深层灰岩孔隙发育与保持机理--以四川盆地中部上二叠统长兴组为例  

Formation and preservation of pores in deep limestone reservoirs:A case study of Upper Permian Changxing Formation,central Sichuan Basin,SW China

作　　者：文龙[1] 罗冰[1] 张本健[1] 陈骁[1] 李文正 刘一锋 胡安平 张玺华[1] 沈安江 WEN Long;LUO Bing;ZHANG Benjian;CHEN Xiao;LI Wenzheng;LIU Yifeng;HU Anping;ZHANG Xihua;SHEN Anjiang(PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China;State Energy Key Laboratory of Oil and Gas in Carbonate Strata,Hangzhou 310023,China;Key Laboratory of Carbonate Reservoirs,CNPC,Hangzhou 310023,China;PetroChina Hangzhou Institute of Petroleum Geology,Hangzhou 310023,China;Zhejiang University,Hangzhou 310058,China)

机构地区：[1]中国石油西南油气田公司,成都610051 [2]国家能源碳酸盐岩油气重点实验室,杭州310023 [3]中国石油集团碳酸盐岩储层重点实验室,杭州310023 [4]中国石油杭州地质研究院,杭州310023 [5]浙江大学,杭州310058

出　　处：《石油勘探与开发》2025年第2期292-305,共14页Petroleum Exploration and Development

基　　金：国家自然科学基金企业创新发展联合基金项目(U23B20154);国家自然科学基金面上项目(42372169)。

摘　　要：近年来四川盆地蓬深10、合深9、潼深17和正阳1等井钻探证实深层上二叠统长兴组发育一套孔隙型礁滩复合体灰岩储层,突破了深层碳酸盐岩大油气田主要分布于孔隙型白云岩储层和岩溶缝洞型灰岩储层的传统认识。基于岩心和薄片观察、储层地球化学特征分析、井震联合的储层识别和追踪,开展深层礁滩灰岩孔隙形成机理研究,取得4个方面认识:①深层长兴组孔隙型礁滩复合体灰岩储集空间以粒间孔、格架孔、生物体腔孔、铸模孔和溶孔为主,形成于沉积和早表生环境;②断续分布的多孔礁滩复合体被相对致密的泥晶灰岩包裹,在复合体持续增温条件下导致局部异常高压的形成;③长兴组储层的底板为上二叠统吴家坪组互层的致密泥岩和灰岩,顶板为下三叠统飞仙关组一段致密泥晶灰岩夹泥岩,在致密顶底板的夹持下,导致长兴组区域异常高压的形成;异常高压(超压封存箱)是沉积和早表生环境形成的孔隙在深层得以保持的关键;④在顶底板和礁滩复合体识别基础上,通过井震联合预测有利礁滩灰岩储层分布面积达10.3×10^(4) km^(2)。上述认识奠定了深层孔隙型灰岩储层发育的理论基础,拓展了四川盆地深层灰岩储层勘探新领域。In recent years,drilling data from wells Pengshen 10,Heshen 9,Tongshen 17 and Zhengyang 1 in the Sichuan Basin have confirmed the presence of a set of porous reef-beach limestone reservoirs in the Upper Permian Changxing Formation,which breaks the traditional view that deep carbonate oil and gas are distributed in porous dolomite reservoirs and karst fracture-cavity limestone reservoirs.Through core and thin section observations,reservoir geochemical analysis,and well-seismic based reservoir identification and tracking,the study on formation mechanism of pores in deep reef-beach limestone reservoirs is carried out,this study provides insights in four aspects.(1)Porous reef-beach limestone reservoirs are developed in the Changxing Formation in deep-buried layers.The reservoir space is composed of intergranular pores,framework pores,biological cavity pores,mold pores and dissolution pores,which are formed in sedimentary and early surface environments.(2)The intermittently distributed porous reef-beach complexes are surrounded by relatively dense micrite limestone,which leads to the formation of local abnormal high-pressure inside the reef-beach complexes under the continuously increasing temperature.(3)The floor of the Changxing Formation reservoir is composed with interbedded tight mudstone and limestone of the Upper Permian Wujiaping Formation,and the roof is the tight micrite limestone interbedded with mudstone of the first member of Lower Triassic Feixianguan Formation.Under the clamping of dense roof and floor,the abnormal high-pressure in the Changxing Formation is formed.Abnormal high-pressure(overpressured compartment)is the key to maintain the pores formed in the sedimentary and surface environments in deep-buried layers.(4)Based on the identification of roof,floor and reef-beach complexes,the favorable reef-beach limestone reservoir distribution area of 10.3×10^(4) km^(2) is predicted by well-seismic combination.These insights lay the theoretical foundation for the development of deep porous limestone re

关 键 词：深层 灰岩 孔隙型礁滩灰岩储层 孔隙形成与保持 异常高压 长兴组 四川盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]