Distribution and hydrocarbon accumulation characteristics of Maokou Formation karst reservoirs in southwestern Sichuan Basin

doi:10.3969/j.issn.1006-6535.2025.04.006

Abstract

Abstract: To address the unclear understanding of the distribution and hydrocarbon accumulation characteristics of Maokou Formation karst reservoirs in southwestern Sichuan Basin,this study integrated geological, drilling, logging, and 3 D seismic data, classified the karst reservoirs, selected seismic attributes for distribution prediction, and analyzed the hydrocarbon accumulation relationships of different karst reservoir types. The study shows that the study area, located in a favorable paleogeomorphic unit, features four types of karst reservoirs developed: top karst, interbed karst, fault-associated karst, and karst collapse. Seismic texture entropy attributes effectively characterize interbed karst bodies and karst collapse. The hydrocarbon accumulation mode of the study area is "self-sourced and self-stored, sourced in lower part and stored in upper part, with efficient transport via faults and fractures." The distribution of Maokou Formation gas reservoirs is jointly controlled by paleogeomorphology, karst reservoir distribution, and fault and fracture systems. The research findings provide crucial support for further Maokou Formation exploration in the area.

Key words: paleogeomorphology, karst reservoir types, entropy attributes, hydrocarbon accumulation characteristics, Maokou Formation, southwestern Sichuan Basin

CLC Number:

TE122.2

LI Suhua, JIA Huofu, LU Qijun, LI Rong, SU Chengpeng, ZHU Lan. Distribution and hydrocarbon accumulation characteristics of Maokou Formation karst reservoirs in southwestern Sichuan Basin[J]. Special Oil & Gas Reservoirs, 2025, 32(4): 50-57.

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