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Marine Technologies 2019
- Conference date: April 22-26, 2019
- Location: Gelendzhik, Russia
- Published: 22 April 2019
41 results
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The Results of Characteristics of Vertical Arrays of Marine Pneumatic Sources
Authors V. Gulenko, E. Zakharchenko and A. RudakovSummaryThe paper deals with the simulation results of some characteristics of vertical arrays of pneumatic sources for marine seismic exploration. For the model in the form of a homogeneous vertical group of pneumatic sources with the same volume, located with a constant step in depth, the calculations of frequency characteristics, radiation patterns, signals and amplitude spectra for two different modes of starting the sources – synchronously and alternately, in the ‘acoustic pumping’ mode.
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Efficiency and Safety of Prospecting, Exploration and Development of Oil and Gas Fields in the Waters of the World Ocean
Authors V. Kerimov, V. Kosyanov and U. SerikovaSummaryImproving the efficiency and safety of exploration and development of oil and gas fields in marine areas depends on the correctness of the choice of a geological model of a promising area, site or area. The authors found that at any of the stages of oil and gas exploration it is necessary to create a digital basin model, which is a working hypothesis, within which the entire complex of accumulated geological information is systematized and analyzed from unified methodological positions. A schematic diagram of the process of studying and developing hydrocarbon resources of the continental shelf and the technological cycle of the exploration process has been studied. The results unambiguously indicate the possibility of extracting important additional geological and geophysical information about heterogeneity in the structure of the upper part of the section and the need to intensify integrated research with the development of geographic information systems to improve the safety of prospecting, exploration and development of deposits.
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Geophysical Exploration of Geological Hazards in the Eastern Gulf of Finland
Authors D. Lalomov, D. Korshunov, M. Musin and A. KolesnikovSummaryThe harbors infrastructure of the Eastern Gulf of Finland is being actively developed. In addition to the existing harbors of Vyborg, Vysotsk and the Big Port of St. Petersburg, the General Scheme of the Russian harbors complex in the Eastern Gulf of Finland includes several new ports such as Primorsk and Ust-Luga. Reconstruction of existing and construction of new harbor facilities require reliable site surveys results that will provide a comprehensive study of the engineering and geological conditions of the construction area. Nobody doubts the utility of seismoacoustic exploration during engineering geological offshore site investigations. Though, the quality of data obtained by different seismoacoustic techniques may be poor and have fail resolution and low penetration depth which depend on seismo-geological conditions. The article demonstrates the combine application of very high and ultra high resolution seismic which were useful for geophysical exploration of geological hazards in the seismo-geological conditions of the Eastern Gulf of Finland. There are widespread thixotropic muds and clays, dissected roof of the bedrock, landslide faults and shallow gas charged intervals. The main goal of this article is to present new high resolution geophysical data from that area of the Gulf of Finland which had previously lacked good data for understanding the marine geology and geological hazards mapping.
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Dangerous Gas Objects in the Waters of the World Ocean: Sea of Okhotsk
Authors V. Bogoyavlenskij, V. Kerimov, U. Serikova, R. Mustaev and O. OlhovskayaSummaryFor the first time in the Sea of Okhotsk the large volume of seismic data (more than 7000 square km) has been interpreted for near-surface gas saturated objects (like gas pockets and gas-hydrate deposits) detection and complex analysis. High gas saturation of clastic sediments has been proved, which could be dangerous for drilling. More than 200 small gas deposits (gas pockets) have been detected. Statistical analysis of their sizes has shown that 42,2 % of gas pockets are less than 1 km, 80,3 % - less than 2 km and 97,6 % - less than 4 km with the average size of a gas pocket about 1,37 km. In most cases (about 92,7 %) there are two or more gas deposits, located on different depths. Almost two thirds of gas pockets (64,3 %) situated on less than 400 m from the bottom, with maximum (23,9 %) in 200–300 m interval. The average depth of a gas deposits is 345 m. The results of the study unambiguously witnessing the possibility of extraction of important geological and geophysical information about near-surface gas saturated objects from archive seismic data.
