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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
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Marine Technologies 2019, Apr 2019, Volume 2019, p.1 - 11
Abstract
Oil 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.