低孔隙岩石中断裂带内部结构及与油气成藏  

Internal structure of fault zone and oil/gas reservior in low-porosity rock

作　　者：付晓飞[1,2] 尚小钰[1,2] 孟令东[1,2] 

机构地区：[1]东北石油大学CNPC断裂控藏实验室,黑龙江大庆163318 [2]东北石油大学非常规油气成藏与开发省部共建国家重点实验室培育基地,黑龙江大庆163318

出　　处：《中南大学学报（自然科学版）》2013年第6期2428-2438,共11页Journal of Central South University:Science and Technology

基　　金：教育部科学技术研究重点项目(212041);黑龙江省普通高等学校新世纪优秀人才培养计划项目(1251-NCET-015);中石油中青年创新基金资助项目(2012-5006-0107)

摘　　要：通过大量的野外露头资料,研究低-非孔隙性岩石内断裂变形机制及形成断裂带内部结构,分析断裂对非常规油气富集的控制作用。研究结果表明:低-非孔隙性岩石内断裂变形机制为破裂作用、碎裂作用和碎裂流作用,分别形成初角砾岩、角砾岩和碎裂岩以及超碎裂岩,前3类断层岩渗透性相对较高,多为流体运移的通道。不同岩性地层内形成的断裂带结构有共性也有差异,共同特征是:伴随位移增加,断裂带逐渐从"一元"结构向"二元"结构发展,一旦大规模断层泥形成,变形集中在断层核上,破碎带宽度不再明显增加。不同的是演化模式的差异,碳酸盐岩压溶作用明显,伴随大量压溶缝形成和生长连接,最终演化成断裂。火山岩特别是凝灰岩中,开始发生断裂变形不形成破碎带,而是先形成断层核。超固结泥岩形成的断裂带开始渗透性增强,伴随断层泥产生,渗透率又会接近母岩。这种差异可能造成断层封闭模式演化及油气富集规律的差异。仅发育破碎带小规模断层、无内聚力的断层角砾岩、碎裂岩以及具有连续断层核的破碎带为典型的高渗透性断层,对非常规储层油气充注起到重要的作用。断层核渗透性决定断层封闭类型及油气富集模式,高渗透性断层核本身不具有封闭能力,主要靠岩性对接封闭,油气通常富集在区域性盖层之下且主要富集在断裂的下盘。低渗透断层核具有很强的封闭能力,油气在两盘均可以富集。破碎带由于大量裂缝发育,成为非常规油气富集的"甜点"区,有些致密气和页岩气富集区沿着断层呈条带状分布。Based on a lot of outcrop data, the fault deformation mechanism and fault zone internal structure of low-non porosity rocks were studied, and the control of fault on the unconventional oil and gas accumulation was analyzed. The results show that fault deformation mechanism of low-non porosity rocks are fracturing, cataclasis and cataclastic flow effect, which respectively forms the beginning of breccia, breccia, cataclasite, and ultra-cataclasite. The former three types are relatively high in fault rocks permeability, and are the channels of fluid migration. The fault zone structure formed in different lithostratigraphies has both similarity and difference. The common feature is that fault zone gradually develops from ＂one dimensional＂ structure to ＂two-component＂ structure with increased displacement. Once the large-scale fault gouge forms, the deformation concentrated on fault core and damage zone width doesn＇t increased significantly. The difference is in development pattern. The pressure solution of carbonate rock is apparent, andaccompanied by a lot of pressure solution seam formation and growth connection, ultimately evolves into the fault. The volcanic rock, especially tuff, doesn＇t form damage zone at the beginning of fault deformation, but first forms fault core. The fault zone formed in overconsolidated mudstone. The permeability increases at first, and with the growth of fault gouge, the permeability becomes close to that of the parent rock again. This difference may cause the disparity in the evolution of fault sealing model and the rule of hydrocarbon enrichment. Only developed damage zone of the small-scale fault, non-cohesive thult breccia, cataclasite and damage zone with the continuous fault core are the features of high permeability fault, which plays an important role in oil and gas filling in the unconventional reservoir. The permeability of fault core determines fault sealing type and hydrocarbon accumulation pattern, and high-permeability fault core itself doesn＇t have the seal

关 键 词：低-非孔隙性岩石 断裂变形 结构 非常规储层 油气运聚成藏 

分 类 号：TE122.3[石油与天然气工程—油气勘探]