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Complex Optimal of Magneto-Mineralogical Investigation Bottom Sediments
Authors A. Borisov and E. NurievaSummaryProposed technology includes the use of electron microscopy, x-ray microprobe analysis, the study of thermomagnetic characteristics, hysteresis properties and measurement of various types of natural and artificial magnetization. Electron microscopy technology allows direct observation of the shape, size and texture of bottom sediment particles. X-ray microprobe allows to study the elemental composition of particles. Magnetomineralogical analysis in combination with direct methods of macro and micro diagnosis allows to obtain all necessary information about the composition and origin of magnetic particles of bottom sediments.
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Estimation of the Marine Electromagnetic Systems Effectiveness for Solving Engineering Problems on the Shelf
Authors K. Roginskiy, A. Nebrat, M. Abramov and G. TrigubovichSummaryTheoretical and experimental marine research was conducted to estimate the possibilities and features for sources and receivers of electric and magnetic types (ungrounded loops and galvanic lines) used for the study of the shelf geological environment structure. For the theoretical estimation of the resolution of these electromagnetic systems geoelectric characteristics of the White and Black sea shelves were considered. Experimental studies were conducted in the waters of lake Onega and the Black sea.
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Geohazards Study International Requirements and Practice for Offshore Engineering Geological Survey
Authors A.S. Loktev, A.E. Rybalko and M.Y. TokarevSummaryGeohezards investigation is a part of engineering geological site survey and is one of the goal of the survey. Methods and techniques can be used for the investigation are the subject of local and international regulations and practices. Russian practice includes detail set of methods and scope of work of soil site investigation. when western practice means mostly methods but not scope. Different sets of surveyed geohazards in Russian and international experience is a result of variety of site soil and geological conditions. Both practices do not provide complete information on required methods, data and final results of the survey. it would be logical to split all geohazards survey in two groups: 1. shallow (limited by soil section depth of 50m and important for natural foundation stability) and 2. deep or geological.
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Features of the Technology of River Seismic Exploration
Authors V. Seleznev, A. Liseikin, A. Bryksin, S. Babushkin, A. Sysoev, E. Mosyagin and D. KrechetovSummaryAs a result of numerous seismic surveys conducted in the waters of rivers of Russia, a technology that allows working on practically any inland water bodies and solving practical problems of studying the structure of the Earth with varying accuracy and detail was created. The main feature of this technology is the use of various seismic sources operating at depths from tens of meters to half a meter, and receiving equipment, which allows recording seismic vibrations, both at great depths and on the coast. The main features of the technology of river seismic surveys, which distinguish them from land and sea, are proposed.
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Detection of Destructive Zones of the Caspian Sea According to High-Resolution Seismic Data
Authors V.V. Dolgov, D.F. Ismagilov, A.V. Khortov and S.L. MaraevSummaryHigh-resolution seismic surveys carried out in different parts of the Caspian over the past 20 years have provided fundamentally new material on the structure of the upper part of the sedimentary cover. These works allowed to identify vertical destructive zones confined to areas of development of abnormally high pressures. These destructive zones are associated with the vertical movement of fluid and its discharge from the deep strata to the upper weakly lithified quaternary deposits in the bottom part of the section, with the formation of so-called “sedimentary dykes”.
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Analysis of Optimization 2D3C Observation Systems of Multicomponent Seismic Data
Authors M.V. Aleshkin, N.A. Stepanov, G.A. Kazanin, V.V. Lantsev, S.О. Bazilevich, A.P. Zhukov and I.P. KorotkovSummarySeismic surveys in shallow water areas and in transit zones are carried out using bottom three-component recording devices due to objective restrictions on operations with towed streamers and to simultaneously receive information on exchange transverse waves for the subsequent solution of a wide range of tasks for describing reservoirs and determining their anisotropic properties. The design of such works for 3D is mainly aimed at optimizing spatial observing systems, taking into account the significant advantages of the sea source in terms of performance compared to the work on the location and movement of receiving sensors on the seabed. In such cases, optimization consists in locating the receiving arrangement on as large area as possible with increased distances between registration points (RP) and the array moves in its entirety, over the entire area of the arrangement, without overlaps along the RP. The distribution of the distances and azimuths in the CDP bins and with fold increase over the overlaps are regulated only by a multiple decrease in the distance between the SP and the SP overlaps along the explosion lines according to the principle of reciprocity.
