Laminae characteristics of gas-bearing shale fine-grained sediment of the Silurian Longmaxi Formation of Well Wuxi 2 in Sichuan Basin, SW China

• 作者: DONG Dazhong LIANG Pingping LU Bin QIU Zhen SHI Zhensheng ZHANG Mengqi
• 来源期刊: 石油勘探与开发:英文版
• 学科: 地球科学
• 关键词: Sichuan Basin Longmaxi Formation FINE-GRAINED SEDIMENT SHALE GAS lamina WELL WUXI 2
• 年，卷（期）: 2018,（2）
• 页码范围: 358-368
• 页数: 11页
• 分类号: P618.13

摘要

Based on various test data, the composition, texture, structure and lamina types of gas-bearing shale were determined based on Well Wuxi 2 of the Silurian Longmaxi Formation in the Sichuan Basin. Four types of lamina, namely organic-rich lamina, organic-bearing lamina, clay lamina and silty lamina, are developed in the Longmaxi Formation of Well Wuxi 2, and they form 2 kinds of lamina set and 5 kinds of beds. Because of increasing supply of terrigenous clasts and enhancing hydrodynamics and associated oxygen levels, the contents of TOC and brittle mineral reduce and content of clay mineral increases gradually as the depth becomes shallow. Organic-rich lamina, organic-rich + organic-bearing lamina set and organic-rich bed dominate the small layers 1-3 of Member 1 of the Longmaxi Formation, suggesting anoxic and weak hydraulic depositional setting. Organic-rich lamina, along with organic-bearing lamina and silty lamina, appear in small layer 4, suggesting increased oxygenated and hydraulic level. Small layers 1-3 are the best interval and drilling target of shale gas exploration and development.