特种油气藏2024，Vol.31Issue(4)：64-70,7.DOI:10.3969/j.issn.1006-6535.2024.04.008
断面有效正应力对断层侧向封闭能力的控制作用
Control of Effective Normal Stress on Fault Lateral Sealing Capacity
摘要
Abstract
The lateral sealing of small displacement faults determines the capacity of fault traps to accumulate oil and gas.With the development of oil and gas exploration technology theories,the role of small displacement faults,which were once overlooked,is becoming increasingly prominent in the process of oil and gas exploration and devel-opment.To clarify the internal structural characteristics of small displacement faults and the influence on the lateral sealing of faults,a self-developed high-pressure and low-speed circular shear device was applied.Taking the ef-fective normal stress of the cross-section as a variable,it conducts circular shear physical simulation experiments on high porosity pure sandstone to analyze effective normal stress on the lateral sealing of faults.The results show that the fracture mechanism is mainly characterized by fragmentation in high porosity and pure sandstone,forming typi-cal fragmented fault rocks.The significant decrease in permeability is the fundamental reason for the lateral sealing of the joint section of sandstone in the same formation.Under the condition that other factors remain unchanged,the larger the effective normal stress of the cross-section,the greater the degree of fragmentation of the fault rock,and the smaller the particle diameter and porosity;the fracture of rock particles and the filling of detrital matrix lead to a significant decrease in porosity and permeability of the fracture zone.The effective normal stress of the fault sec-tion is the main controlling factor of the lateral sealing capacity of the small displacement fault.Small displacement faults have the potential of oil and gas accumulating.The study results have guiding significance for the exploration and development of fault-block oil and gas reservoirs in rift basins.关键词
小位移断层/断面有效正应力/环形剪切/渗透性/侧向封闭性/渤海Key words
small displacement fault/effective normal stress/circular shear/permeability/lateral sealing/Bohai Sea分类
石油、天然气工程引用本文复制引用
严念斌,王海学,侯嘉怡,姜明明,宋宪强..断面有效正应力对断层侧向封闭能力的控制作用[J].特种油气藏,2024,31(4):64-70,7.基金项目
国家自然科学基金"断层破坏盖层机理及封闭性定量评价"(41972157)、"基于环形剪切实验的高孔隙砂岩碎裂变形带主控因素与封闭能力研究"(42302146) （41972157）
黑龙江省普通本科高等学校青年创新人才项目"断层在泥岩盖层段变形机制及垂向封闭有效性定量评价"(UNPYSCT-2020142) （UNPYSCT-2020142）
