川东北元坝地区须三段储集层形成机制

Formation mechanism of 3rd Member of Xujiahe Formation reservoir in Yuanba Area of northeast Sichuan Basin

何曼如¹ 孙廷彬 3 王玲 3 刘鹏⁴

成都理工大学“油气藏地质及开发工程”国家重点实验室，四川 成都 610059 中国石化中原油田博士后工作站，河南 郑州 457000 中国石化中原油田分公司勘探开发研究院，河南 郑州 457000 中国石化胜利油田分公司勘探开发研究院，山东 东营 257015

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China Postdoctoral Research Workstation, Zhongyuan Oilfield Company, SINOPEC, Zhengzhou 450000, China Research Institute of Exploration and Development, Zhongyuan Oilfield Company, SINOPEC, Puyang 457000, China Research Institute of Exploration and Development, Shengli Oilfield Company, SINOPEC, Dongying 257015, China

为解决元坝地区须三段储集层形成机制不清等问题，指导油气勘探实践，应用铸体薄片、扫描电镜、黏土矿物X衍射等资料对其开展了研究。结果表明：元坝地区须三段碎屑岩储集层具有富岩屑、贫长石、少石英的低成分成熟度特征；储集层总体上属于特低孔特低渗的致密砂岩储集层；物源供应稳定、水动力条件中等沉积环境下形成的厚层河道钙屑砂体是形成有效储集层的基础；生排烃过程中产生的有机酸溶蚀可溶矿物是形成次生孔隙的关键；构造作用形成的裂缝是增大储集层储集空间和提高渗滤能力的保障。研究结果对于元坝地区须三段寻找有利储集体具有重要意义。

In order to solve the problem of unclear mechanism about the reservoir of the 3rd Member of Xujiahe Formation and guide oil gas exploration, research has been carried out based on casting, scan electron microscope and X-ray diffraction. The results show that: the reservoir has the characteristics of abundant lithoclast, few feldspar, lack of quarta and low composition maturation; the reservoir belongs to tight sandstone reservoir with super-low porosity and super-low permeability; the steady provided provenance and moderate hydrodynamic condition are the basis of developing thickness calcarenaceous sandstone, and the calcarenaceous sandstone is the favorable reservoir; the process of hydrocarbon generation-expulsion can generate organic acid, and the organic acid is the key to secondary pore developed; tectonic process can generate fracture, and fracture can increase reservoir space and enhance permeable ability. These research results are significant to seek favorable reservoirs in the 3rd Member of Xujiahe Formation in Yuanba Area.

10.6056/dkyqt201601002