摘要
天然裂缝的发育不但改善了页岩储层的储集品质,也为开发阶段水力压裂形成大规模的缝网提供了有利条件。以黔北地区凤冈区块下志留统龙马溪组页岩为例,通过野外露头观测、岩心裂缝统计、含气性分析等方法,深入分析了研究区宏观裂缝发育特征和页岩气保存条件。结果表明:龙马溪组页岩裂缝类型以构造裂缝为主;根据构造应力强弱、构造变形样式及裂缝发育类型等特征,将研究区构造保存有利区进一步划分为稳定区和弱变形区,稳定区地层变形较弱,构造主体为宽缓背斜和紧闭向斜,断裂不发育,裂缝多以非构造裂缝为主,致使页岩气自封闭性良好,有利气体富集,是页岩气保存的有利区。分析裂缝与含气量关系发现,龙马溪组页岩储层中裂缝发育程度和含气量有着良好的对应关系。
The development of natural fractures not only improves the reservoir quality of shale reservoir,but also provides favorable conditions for the formation of large-scale fracture network in the development stage of hydraulic fracturing.Taking Longmaxi shale of Lower Silurian in Fenggang Block of northern Guizhou as an example,through the methods of outcrop observation,core fracture statistics and gas bearing analysis,the macro fracture development characteristics and shale gas preservation conditions in the study area are analyzed in depth.The results show that the fracture types of Longmaxi shale are mainly structural fractures.According to the characteristics of structural stress,structural deformation pattern and fracture development type,the study area is further divided into stable area and weak deformation area.In the stable area,the formation deformation is relatively weak,the main structure is wide and gentle anticline and tight syncline,the fault is not developed,and the fracture is mainly non structural fracture,resulting in good self sealing of shale gas and favorable gas enrichment,which is a favorable area for shale gas preservation.By analyzing the relationship between fracture and gas bearing property,it is found that there is a good corresponding relationship between fracture development degree and gas bearing property in Longmaxi Formation shale.
作者
谷阳
徐晟
张炜
徐佳佳
翟中杨
GU Yang;XU Sheng;ZHANG Wei;XU Jiajia;ZHAI Zhongyang(Geoscience Documentation Center,CGS,Beijing 100083,China;National Geological Library of China,Beijing 100083,China;No.4 Oil Production Plant,Huabei Oilfield Company,PetroChina,Langfang 062550,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2021年第6期733-738,共6页
Fault-Block Oil & Gas Field
基金
中国地质调查局战略性矿产资源勘查开发科技跟踪项目(DD20211407)。
关键词
龙马溪组页岩
裂缝发育特征
页岩气保存条件
复杂构造区
黔北地区
Longmaxi Formation shale
fracture development characteristics
shale gas preservation conditions
complex structural area
northern Guizhou