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Problems of High-Resolution Marine Seismic Processing and Modern Techniques of Solving Them
Authors S. Buryak and S. VakuenkoSummaryRecent advances in high-resolution marine seismic acquisition requires dedicated processing techniques.
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Methodical Features of Studying the Geological Structure of the Coastal Part of the Sea of Okhotsk Based on the Integration of Continuous Aquatic Electrical Sounding and Seismoacoustics Data
Authors V.V. Glazunov, A.Y. Tatarskiy, S.B. Burlutsky, N.N. Efimova and D.A. LalomovSummaryThe work is devoted to the methodological features of conducting studies of the geological structure of the coastal water area by the method of continuous aquatic sensing using seismoacoustic data under conditions of high salinity of sea water and a significant amount of tidal fluctuations of the water level. The studies were carried out in the Sea of Okhotsk in order to obtain engineering and geological information for designing a channel to the seaport. 2D data inversion, carried out with regard to seismoacoustic studies of the water area, made it possible to increase the reliability of constructing geoelectric sections and maps.
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Aqual Survey by the Differential-Normalized Method of Electrical Prospecting (Adnme) and Continuous Dipole Electromagnetic Sounding (Ndemz) for Oil and Gas Exploration and Geological-Engineering Works
Authors A.A. Sitnikov, S.A. Ivanov, P.P. Zhugan and E.V. AgeenkovSummaryOil and gas exploration and geological-engineering works are carried out on the fresh and salt water areas by the methods of ADNME and NDEMZ. Technologically, ADNMEs are implemented as measurements in motion with a towed streamer as modifications that allow measurements at small (10–15 m) and large (up to 1000 m) depths of the sea, which significantly expands the territorial possibilities of its use. Off-shore differential-normalized method of electical-prospecting (ADNME), developed by LLC «SGRPC» company, allows mapping the distribution of the electrical resistivity of the geological environment and polarizability of rocks. The predominant prospecting indicator is a number of anomalies of the induced polarization occurring in the areas of distribution of halos of dispersion over the hydrocarbon deposits. The possibility of simultaneous obtaining information on the geoelectric and polarization properties of the medium makes it possible to significantly improve both the quality of the geological interpretation and the informative value of the results obtained, in contrast to most methods where the prediction is based only on the electrical resistivity parameter. This method has been successfully tested in diverse geoscience conditions including prospecting under halogen- and-carbon-bearing low-conductivity shield with widespread development of trap magmatism, in the areas of ancient and young platforms, continental depressions, fore deeps, in freshwater reservoirs and on the shelf of inland waters and marginal seas. The developed method NDEMZ for geological-engineering problems solving allows lateral and vertical differentiation of bottom sediments to a depth of 300–500 m in order to determine the roof and bottom of the permafrost, to highlight the area of distribution of cryopegs, areas of «gas pockets» development, changes in thickness of clay and sandy sediments.
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Parameters of Magmatic Educations in the Barents Sea According to Hydromagnetic Surveys
Authors D. Arutyunyan, I. Lygin, T. Sokolova, A. Bulychev, K. Kuznetsov and K. KrivosheyaSummaryIn the Barents Sea rather large volume of magnetoprospecting works as regional, and on detailed squares is executed. Thanks to high precision and detail of modern shooting it is possible to register surely high-frequency anomalies and, respectively, to analyze, so-called, "thin" structure of magnetic field. Authors during generalization of results of detailed sea magnetometric shooting with a total length more than 53,000 km managed to reveal regularities of distribution of anomalies of magnetic field in the Barents Sea and to draw conclusions on parameters of bedding of their sources – magmatic educations. Calculations of parameters are executed as classical methods (for example, a method of characteristic points), and by means of Poisson's veyvlet. Primary depths of the top edges of bodies no more than 2 km.
