The article presents the results of increasing the efficiency of geological exploration at one of the key clusters of Rosneft Oil Company in Eastern Siberia. The increase in the efficiency of work is ensured due to the integration of field geophysical methods - geoelectric prospecting and vintage 2D seismic data. This allowed not only to significantly reduce the geological risks associated with the unique geology of the region, but also to reduce the cost of exploration.
The paper presents a brief description of the geological structure of the Yurubchen-Tokhomo oil and gas accumulation zone. As well as, the paper describes the main difficulties in separating Riphean sediments from the basement rocks based on vintage 2D seismic data. It is proposed to combine the seismic CDP method and the TEM method to separate the Riphean terrigenous-carbonate sediments from the basement granitoids. In addition, the paper describes the theoretical prerequisites of the TEM method using resistivity for the separation of the Riphean sedimentary rocks from the intrusive basement rocks. The integration of the methods are justified by using numerical modeling and the results of the analysis of well logging data. An approach to the complex analysis of the two methods at the qualitative level is demonstrated. This approach allows to greatly decrease the main limitations of each of the methods, thereby increasing the reliability of the data interpretation results, the success of subsequent exploration and reducing the risks of drilling into the unproductive basement rocks. The resulting geological model is fully consistent with the drilling results, which could not be achieved by only using the vintage 2D seismic data. A quantitative assessment of the change in the probability of geological success and an assessment of the value of information (VOI) obtained as a result of integration were carried out.
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