鄂尔多斯盆地WPS地区长9储层成岩作用特征  

Diagenetic characteristics of Chang 9 reservoir in WPS area,Ordos Basin

作　　者：霍建伟 侯煜菲 康昱 陈刚[1] 夏晓雨 李晓珂 张法乾 党子豪 王冰雪 刘奥杰 Huo Jianwei;Hou Yufei;Kang Yu;Chen Gang;Xia Xiaoyu;Li Xiaoke;Zhang Faqian;Dang Zihao;Wang Bingxue;Liu Aojie(Department of Geology,Northwestern University,Xi'an,Shaanxi,710069,China;Research Institute Yanchang Petroleum Group,Xi'an,Shannxi,710061,China;The eighth geological brigade of Hubei Geological Bureau,Xiangyang,Hubei,441000,China;Gansu provincial Seismological Bureau,Lanzhoun,Gansu,730030,China;Petrochina Changqing Oilfield company exploration and development Research Institute,Xi'an,Shaanxi,710003,China)

机构地区：[1]西北大学地质学系,陕西西安710069 [2]陕西延长石油(集团)有限责任公司研究院,陕西西安710061 [3]湖北省地质局第八地质大队,湖北襄阳441000 [4]甘肃省地震局,甘肃兰州730030 [5]中国石油长庆油田分公司勘探开发研究院,陕西西安710003

出　　处：《新疆地质》2024年第4期578-586,共9页Xinjiang Geology

摘　　要：鉴于WPS地区长9储层成岩序列及孔隙演化不明确,开展薄片鉴定、铸体薄片、粒度分析、岩心物性分析、扫描电镜、全岩X衍射分析和高压压汞等方法,分析研究区长9储层特征、成岩作用特征及孔隙度演化过程,揭示了成岩作用对储层孔隙度演化的影响及控制作用。结果表明:①研究区长9储层主要发育中-细粒长石砂岩,储集空间以粒间孔-次生溶孔为主,孔隙度平均12.3%,渗透率平均4.57 mD,为低孔、低渗-超低渗储层;②研究区主要包括压实、胶结、溶蚀和交代4种成岩作用,溶蚀作用为建设性成岩作用,是形成优质储层的重要成因;压实和胶结作用为破坏性成岩作用,极大地降低了储层物性;③基于成岩作用定量恢复各阶段孔隙度及成岩演化参数,统计原始孔隙度平均值为39.97%,压实减孔率平均值为56.025%,胶结减孔率平均值为24.82%,溶蚀增孔率平均值为10.96%;④基于成岩序列及埋藏史等研究,划分储层孔隙度演化过程为早成岩阶段(压实+早期胶结作用)-减孔、中成岩阶段A1期(溶蚀作用)-增孔和中成岩阶段A2期(晚期胶结+油气充注)-减孔3个阶段,孔隙度在趋近停止之前下降至12.03%,较为合理地恢复了孔隙演化过程。通过定性+定量分析储层成岩及孔隙演化过程的方法对于同类型砂岩储层的成储机理、有利“甜点区”综合评价与预测及后续高效勘探开发的推进具有实际意义。Due to diagenetic sequence and pore evolution of Chang 9 reservoir in WPS block is not yet clear,this study characterizes the reservoir,diagenesis and porosity evolution process of Chang 9 through experimental data from thin section analysis,casting sheets,scanning electron microscopy,whole rock X-ray diffraction analysis and high-pressure mercury intrusion,revealing the influence and control of diagenesis on the evolution of reservoir porosity.The results shows,(1)The Chang 9 reservoir in the study area is mainly developed with medium-fine grained arspathic sandstone,which predominantly features intergranular and secondary dissolution pores,with an average porosity of 12.3%and an average permeability of 4.57 mD.It exhibits low-porosity and low to ultra-low permeability characteristics.(2)The member mainly experienced 4 types of diagenesis including compaction,cementation,corrosion and metasomatism,Corrosion is a constructive diagenetic process,which plays an important part in forming high-quality reservoirs.Compaction and cementation are destructive diagenetic processes,which greatly reduce the reservoir physical properties.(3)Based on the porosity and diagenetic evolution parameters at each stage of diagenetic quantitative restoration,the average value of original porosity is 39.97%,the average value of compaction porosity reduction is 56.025%,the average value of cementation porosity reduction is 24.82%,and the average value of solution porosity increase is 10.96%.(4)According to studies on diagenetic sequence and burial history,the porosity evolution experienced three stages including early diagenetic stage(compaction+early cementation)-porosity reduction,middle diagenetic stage A1(dissolution)-porosity increase,and middle diagenetic stage A2(late cementation+oil and gas charging)-porosity reduction.The porosity drops to 12.03%before halting.The pore evolution process is reasonably restored by methods in study.In this paper,with qualitative and quantitative analysis to study diagenesis and pore evolution is p

关 键 词：储层特征 成岩作用特征 孔隙度演化 长9储层 鄂尔多斯盆地 

分 类 号：P618.130.21[天文地球—矿床学] P612[天文地球—地质学]