四川盆地须家河组致密砂岩物源体系的控储作用

Reservoir control of tight sandstone provenance system in Xujiahe Formation,Sichuan Basin

为明确四川盆地须家河组致密砂岩物源特征及控储作用,运用储层岩石学测试和镜下分析,研究了物源与储层发育的关系及分布,探讨了物源体系的控制因素。研究结果表明,四川盆地须家河组储层具有成分成熟度较低、物性差异性强、以中-细粒为主、主要为溶蚀孔隙和成岩效应存在两面性5个基本特征;物源控制了储层岩石类型的发育范围,平面展布存在差异性,其可溶矿物组分及含量亦有所不同,导致各地区孔隙发育及规模有所不同;西部龙门山和东北部大巴山是须家河组的主要供源区,前者表现为碳酸盐岩岩屑含量相对较高,后者表现为火山岩岩屑含量相对较高。不同时期造山活动强度的阶段性变化使得物源供应强度及类型也随之变化,储层岩石组分差异分化,进而控制储层垂向非均质性。研究成果可以为该区下一步的油气精细勘探提供借鉴。

In order to clarify the provenance characteristics and reservoir control of tight sandstone in Xujiahe Formation of Sichuan Basin,by means of reservoir petrology test and microscopic analysis,the relationship and distribution between provenance and reservoir development are studied,and the controlling factors of provenance system are discussed.The results show that the Xujiahe Formation reservoir in Sichuan Basin has five basic characteristics:low composition maturity,strong physical property difference,mainly medium fine grain,mainly dissolution pores and two sides of diagenetic effect;the provenance controls the development range of reservoir rock types,the plane distribution is different,and the composition and content of soluble minerals are also different,which leads to different porosity Longmenshan in the West and Dabashan in the Northeast are the main source areas of Xujiahe Formation.The former shows relatively high content of carbonate cuttings,while the latter shows relatively high content of volcanic cuttings.The stage change of orogenic activity intensity in different periods leads to the change of provenance supply intensity and types,the differentiation of reservoir rock components,and then controls the vertical heterogeneity of reservoir.The research results can provide reference for the next fine oil and gas exploration in this area.