川中北部地区寒武系第二统沧浪铺组一段孔隙特征、成因及演化模式  

Pore Characteristics,Genesis,and Evolution Model of the First Member of the Canglangpu Formation from the Cambrian Series 2 in the Central and Northern Sichuan Basin

作　　者：屈海洲[1,2] 邹兵 张连进[3] 赵容容 张宇 唐松[3] 张兴宇 李文皓 马梓柯 雷银 QU HaiZhou;ZOU Bing;ZHANG LianJin;ZHAO RongRong;ZHANG Yu;TANG Song;ZHANG XingYu;LI WenHao;MA ZiKe;LEI Yin(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;School of Geosciences and Technology,Southwest Petroleum University,Chengdu 610500,China;Central Sichuan Oil and Gas Mine,PetroChina Southwest Oil and Gas Field Company,Suining,Sichuan 629000,China;Exploration Department,PetroChina Southwest Oil&Gas Field Company,Chengdu 610000,China;Engineering Technology Research Institute,PetroChina Southwest Oil and Gas Field Company,Chengdu 610017,China)

机构地区：[1]西南石油大学油气藏地质及开发工程全国重点实验室,成都610500 [2]西南石油大学地球科学与技术学院,成都610500 [3]中国石油西南油气田分公司川中油气矿,四川遂宁629000 [4]中国石油西南油气田分公司勘探事业部,成都610000 [5]中国石油西南油气田分公司工程技术研究院,成都610017

出　　处：《沉积学报》2024年第5期1723-1737,共15页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41702163,42272181);中国石油—西南石油大学创新联合体科技合作项目(2020CX010301)。

摘　　要：【目的】近年来,随着川中北部地区寒武系第二统沧浪铺组的不断勘探突破,沧浪铺组呈现出巨大的勘探潜力,而目前孔隙研究的薄弱制约了对储层发育特征的深入认识。【方法】基于岩心、铸体薄片和阴极发光等的观察与鉴定,运用图像识别软件获取岩石组分含量、孔隙参数等定量数据,对川中北部地区寒武系第二统沧浪铺组一段的孔隙特征、成因、不同岩性的孔隙演化模式开展研究。【结果】沧浪铺组一段的孔隙类型主要为粒内溶孔,与总面孔率的正相关性最好,其次是粒间溶孔。较高的鲕粒/陆源砂的含量比例是孔隙发育的重要物质基础,溶解作用是孔隙发育的最有利因素,而高能的陆棚鲕粒滩沉积是原生孔隙发育的关键。因为准同生期大气水的选择性溶解作用是形成沧一段主要鲕粒粒内溶孔的最有利的成岩作用,而准同生期—埋藏期的白云石化作用则增强岩石的抗压性、使固相体积缩小而增加岩石的面孔率,埋藏期的溶解作用则沿着构造破裂形成的裂缝和早期孔隙进行溶解扩大。陆源砂、胶结作用、压实作用和压溶作用等则不利于沧一段孔隙的发育。【结论】因此,有利的碳酸盐组分及后续的成岩—构造作用影响了孔隙的发育和演化,并形成了孔隙面孔率依次降低的岩性排序特征:亮晶鲕粒云岩、含砂鲕粒云岩、砂质鲕粒云岩、细粒岩屑砂岩、石灰岩类。[Objective]In recent years,there has been a continuous exploration of the Canglangpu Formation from the Cambrian Series 2 in the central and northern Sichuan Basin,which exhibits substantial exploration potential.At present,the study of pores is relatively weak,restricting the in-depth understanding of reservoir development characteristics.[Methods]Based on the observation and identification of cores,cast thin sections,and cathode luminescence,image recognition software was used to obtain quantitative data of rock components and pore parameters.The pore characteristics,genesis,and evolution models of different lithological pores in the First member of the Canglangpu Formation were studied.[Results]The results show that:the pore type of the First member of Canglangpu Formation was mainly intragranular dissolved pores,which have the best positive correlation with the total face rate,followed by intergranular dissolved pores.The higher oolite/terrigenous sand content ratio is an important material basis for pore development,dissolution is the most favorable factor for pore development,and high energy shelf oolitic beach sedimentation is the key to the development of primary pores.The selective dissolution of atmospheric water in the syngenetic period is the key to the formation of the most important dissolution pores in oolitic sands in the First member of Canglangpu Formation,while the dolomitization in the quasi syngenetic and burial period enhances the compression resistance of rocks,reduces the solid volume,and increases the pores.The dissolution in the burial period is located along the fractures by tectonic disruption and early pores expansion.Terrigenous sand,cementation,compaction,and pressure dissolution are not conducive to the development of pores in the First member of the Canglangpu Formation.[Conclusions]Therefore,favorable carbonate components and subsequent diagenesis and tectonism have affected the development and evolution of pores and formed the lithologic sequence characteristics of the decreasin

关 键 词：孔隙特征 孔隙演化 沧浪铺组 第二统 寒武系 川中北部地区 

分 类 号：P618.13[天文地球—矿床学]