鄂尔多斯盆地长北区块山西组天然裂缝特征及其对天然气产能的影响

Natural Fracture Characteristics of Shanxi Formation in Changbei Block of Ordos Basin and Its Influence on Natural Gas Production Capacity

摘要: 地面露头、钻井岩芯、测井资料和铸体薄片鉴定资料表明，鄂尔多斯盆地内的各类脆性地层中，普遍发育未充填的雁行状或“X”共轭剪切节理、裂缝、微裂缝和局部小型治理直立断裂。因挤压、剪切等构造应力产生的节理(裂缝)以及沿这些裂缝派生的溶蚀作用，无疑成为低孔、低渗背景下的致密储层中油气相对富集高产的髙孔、髙渗带。本文拟从地面露头调查、FMI测井和少量钻井岩芯、铸体薄片中的裂缝资料入手，分析长北区块山2储层中的裂缝成因、发育特征、分布规律及其对天然气产能的影响。

Abstract: The ground’s outcrop, drilling core, logging data and casting thin section identification data show that there are generally unfilled en echelon or “X” conjugate shear joints, fractures, micro fractures and local small vertical governance fractures in all kinds of brittle strata in Ordos Basin. The joints (fractures) caused by structural stresses such as compression and shear, as well as the corrosion induced by these fractures, undoubtedly become the high porosity and high permeability zones with relatively high oil and gas enrichment and high yield in tight reservoirs under the background of low porosity and low permeability. Based on the surface outcrop survey, FMI logging and fracture data from a small number of drilling cores and casting thin sections, this paper intends to analyze the genesis, development characteristics, distribution rules of fractures in Shan2 reservoir in Changbei block and its influence on natural gas production.