territory of Russia, an extensive system of deep sections of the Earth’s crust along the profile of the regional DSS-ECWM, DRS-CDP, MTZ.
-
-
-
Gas Potential of the Kuff fm in Western Kurna-2 Field, Iraq
By K.A. TaovSummaryПроведена работа по синтезу имеющегося материала по геологии региона из отечественных и зарубежных источников.
Построены модель погружения и оценены темпы прогибания бассейна осадконакопления, что позволило реконструировать обстановку, что соответствует росту карбонатных (рифовых) построек, их литологические и коллекторские свойства.
-