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Identification and Approaches to the Assessment of the Hazards of Faults in the Offshore During Engineering-Geological Surveys
Authors S.G. Mironyuk, A.G. Roslyakov, A.A. Ivanova and M.Y. TokarevSummaryRegulatory and scientific literature on the problem of identifying and assessment the hazards of faults has been reviewed. The experience of studying faults in the Black and the Laptev Sea is presented. Creep and seismogenic movements studied. Quantitative characteristics of creep displacements along active faults on the shelf of the northeast Black Sea, as well as amplitudes of displacements along active faults are presented. Allocation of tectonic deformation in a seismic section in the Laptev Sea according to high-resolution seismic data is an example.
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Modern Geophysical Investigations in Offshore Engineering Survey
Authors D. Chernikov, D. Naumenko and A. DemonovSummaryEngineering survey on the continental shelf are performed in order to investigate the engineering conditions of the following oil and gas facilities construction site: different types of production drilling rigs and exploratory drilling rigs. The survey has to provide the integrated investigations of engineering conditions of areas and sites for designed construction, including relief, geological structure, seismotectonic, geomorphologic and hydrogeological conditions, soil constitution, composition, properties and temperature, presence of geological processes and events, in order to obtain the necessary materials for preliminary design and project documentation justification for the oil and gas field facilities and engineering protection.
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Gas Saturation of Shallow Deposits of the Arctic and Subarctic Seas
Authors V.I. Bogoyavlensky, G.S. Kazanin and A.V. KishankovSummaryThe research is devoted to studying shallow gas potential of three northern offshore areas: the Laptev Sea, the Bering Sea and the Sea of Okhotsk. The research involved interpretation of a number of regional CDP seismic sections, with total length of approximately 14 thousands km. Numerous potential gas-saturated objects were revealed and studied. Statistical review of their distribution in the upper part of sedimentary cover was made. In 12 seismic sections, BSR horizons were revealed, most probably connected with the base of gas hydrates stability zone.
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Integrated Use of Satellite Geodetic Equipment and Multibeam Echo Sounder to Ensure High Accuracy of Seabed Imaging
Authors S. Korchak, A. Vlasov, I. Savintsev and L. StorozhenkoSummaryThe article is devoted to the currently urgent problem of the need to improve the accuracy of hydrographic surveys in the shallow parts of the shelf in order to build facilities of various scale levels. Considerable attention is paid to the method of conducting a bottom relief survey and the possibility of sharing for this mobile hydrographic and high-precision geodetic equipment. The problem of processing the data obtained during echo-sounding and their integration with geodetic survey data of the coastal area is described in detail. The results of the application of the described method in the waters of the Sea of Okhotsk are given. On the basis of the conducted research, the shortcomings and main advantages of hydrographic surveying by a multibeam echo sounder in combination with satellite geodetic equipment were revealed.
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The Russian Market of Rovs Under the Pressure of Sanctions: Problems and Solutions
Authors A.A. Shmatkov, A.G. Shmatkov and O. SergeychikovSummaryDevelopment of the Russian market of commercial surveys with use of ROV started in the mid-2000s. However, until recently domestic ROVs are still not abundant on the market, due to the presence of foreign commercially successful ROVs, attractive to the Russian service companies. First of all it was related to the fact that scientific and production companies in Russia were constructing prototypes of ROVs of observation class, while for the majority of underwater technical operations the working class or observation class with payload option ROVs are required. In connection with the introduction of the Western sanctions against Russian offshore projects related to the exploration and production of hydrocarbons since 2015, many foreign manufacturers of ROVs have to give up collaboration with Russian customers, even in providing technical support for the purchased equipment. In this regard, import substitution is vital in the sphere of construction and operation of ROVs of all classes.
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Application of the Method of Ion-Selective Electrodes in Exploration Work on the Sea Shelf
Authors M.M. Saitgaleev, N.P. Senchina and J.A. SokolovaSummaryThe paper provides information on the application of the method of ion-selective electrodes in geological exploration on the sea shelf. Currently, much attention is paid to the search for hydrocarbons in marine areas. In this regard, the authors propose a measurement method with paired, spaced electrodes of the "same name" (Cu-Cu), similar to the method of measuring the EP gradient (natural electric field). Ion-selective electrodes are able to respond to the concentration (activity) of the main ions in complex solutions in the presence of other ions. The paper presents the main problems of using this method, found a number of solutions associated with these restrictions and described further prospects for the development of this method.
