江陵凹陷深层储层次生孔隙非均质性成因  

Genesis of heterogeneity of secondary pores in deep reservoir of Jiangling Depression

作　　者：陈波[1] 韩定坤 赵海涛[1] 赖志云[1] 

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北荆州434023 [2]中国石油化工股份公司中南分公司,湖南长沙410117

出　　处：《石油学报》2006年第5期66-70,共5页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.40173023)资助

摘　　要：在江陵凹埋深超过3000m的晚白垩纪地层发现了次生孔隙发育的砂岩储层油气藏，次生孔隙以粒间填隙物溶孔为主，但次生孔隙的发育程度存在严重的非均质性，控制了有效油气藏的形成。储层在成岩过程中受到层水pH值变化的影响，经历1-3个世界的胶结成溶蚀作用，其中在晚成岩期油气生成和运移过程中形成的酸性成岩环境对早成岩期生成的碳酸盐岩胶结物和储层中的长石矿物溶蚀，因而产生了大量的次生溶孔，但随后溶孔中沉淀了不等量的硬石膏，导致了次生孔隙的非均质性。硬石膏胶结物的含 量与储层岩石中长石矿物成分的含量密切相关，石英砂岩内硬石膏胶结物含量低，长石砂岩的硬石膏胶结物含量高。造成这种现象的主要原因是储层中长石矿物的溶解为硬石膏在乳隙中的沉淀促进了物质来源。The reserveirs developing secondary pores over 3000 meters in depth of Jiangling Depression during the late Gretaceous period were found in recent years.The secondary pores mainly resulted from cement dissolution have serious heterogeneity and control the formation of effective oil reservdirs.As pH value varied in the coures of diagenesis,reservoirs experiexced one to three cementations or dissolution generations,Lots of secondary dissolution pores developed in the late diagenctic stage,because of the acidic mediums in the process of generation and migration of oil and gas.The anhydrites deposited in the dissolved pores resulted in the heterogeneity of secondary pores.The contents of anhydrites cements closely conneeted with that of the feldspar in reservoir rock,The content of anhydrites cements in qunrtzose sandstone is low,and the content of that in felspathic sandstone is high.The main cause of such phenomena is that feldspar solution provided sourees for the deposition of anhydrites in dissolved pores.

关 键 词：江陵凹陷 深储层 次生孔隙 储层非均质性 硬石膏胶结构 长石溶解 

分 类 号：TE112.23[石油与天然气工程—油气勘探]