COMPARATIVE PETROPHYSICAL CHARACTERISTIC OF THE CUTS OF THE GERASIMOVSKOE AND KRAPIVINSKOE FIELDS (IN RELATION TO PETROLEUM POTENTIAL OF PRE-JURASSIC DEPOSITS)

Abstract

The relevance of the research is caused by the need to reproduce the raw material base of hydrocarbons in the southeast of Western Siberia due to prospecting and exploration of deposits associated with pre-Jurassic deposits. The aim of the research is to determine the criteria for forecasting and prospecting Paleozoic hydrocarbon deposits based on a study of geophysical differences in the sections of the Jurassic field sediment with both Paleozoic deposit of oil and fields with nothing but Jurassic oil deposit. The objects of the research are the sections of deep wells of the Gerasimovskoe oil and gas condensate field with the main reserves in the reservoir M – in permeable intervals of crust weathering of Paleozoic deposits and wells of the Krapivinskoe oilfield, which industrial oil bearing capacity is associated with terrigenous sediments of the Jurassic productive horizon J1. Methods: statistical analysis of petrophysical parameters of reservoirs according to well logging data, assessment of the lithological composition of reservoirs by petrophysical criterion, comparative assessment of the geophysical characteristics of the Bazhenov suite of the Gerasimovskoe and Krapivinskoe fields. Results. On the example of geophysical characteristics of sections of 29 deep wells of the Gerasimovskoe field and 34 wells of the Krapivinskoe field, it is shown that Paleozoic deposits have a unique «reflection» in the geological and geophysical parameters of the overlying Mesozoic–Cenozoic sedimentary section. This uniqueness is expressed by significantly higher values ​​of electrical resistivity and carbonatization of the intervals of Jurassic sediments, as well as the distinctive characteristic of the geophysical parameters of the interval of the Bazhenov suite. To further argue the uniqueness of the «reflection» of Paleozoic deposits in the geophysical parameters of overlying sediments, as a criterion for predicting and searching for Paleozoic hydrocarbon deposits, it is proposed to conduct similar studies at several fields of both Gerasimov and Krapivinskoe types.

Keywords

• hydrocarbon deposits of pre-jurassic deposits
• geophysical characteristics of the overlying sedimentary section
• unique geophysical «reflection» of the paleozoic deposits
• criterion for forecasting the oil and gas potential of paleozoic
• south-east western siberia