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Results of the Preliminary Analysis of Gravimetric Materials of the Grace Satellite Mission on the North-East Sector of the Pacific Ocean
Authors I.V. Lygin and N.S. TkachenkoSummaryBased on the analysis of satellite gravimetric mission materials processed by the method of multichannel singular spectral method, the method of frequency analysis of three-dimensional distribution of gravitational field anomalies is developed. According to the results of the application of the method to the gravitational anomalies of the North-Eastern sector of the Pacific ocean, two areas of the most intense low-frequency variations of the gravitational field are identified, the sources of which are due to the neotectonic redistribution of masses in the Eastern end of the Aleutian arc and the Central zone of the San Andreas fault.
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Complex Geophysical Survey of the Phanagoria Water Area: Advanced Techniques
Authors S. Olkhovskiy, A. Shmatkov and A. ShmatkovaSummaryPhanagoria is the largest ancient Greek city within the territory of Russia. It founded in the 6th century BC on the shore of the modern Taman Gulf. By the 1st cent. AD the first harbor and the coastal part of Phanagoria were flooded by the transgression of the Black Sea level. A new pier was built in the 3rd cent. AD, but after 5 centuries it was flooded too. Now all the flooded structures are covered by sandy-silty sediments and can be studied either by underwater excavations or using geophysical methods. Since 2011 magnetic and seismic surveys have been conducted near the offshore site of Phanagoria having an area of more than 15 hectares. As a result of these surveys, a number of interesting features were discovered. The majority of the study area in shallow water (water depth less than 1.5 m) remains poorly studied due to technical restrictions of the applied techniques and equipment. Integration of different techniques allows to explore the survey area of archaeological excavations in greater detail in view of the limitations of each method. The tests of 3D SBP system Sleipnir showed that the results of 3D ultrahigh resolution seismic survey can be used for solving archeological tasks.
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Overhauser Four-Channel 3D Gradiometer and Its Application for Scanning the Underwater Gas Pipeline
Authors E. Narkhov, A. Shirokov, A. Sergeev, A. Fedorov, D. Milukov, V. Sapunov, A. Denisov, S. Kiselev, V. Savelev, L. Muravyov and A. IvanenkoSummaryThe paper deals with the issues of remote determination of the spatial position of buried pipelines with the help of magnetic survey. This method is economical and does not affect the environment. To achieve the required accuracy of determining the position of the pipelines, it is proposed to use a full gradient multichannel magnetiс system consisting of four Overhauser magnetometers SeaPOS combined with a receiver of a high-precision differential navigation system. Such a configuration of the system makes it possible to accurately determine in space the position of local magnetic anomalies created by pipelines and eliminates the need to take into account the temporal component of the earth’s magnetic field (which isespecially important for the Arctic) by working with spatial field gradients. The problems of the theory of the survey method and technique are considered, algorithms for data processing are proposed and implemented with the aim of solving the problem of high-precision mapping of local magnetic anomalies created by pipelines and solving the inverse magnetiс problem by determining the position and power of the sources of these anomalies.
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Engineering Survey for Drilling Rigs in the Arctic Seas
Authors I. Marchenko, D. Chernikov and N. ParamonovSummaryOil, gas and gas condensate fields in the Arctic shelf areas of the Russian Federation have become one of the most upcoming approaches in the offshore oil and gas fields’ development. At present integrated engineering surveys are actively performed at the fields in the Barents and Kara Seas. Lately a wide range of engineering works has been performed on prospecting and exploratory wells sites.Engineering surveys enable to obtain the fullest data for the upper part of geological profile and provide necessary data for safety positioning of drilling rigs. The data obtained from the stated survey is used for optimal location selection for drilling rig positioning and for the necessary calculations. The use of geophysical and geotechnical methods provide the effective solution for the stated geological challenge and ensures the obtaining of sufficient information regarding soil composition, properties and bedding conditions. The appliance of high quality geological profile data and the use of different calculation methods and standards make possible the performance of necessary foundation soils assessment and comparison of the calculation results, which consequently provides the safety positioning of a drilling rig.
