塔里木盆地奥陶系缝洞型碳酸盐岩岩溶储层成因及勘探启示  

Genesis and exploration enlightenment of Ordovician fracture-vuggy carbonate karst reservoirs in Tarim Basin

作　　者：倪新锋 沈安江 乔占峰 郑剑锋 郑兴平 杨钊 NI Xinfeng;SHEN Anjiang;QIAO Zhanfeng;ZHENG Jianfeng;ZHENG Xingping;YANG Zhao(Hangzhou Institute of Geology,PetroChina,Hangzhou 310023,China;Key Laboratory of Carbonate Reservoir,PetroChina,Hangzhou 310023,China)

机构地区：[1]中国石油杭州地质研究院,杭州310023 [2]中国石油碳酸盐岩储层重点实验室,杭州310023

出　　处：《岩性油气藏》2023年第2期144-158,共15页Lithologic Reservoirs

基　　金：国家科技重大专项“大型油气田及煤层气开发”(编号:2016ZX05004-002);中国石油科技重大专项“深层—超深层油气成藏规律与先进探测技术”03课题(编号:2018A-0103)联合资助。

摘　　要：以岩心薄片、实验分析数据、钻录井、测井、地震等资料为基础,按照储层成因机理对塔里木盆地奥陶系碳酸盐岩岩溶储层进行了分类,并对各类储层的分布、储集空间类型及主控因素进行了系统分析。研究结果表明:(1)塔里木盆地奥陶系缝洞型岩溶储层按成因可划分为5类,分别为(准)同生岩溶储层、层间岩溶储层、顺层岩溶储层、潜山(风化壳)岩溶储层和受断裂控制岩溶储层。(2)(准)同生岩溶储层分布于台缘或台内礁滩相,有效储层在台缘连片发育,在台内零星分布,由颗粒灰岩因海平面下降而短期暴露淋溶形成,基质孔和溶缝、溶洞均发育,通常叠加后期层间岩溶作用或潜山岩溶作用,从而形成复合型岩溶储层。(3)层间岩溶储层发育于内幕区,与碳酸盐岩层系内部中短期的平行或微角度不整合面相关,呈准层状分布,储集空间以洞穴型为主,裂缝-孔洞型和孔洞型次之。(4)顺层岩溶储层与潜山周缘的斜坡背景、先存孔隙和裂缝有关,环潜山周缘呈环带状分布,以洞穴型和裂缝-孔洞型为主,90%以上的溶蚀孔洞及洞穴通过断裂及裂缝相连通。(5)潜山(风化壳)岩溶储层发育于潜山区,与中长期的角度不整合面相关,受断裂和裂缝影响大,准层状分布,峰丘地貌特征明显,根据围岩岩性分为灰岩潜山岩溶储层和白云岩风化壳岩溶储层,灰岩缝洞系统发育、基质孔不发育,白云岩缝洞欠发育,以白云岩晶间溶孔、裂缝为主。(6)受断裂控制岩溶储层主要发育于内幕断裂发育区,缝洞发育埋深大、规模大、跨度长,沿断裂呈栅状分布,以裂缝-孔洞型为主,断裂-洞穴型次之,断裂和裂缝越发育,溶蚀孔洞和洞穴也越发育,单井试油产能更高更稳定。(7)研究区岩溶储层在内幕区大量发育,主要为顺层岩溶储层和受断裂控制岩溶储层,勘探潜力大。Based on core thin section,experimental analysis,drilling,logging and seismic data,the Ordovician carbonate karst reservoirs in Tarim Basin were classified according to the reservoir genetic mechanism,and the distribution,space types and main control factors of various reservoirs were analyzed.The results show that:(1)The Ordovician fracture-vuggy karst reservoirs in Tarim Basin can be divided into five types according to their genesis:(quasi-)syngenetic karst reservoirs,interlayer karst reservoirs,bedding karst reservoirs,buried hill(weathering crust)karst reservoirs and fault-controlled karst reservoirs.(2)(Quasi-)syngenetic karst reservoirs,also known as reef-shoal karst reservoirs,are the reservoir formed by short-term(transient)exposure and leaching of reefshoal facies granular limestone at the platform edge or within the platform due to sea level drop,with matrix pores,dissolved fractures and dissolved caves being developed.They are usually superimposed with later interlayer karst or buried hill karst to form complex karst reservoirs.(3)The interlayer karst reservoirs are developed in the inner zone,and they are related to the parallel(micro-angle)unconformity surface in the carbonate strata and distributed quasi-stratified.The reservoir space is mainly cave type,followed by fracture-vuggy type and vuggy type.(4)The bedding karst reservoirs are related to the slope background,pre-existing pores and fractures around the buried hill,and the surrounding of the buried hill is distributed in a ring band,dominated by vuggy type and fracture-vuggy type,and more than 90%of the dissolved pores and caves are connected through faults and fractures.(5)The buried hill(weathering crust)karst reservoirs are developed in buried hill area.They are related to medium to long-term angle unconformity and greatly affected by faults and fractures.They are quasi-stratified and have obvious characteristics of peak and hill geomorphology.According to the lithology of the surrounding rocks,they can be divided into limestone buried hi

关 键 词：缝洞型碳酸盐岩储层 岩溶作用 潜山区 内幕区 断裂控储 鹰山组 一间房组 奥陶系 塔里木盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]