Spectrometric gamma-ray logging. Definition of productive intervals and appraisal of gas saturation in low-permeable reservoirs of Cenonian deposits in the northern part of Western Siberia

Sergey N. Men'shikov Ph.D., head of department PJSC “Gazprom”, Saint Petersburg
Sergey K. Akhmedsafin deputy head of department PJSC “Gazprom”, Saint Petersburg
Sergey A. Kirsanov Ph.D., head of department PJSC “Gazprom”, Saint Petersburg
Sergey A. Egurtsov general director IOGT LLC, Moscow
Alla F. Zaytseva Ph.D., chief specialist of section of log data complex interpretation IOGT LLC, Moscow
Yuriy V. Ivanov Ph.D., deputy general director on production — technical director IOGT LLC, Moscow
Aleksandr G. Novikov head of section of log data complex interpretation IOGT LLC, Moscow
Sergey V. Nersesov Ph.D., deputy general director — chief geologist “Gazprom dobycha Nadym” LLC
DOI: 10.24411/2076-6785-2019-10034

The results of applying new methodological approach to the integrated study of lithologic and petrophysical properties and the saturation nature of Cenonian reservoir formations by using the multi-method multiple sonde gamma-ray logging (MGRL) are presented.

MGRL capabilities are demonstrated during the study of poorly studied lower Bereyozovsk opokamorphic low-permeable reservoir beds with raw hydrocarbons that are hard to recover (RHR).

The possibilities of detailed lithological formation typing are confirmed, which significantly increases the reliability of processing and interpretation of GIS results using MGRL. The advantages of the technology for forecasting and additional exploration of raw hydrocarbon reserves are presented.



MGRL technology, which allows obtaining layer-by-layer detailed information about reservoirs (including their lithological composition, reservoir properties, nature and degree of saturation, effective oil and gas saturated thickness of the reservoir, the position of fluid contacts, etc.) can be applied successfully in wells of various structures for study of Cenonian sediments and other low-permeability reservoirs.

A positive case record of applying the new methodological approach for integrated study of lithological and petrophisycal properties and saturation nature of low permeable reservoirs is obtained by using MGRL technologies on wells of Gazprom PJSC.



The suggested methodological approach of lithological formation models interpretation allows to determine the criteria of reservoir quality discrimination and provides opportunity to conduct detailed lithological formation typing, and this significantly increases the processing reliability and interpretation of MGRL results.

Application of the suggested approach increases the accuracy and level of detail for reservoir beds definition with reserves that hard to recover, even with lack of core material.

Applying MGRL technologies for determination of all necessary volumetric data (gas saturation factor, dyke cumulative thickness etc.) reveals new additional opportunities for conducting detailed field appraisal for hydrocarbon reserves in conditions of producing wells inventory in exploited oil and gas provinces, that without killing wells and drilling additional wells fund provides a significant economic effect.

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