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Deep Sea Near Bottom Gravity and Magnetic Acquisition with Autonomous Underwater Vehicles
Authors I.V. Lygin, V.A. Lygin and T.I. LyginaSummaryThe current stage is characterized by high activity of the world community in the field of research of deep-water oil and gas basins and new promising types of solid minerals. A promising direction in terms of improving the efficiency and reliability of exploration results on hydrocarbon and solid mineralsof the world ocean is the use of Autonomous unmanned underwater vehicles, which allow for detailed large-scale bottom surveys, quickly and efficiently. The required component of the Autonomous underwater complex is the means of measuring the components of the magnetic and gravitational fields. The report provides an overview of modern foreign and domestic technologies in the field of underwater deep-sea gravimetric and magnetometric surveys, analyzes the results of such works and formulates a range of exploration tasks that are promising for their application.
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Main Stages of Geological Development of the Eastern Gulf of Finland (Baltic Sea) in the Late Pleistocene - Holocene Based on the Analysis of Archive Sub-Bottom Profiling Data
Authors L. Budanov, A. Sergeev, D. Ryabchuk, V. Zhamoida and I. NeevinSummaryAnalysis of archive sub-bottom profiling and geological was performed to identify and map submerged glacial and postglacial geomorphologic features and collect data pertinent to the understanding of sedimentation in postglacial basins. Interpretations of the seismic-reflection profiles and models showing the surfaces of till, and the identification of the Late Pleistocene sediment and modern bottom relief, indicate deep relative water-level fall in the Early Holocene and, most likely, several water-level fluctuations during this time.
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Some Technological Aspects of Start-Stop Electromagnetic Soundings in the Transition Zone of the Shelf
Authors A.S. Bashkeev, Y.A. Davidenko, K.V. Abornev, S.V. Bukhalov and S.V. IakovlevSummaryThe transition zone is a zone of shallow water immediately adjacent to the coastline of offshore areas, where, due to the shallow depth of the sea (less than 10–15 m.) and marine geophysics are ruther complicated; at the same time, the useage of ground-based start-stop EM sounding is impossible because of the deep water (more than 2 m). In this paper, we will consider some technological aspects of start-stop measurements in the transit zone on the example of test work in the shallow waters of the Black Sea.
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The Advantages of Using Surface Wave Tomography in the Marine Studies of the Upper Part of the Seismic Section
Authors A. Ponomarenko, V. Polovkov, D. Popov and B. KashtanSummaryThe study of the upper part of the seismic section is an important task for seismic surveys on land and sea, both in oil and gas exploration and in solving engineering problems as well as in monitoring of dangerous geological processes. Information about the structure of the upper part of the seismic section can be extracted from the analysis of surface waves that propagate in near-surface media, have a large amplitude and in many cases constitute a significant part of the recorded wave field. The most used method for surface wave acquisition and analysis is multichannel analysis of surface waves (MASW). However, it is not possible to set the remote studies: the sources and receivers should be set just under the investigated area. The method of surface-wave tomography makes it possible to carry such studies. The advantages of surface-wave tomography for engineering problems are discussed with several numerical examples. The main advantage - the method of surface wave tomography makes it possible to study various engineering and geological objects remotely. This has tremendous perspectives for land and marine seismic exploration to study the environments under closed or protected objects, pipelines, drilling platforms, etc.
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Self-Popup Node Surveying Features and Application to Arctic Shelf Investigation.
Authors D.A. Ilinskiy, O. Y. Ganzha, A. I. Elnikov and К.А. RoginskiySummaryIn this paper we outline some features of self-popup node seismic surveying and provide example of their implementation for Russian Arctic shelf studies.
