O. V. Chikisheva, Yu. V. Grechko, D. A. Mitrofanov, I. N. Zhizhimontov, M. A. Basyrov, I. A. Zyryanova

Increasing the success of geological exploration and prospecting work with the AINK-PL complex, based on the Achimov deposits (northern West Siberia)

Abstract. The paper describes experience in using pulsed neutron logging equipment (AINK-PL device) to solve prospecting and exploration work tasks, based on two wells exposing the Achimov complex reservoir rocks in a field located in the Yenisei-Khatanga structural-facies area. The domestic AINK-PL complex has been effectively implemented at the Rosneft Oil Company’s facilities since 2023. The AINK-PL processing methodology in RN-Geology Research Development quantitatively determines a detailed chemical composition of rocks (16 elements), macroscopic capture cross-section, and hydrogen content (neutron porosity). In the article, chemical elements obtained with an impulse neutron-gamma spectrometry method may serve as indicators for determining the typical mineral composition of a section, with the core data missing. There is analyzed the influence of the impulse neutron-gamma spectrometry method and gamma-gamma density logging on the volumetric component model results. Sequential exclusion of these methods from input data results in an underestimation of rock-forming minerals and decrease in the sandstone proportion (clay content increase) in the total rock volume. Exclusion of the gamma-gamma density logging from input log data leads to a porosity ratio decrease, as compared to core data (~2 % absolute). The obtained results prove efficiency of the optimal logging complex for subsequent exploratory and production drilling.

Keywords: Achimov deposits, pulsed neutron logging equipment, mineral composition of rocks, impulse neutron-gamma spectrometry method, volumetric component model, complex reservoir rocks