Characteristics, Controlling Factors and Reservoir Quality Implications of Inner Fracture Zones in Buried Hills of Archean Covered Metamorphic Rock in Block 13-2, Bozhong Depression

作者：Junjie Lu, Xuanlong Shan, Jian Yi, Huiyong Li, Peng Xu, Guoli Hao, Ang Li, Shuai Yin, Shuyue Ren, Chaoyang Liu, Yunqian Shi · 发表于：Energies · 年份：2024 · DOI：10.3390/en17061345 · 被引用次数：2 · 研究领域：Hydrocarbon exploration and reservoir analysis、Hydraulic Fracturing and Reservoir Analysis、Geological Studies and Exploration

Inner fracture zones play a decisive role in the formation of high-quality reservoirs in buried hill reservoirs in covered metamorphic rock. Based on core, sidewall core, thin section, seismic, logging and reservoir physical property data, the fracture development characteristics of the Bozhong 13-2 block buried hill reservoir are described in detail and the controlling factors and the influence on reservoir quality are discussed. The results showed: (1) three groups of tectonic fractures developed in the study area—near-EW-striking, ENE-striking and nearly N–S-striking fractures—were controlled by the early Indosinian thrusting, the late Indosinian to early Yanshanian sinistral strike-slipping and the late Yanshanian late dextral strike-slipping in the Bohai Bay Basin, respectively. The ENE- and nearly-E-W-striking fractures are the most common, and the dip angles of the fractures are mostly between 35° and 75° and thus oblique. (2) The Indosinian-early Yanshanian was the main fracture-forming period, and the dextral strike-slip action in the late Yanshanian was the key to maintaining effective fractures. Imaging logging shows that 97.87% of the fractures are effective fractures. Based on thin section observation, 14.47% of the fractures are unmodified open fractures and 80.37% of the fractures are effective fractures due to reactivation. (3) The late Yanshanian strike-slip fault transformed the deformation adjustment zone formed by the early Indosinian thrust faulting and t...