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Modern Methods and Equipment for Hydroacoustic High- Precision Surveys of the Sea Bottom
Authors L. Merklin, A. Pleshkov, A. Sknarya and S. TarasovSummaryThe effectiveness of modern methods of hydroacoustics in the survey works of marine geology, can be significantly increased in construction of equipment on the principles of phase processing and using of complex broadband signals. We have developed modifications of side-scan sonars, which can significantly increase the information content, increase the resolution and improve the accuracy of the coordinates. One of them is the sidescan interferometric sonar. Additional receiving channels with additional receiving arrays in the vertical plane are included in the side-scan sonar to measure the bottom relief. These receiving channels allow you to get an additional parameter – the angle of arrival of the echo signal, which calculates the depth and horizontal range. The side-scan interferometric sonar is rightfully a competitor of a multi-beam echo sounder with a much larger field of view. Another development is the wideband side-scan sonar. The use of broadband technologies has made it possible to obtain a qualitatively new instrument for the study of the bottom of the world ocean with high resolution. Due to the construction of equipment on the principles of using complex ultra-wideband signals (such as frequency modulated or chaotic), the efficiency of modern hydroacoustic methods in the survey works are increases.
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The Role of Nonlinear Hydroacoustics in Marine Technologies of the Sea Shelf Research and Development
Authors L. Merklin, A. Pleshkov, P. Pivnev, A. Sknarya and S. TarasovSummaryThe main feature of parametric sonars, the principle of which is based on the nonlinear interaction of acoustic waves, is the constancy of the beam pattern in a wide low-frequency frequency range. The General principal advantage of parametric narrow-beam profilers is that at the same volume of the medium within a narrow beam, at all frequencies, is "voiced", which allows comparing the results of measurements at different frequencies. Two types of parametric profilers are presented for the survey of the structure of the sedimentary layer of the seabed. This is a low-frequency parametric seismic Profiler operating in the range of difference frequencies from 0.5 to 5 kHz at an average pump frequency of 30 kHz. Depending on the type of bottom soil, the depth of penetration can reach 500 meters. The second device is an original equipment, the so-called parametric side-scan sonar. Its main technical characteristics: the range of difference frequencies is 7–20 kHz, with an average pumping frequency of 145 kHz. The depth of penetration, depending on the type of soil, is 50 meters with a resolution of 10 cm when using the LFM signal. The use of parametric profilers with complex signals makes it possible to study the structure of the upper part of the sedimentary cover with high accuracy and to evaluate the physical properties of marine sediments.
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The Latest Trends in Near-Surface Marine Seismic Survey (2D, 3D)
Authors E.A. Biriukov, M.U. Tokarev and V.V. IvanovaSummaryIn present time due to the active development of the Arctic shelf increasing safety of construction and exploitation of offshore production complex is one of current direction of development in oil and gas industry. For efficient solution of problems in engineering-geological researches, defining and characterization of geohazards in particular, it is necessary to obtain only high resolution and very high resolution 2D, 3D seismic .
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Identification of Geological Facilities Under the Conditions of Gas Saturation of the Upper Part of the Profile During Engineering Site Investigations
Authors A. Kozlova, A. Luchnikov and A. BiryulinSummaryData received by seismic reflection profiling show that in the Gulf of Ob starting from the depth of 1–2 meters under mudline almost everywhere sediments saturated by non-associated gas are presented. The presence of nonassociated gas does not allow exploring deeper levels of sedimentation masses. Usage of thorough interpretation of magnetic response allowed to locate the area of tectonic tension of earth material, which was apparently the fault zone complicated with intrusive formations. Due to the lack of a priory information and possibility to make a comprehensive assessment of geology and geophysics data, the 2d modeling was impossible on the present stage. A case study of computational methods shows that the depth of tectonic dislocation area cannot be more than 250 meters.
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The Use of Splitmultiseis Seismic Imaging Technology to Study Gas-Saturated Sediments of the White Sea
Authors A. Potemka, E. Birukov, M. Tokarev, A. Pirogova, A. Starovoitov and E. PoludetkinaSummaryThe active development of the Arctic in recent years has led to an increase in demand for high-quality engineering and geophysical surveys. One of the key areas of engineering surveys on the shelf is the search for geological hazards, such as landslide processes, fault fractures, high gas saturation zones, areas of focused fluid discharge, etc. The report is devoted to the development of modular technology SplitMultiSeis for conducting high-resolution seismic exploration in shallow water areas and the experience of its application for studying gas-rich sediments at the White Sea.
