APPLICATION OF THE METHOD OF STATISTICAL-CORRELATION INTERPRETATION OF GWS DATA IN THE SAMOTLOR FIELD

Abstract

Link for citation: Melnik I.A., Zhdanova Yu.Yu., Sidorenko N.S. Application of the method of statistical-correlation interpretation of GWS data in the Samotlor field. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 104-114. In Rus. Relevance. The problem associated with low-resistance reservoirs in the fields of Western Siberia has been relevant since the end of the last century. According to the materials of geophysical studies of wells, productive low-resistance reservoirs are often interpreted as water-saturated, as a result of which they are not used in the further operation of the well. The study is caused by the possibility of detecting previously missed low-resistance productive sand reservoirs from the archives of geophysical well surveys of the old fund and from missing core materials. The main aim: illustration of applying the method of statistical correlation interpretation of geophysical well surveys materials to search for missed deposits at the Samotlor oil and gas field (Khanty-Mansiysk Autonomous Okrug). Objects: productive Jurassic and Cretaceous sand deposits of the Samotlor fields. Methods: statistical interpretation of the geophysical well surveys data to identify the intensities of superimposed epigenetic processes of kaolinitization, carbonatization, pyritization, pelitization and missed low-resistance HC-saturated reservoirs. Results. The application of the method of statistical-correlation interpretation of the material’s geophysical studies of wells in the sand reservoirs of the Samotlor field made it possible to determine the indicators of oil and gas saturation and identify promising intervals with reduced electrical resistivity. The boundary values of the studied indicator are determined when identifying promising zones. Comparison of the values of the low-resistance parameter with the saturation character of the tested collectors (previously unknown to us) allowed us to determine the success rate (Csuc.=87 %) of this indicator application. The calculated values of statistical intensities of secondary processes made it possible to identify the reasons for the decrease in electrical resistances of the studied layers and to determine the incremented resistance due to pyritization, pelitization and the formation of increased surface electrical conductivity of clay cement of sandy rock.

Keywords

• superimposed epigenetic process
• secondary kaolinitization
• secondary pyritization
• low resistivity reservoir
• hydrocarbons
• specific electric resistivity