中国南方海相与陆相页岩裂缝发育特征及主控因素对比——以黔北岑巩地区下寒武统为例  

Comparative analysis of characteristics and controlling factors of fractures in marine and continental shales: A case study of the Lower Cambrian in Cengong area,northern Guizhou Province

作　　者：王濡岳 胡宗全[1,2] 刘敬寿 王兴华[3] 龚大建[4] 杨滔 Wang Ruyue;Hu Zongquan;Liu Jingsliou;Wang Xinghua;Gong Dajian;Yang Tao(Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China;State Key Laboratory of Shale Oil andGas Enrichment Mechanisms and Effective Development,Beijing 100083,China;School of Energy Resources,China University ofGeosciences(Beijing),Beijing 100083,China;China Energy Reserve Corporation,Beijing 100107,China;College of Geosciences, China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]页岩油气富集机理与有效开发国家重点实验室,北京100083 [3]中国地质大学(北京)能源学院,北京100083 [4]中国国储能源化工集团股份公司,北京100107 [5]中国石油大学(北京)地球科学学院,北京102249

出　　处：《石油与天然气地质》2018年第4期631-640,共10页Oil & Gas Geology

基　　金：国家科技重大专项(2017ZX05036002-001;2017ZX05036004-001;2017ZX05036004-007)

摘　　要：依据裂缝发育特征与对应分析测试资料,分析了下寒武统变马冲组二段(变二段)页岩裂缝发育特征、主控因素及海相与陆相页岩裂缝发育的差异性。结果表明,变二段兼具海相与陆相页岩部分特征,页岩段裂缝以低角度层理、层间和滑脱缝为主,与陆相页岩相似;砂泥互层与砂岩段裂缝发育程度高,以高角度构造缝为主。裂缝发育受构造应力、岩性与矿物组分、地层厚度、TOC和储层非均质性影响,主要表现为:岩性与岩石力学性质控制构造缝的发育,地层厚度控制裂缝的密度与尺度,TOC控制层间超压裂缝发育,储层非均质性控制层理缝的发育。海相与陆相页岩TOC、石英、脆性和裂缝具有不同耦合特征,海相页岩较大的脆性与单层厚度利于储层改造,但在强改造下易发育穿层裂缝,不利于保存。陆相页岩较低的单层厚度、较强的塑性与非均质性能有效避免穿层裂缝的发育,利于页岩气保存。变二段不同岩性组合及其裂缝发育特征与主控因素对海相与陆相页岩气保存、富集与储层改造等方面具有一定参考价值。The study analyzed the shale fracture characteristics,controlling factors and differences of fractures developed in marine and continental shales in the second Member of the Lower Cambrian Bianmachong Formation(1 b 2)based on fracture observation and experimental data.The results show that the 1 b 2 shales show certain features of both marine and continental shales.Its fractures are dominated by fractures at low angle with bedding,interlayer and slip fractures,which are similar to those in continental shales.The fractures in sandstone-shale alternating intervals and sandstone intervals are highly developed,with the high dip-angle structural fractures being dominant.The controlling factors of fracture development are mainly represented as follows:lithology and rock mechanical property control structural fracture development;stratum thickness controls the density and scale of fractures;TOC influences the development of interlayer overpressure fractures;and reservoir heterogeneity controls the development of bedding-parallel fractures.In addition,the TOC,quartz content,brittleness and fracture have different coupling relationships in marine and continental shales.Although the greater brittleness and single layer thickness of marine shale are favorable for reservoir stimulation,cross-layer fractures may form easily under strong deformation,thus are unfavorable for hydrocarbon preservation.However,continental shales have lower single layer thickness,stronger ductility and heterogeneity.They can effectively prevent the development of cross-layer fractures,thus can facilitate the preservation of shale gas.In general,the different lithologic combinations and their corresponding characteristics and controlling factors of fracture development in the 1 b 2 are of referential value in the aspects of gas preservation,enrichment and reservoir stimulation in marine and continental shale gas.

关 键 词：非均质性 海相页岩 陆相页岩 裂缝 页岩 上扬子地区 

分 类 号：TE121.1[石油与天然气工程—油气勘探]