石油勘探与开发2025，Vol.52Issue(2)：292-305,14.DOI:10.11698/PED.20240411
深层灰岩孔隙发育与保持机理
Formation and preservation of pores in deep limestone reservoirs:A case study of Upper Permian Changxing Formation,central Sichuan Basin,SW China
摘要
Abstract
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 10.3×104km2 is predicted by well-seismic combination.These insights lay the theoretical foundation for the development of deep porous limestone reservoirs,expand the new field of exploration of deep-buried limestone reservoirs in the Sichuan Basin.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Key words
deep layer/porous reef-beach limestone reservoir/formation and preservation of pores/abnormal high-pressure/Changxing Formation/Sichuan Basin分类
石油、天然气工程引用本文复制引用
文龙,罗冰,张本健,陈骁,李文正,刘一锋,胡安平,张玺华,沈安江..深层灰岩孔隙发育与保持机理[J].石油勘探与开发,2025,52(2):292-305,14.基金项目
国家自然科学基金企业创新发展联合基金项目(U23B20154) （U23B20154）
国家自然科学基金面上项目(42372169) （42372169）
