渝东南牛蹄塘组页岩裂缝及其分布控制因素  

Controlling factors of fracture distribution of shale in Lower Cambrian Niutitang Formation in southeast Chongqing

作　　者：岳锋[1,2,3] 焦伟伟[1,2,3] 郭淑军 

机构地区：[1]国土资源部页岩气资源勘查重点实验室(重庆地质矿产研究院),重庆400042 [2]重庆市页岩气资源与勘查工程技术研究中心(重庆地质矿产研究院),重庆400042 [3]油气资源与探测国家重点实验室重庆页岩气研究中心,重庆400042 [4]中国石油天然气勘探开发公司,北京100034

出　　处：《煤田地质与勘探》2015年第6期39-44,共6页Coal Geology & Exploration

基　　金：国家高技术研究发展计划(863计划)项目(2013AA064503);重庆市自然科学基金重点项目(cstc2012jj B90007)

摘　　要：为总结渝东南下寒武统牛蹄塘组页岩裂缝特征及其分布的主要控制因素,通过页岩露头、岩心和薄片裂缝观察、描述,探讨了页岩裂缝的成因类型、分布特征及裂缝分布与脆性矿物含量、页岩层厚、岩石力学性质、构造、页理发育和有机质含量及热演化程度的关系。结果表明,牛蹄塘组页岩裂缝从成因上分为构造裂缝、成岩裂缝及异常高压裂缝。牛蹄塘组页岩主要发育近东EW向、NE向和近SN向三组构造裂缝,近EW向一组裂缝最发育。裂缝以高角度剪切裂缝为主,规模较小,储集能力一般,主要起渗流作用。脆性矿物含量是控制页岩裂缝形成和分布的主要内因,外因主要是岩层厚度、岩石力学性质、构造应力与构造部位,页理发育影响页理缝及低角度滑脱裂缝的形成和分布,异常高压裂缝的形成与有机质含量有关,受有机质热演化程度的控制。The papersummarized characteristics and main controlling factors for distributionof fractures inshale ofLower CambrianNiutitang Formation,throughobservation and description offractures inshale outcrops,cores andslices,discussedthe genetic types,distribution characteristics of fractures,content of brittle minerals,shale thickness,mechanical properties of rock,structure,lamellation development,relationship betweenthe content of organic matter and the thermal evolution degree. The results show thatthe nearly E-W direction fractures,the NE direction fractures and the nearly S-N direction fractures are the three main groupsoftectonic fractures. The nearly E-W direction fractures are mostly developed. Shale fracturesare mostly high-angle shear fractures. They have small scale and common reservoir capability,but they play a main role in percolation process. Brittle minerals content is the key internal factor that controls the formation and distribution of shale fractures. Stratum thickness, rock mechanical property,tectonic stress andstructure position are the key external factors. The development of lamellation influences the formation and distribution of bedding fractures and low angle decollement fractures. The formation of abnormal high-pressure fractures are related to organic matter content and controlled by thermal evo-lution of organic matter.

关 键 词：渝东南 牛蹄塘组 页岩 裂缝 成因类型 控制因素 

分 类 号：P618.12[天文地球—矿床学] TE132.2[天文地球—地质学]