天然气工业2026，Vol.46Issue(8)：46-59,14.DOI:10.3787/j.issn.1000-0976.2026.08.004
四川盆地中部地区侏罗系沙溪庙组二段储层特征差异及其形成机理
Differences in reservoir characteristics of the second member of the Jurassic Shaximiao Formation in the central Sichuan Basin and their formation mechanisms
摘要
Abstract
The Jinqiu Block,as one of the core productivity construction areas for the Middle Jurassic Shaximiao Formation gas reservoir in the Sichuan Basin,is currently in the development stage.However,the differences in reservoir characteristics among the sand groups—which serve as fundamental development units—and their underlying formation mechanisms remain poorly understood,which restricts the sweet spot evaluation and well placement.Based on experiments such as casting thin sections,scanning electron microscopy(SEM),X-ray diffraction,physical property testing,and constant-rate mercury injection,this paper characterizes the macroscopic and microscopic reservoir differences among No.6 to 9 sand groups in the 2nd member of Shaximiao Formation(Sha 2 Member)in the central Sichuan Basin,and analyzes the mechanisms driving these reservoir differences.The following results are obtained.First,among these sand groups,No.7 exhibits the best physical properties and the largest average throat radius,followed by No.6,whereas No.8 and No.9 display the poorest physical properties and the smallest average throat radii.Second,these sand groups differ significantly in cement contents,which can be divided into chlorite-zeolite cement facies,chlorite cement facies,and I/S mixed layer-illite cement facies.Third,no significant differences are observed in average pore radius among these sand groups,whereas the throat-radius distribution shifts leftward and becomes narrower as reservoir quality deteriorates.Fourth,the continuous uplift of the Dabashan tectonic belt during the Middle Jurassic is the fundamental reason for the differences in reservoir characteristics among No.6 to 9 sand groups.In conclusion,the macroscopic physical properties of No.6 to No.9 sand groups are directly controlled by the throat size,and the differences in microscopic characteristics are under the control of the chain differentiation among magma material content,diagenetic fluid environment,water-rock reaction types,and comprehensive reservoir-forming effects induced by the provenance migration.关键词
四川盆地川中地区/中侏罗统沙溪庙组二段/致密砂岩气藏/储层特征差异/形成机理/喉道尺寸/物源迁移Key words
Central Sichuan Basin/Second member of the Jurassic Shaximiao Formation/Tight sandstone/Differences in reservoir characteristics/Formation mechanisms/Throut size/Provenance migration分类
能源科技引用本文复制引用
蒋裕强,朱讯,蒋婵,邓海波,殷修宇,李杪,王占磊,冯林杰..四川盆地中部地区侏罗系沙溪庙组二段储层特征差异及其形成机理[J].天然气工业,2026,46(8):46-59,14.基金项目
重庆市自然科学基金面上项目"基于成岩系统剖析的致密砂岩储层差异致密化机理及渗流差异响应研究"(编号:CSTC2021JCYJ-MSXMX0897)、中国石油西南油气田公司重大专项"四川盆地中西部地区致密气勘探开发理论及关键技术研究"(编号:2022ZD01). （编号:CSTC2021JCYJ-MSXMX0897）