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Geophysical Approach to the Geohazard Classification in Marine Engineering and Geological Surveys
Authors M.J. Tokarev, A.G. Roslyakov and Y.E. TerehinaSummaryAn utilitarian scheme for the separation of geological hazards, regardless of their nature, is proposed. It is based on the interval study of the section, determined by the type of the planned construction. At the same time, each such interval should be studied using a specific set of methods and, thus, it is connected not only to the type of construction, but also to the approach of methods of geophysical research.
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Phase-Shift Signal Design for Simultaneous Sourcing in Vibroseis Survey
Authors A. Tarasov, A. Shuvalov, V. Ignatev, A. Konkov, B. Kashtan and A. OshkinSummaryThe simultaneous source technique allows one to improve efficiency and quality of seismic acquisition. The principle of this method is to use several sources located at an arbitrary distance from the observation system and recorded simultaneously within the write cycle. Vibroseismic method, in contrast to the pulse method, allows separating data from several sources at the stage of correlative processing of vibrograms. To achieve this, it becomes necessary that signals from several sources have a low level of cross-correlation. For this purpose, socalled pseudorandom signals and pseudorandom sequences are used in many ways. In order to construct quasiorthogonal signals, we propose a method based on the solution of the optimization problem. The signals obtained by minimizing the goal function have a low level of cross-correlation and autocorrelation functions.
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Glacigenic Factors in the Soil Foundations of Offshore Structures Formation at the South-Eastern Baltic Shelf
Authors V.P. Lisin, B.F. Romanyuk and R.N. SeredenkoSummaryThe influence of the glacial masses of the Quaternary glaciations on the structure and the physical properties of the upper part of the ground layer, which serves as the basis for the offshore structures and linear infrastructure facilities of the offshore oil fields on the shelf of the South-Eastern Baltic, is considered. The complex of hydrographic and geophysical works performed at the first stages of engineering surveys allows to evaluate various factors of the dynamic impact of continental glaciers on the formation of the surface of strong bearing soils, as well as weakened zones due to glacio-isostatic deformations and the accumulation of weak in strength relation soils in glacial lakes and channels.
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Identification of Potentially Hazardous Areas for Offshore Structures on the Southern Caspian Shelf by Multi-Frequency Seismic-Acoustic Methods
By V.P. LisinSummaryThe possibilities of identifying hazardous for geotechnical work and for the construction of offshore structures zones of tectonic dislocations and associated with them shallow gas accumulations using sonar survey, seismoacoustic profiling in a wide frequency range and 3D seismic prospecting are considered.
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The Results of Electrical Survey on Lake Onega
Authors A. Bobachev and M. AleshinSummaryIt is shown electrical resistivity tomography data interpretation on Onega Lake. The bottom depth is about 25 m. We add works with bottom cable to continues survey on lake surface. Joint interpretation resistivity and seismic survey is shown.
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Selection of Gas-Saturated and Permafrost Sediments in the Laptev Sea According to Seismic Data
Authors A. Roslyakov, M. Tokarev and I. SemiletovSummaryStudies have shown that in the study area are widely distributed gas-saturated and frozen rocks, occurring at small depths from the bottom - from the first meters to tens of meters.
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Proton Overhauser Magnetometers: Theory and Experimental Study of the Ship Magnetic Influence
Authors V. Sapunov, A. Denisov, V. Savelev, O. Denisova, S. Yaroshenko, L. Muravyev, E. Narkhov, A. Sergeev, A. Fedorov and V. GladyshSummaryThe report presents marine Overhauser magnetometers developed and produced in the Quantum Magnetometry Lab of the Ural Federal University, Russia. The general design of Overhauser magnetometers and working radical properties are considered. In particular, we discuss a radical used in our land-based and marine magnetometers distinguished by increased stability and special properties of the Heisenberg exchange allowing for signal amplification. We present several examples of actual geophysical measurements using SeaPOS-1 and SeaPOS-2 magnetometers. We consider in details an influence of the vessel magnetic moment on the measurement results. In the experiment the ship passed at different azimuths and distances to the magnetometer placed inside the nonmagnetic anchored rubber boat. Theoretical and experimental results showed that due to interaction of magnetic fields the vessel impact on the measurement can be significant.
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