塔里木盆地中下寒武统白云岩储集层特征、成因及分布  

Characteristics, origin and distribution of dolomite reservoirs in Lower-Middle Cambrian, Tarim Basin, NW China

作　　者：沈安江 郑剑锋 陈永权[3] 倪新锋 黄理力 

机构地区：[1]中国石油杭州地质研究院 [2]中国石油集团碳酸盐岩储层重点实验室 [3]中国石油塔里木油田公司

出　　处：《石油勘探与开发》2016年第3期340-349,共10页Petroleum Exploration and Development

基　　金：国家重大科技专项"大型油气田及煤层气开发"(2011ZX05004-002);中国石油天然气股份有限公司重大科技专项"深层油气勘探开发关键技术研究"(2014E-32-02)

摘　　要：基于盆地钻遇中下寒武统18口井的岩心、薄片和单井资料及两条露头剖面,开展微区(指在不同成岩作用事件中形成的同类成岩矿物)地球化学分析和储集层溶蚀模拟实验,研究塔里木盆地中下寒武统白云岩储集层类型、成因和分布。塔里木盆地中下寒武统发育台缘礁滩、台内丘滩和台内膏云岩3类白云岩储集层,其中,台内膏云岩储集层又可分为潜山型和内幕型两个亚类;储集层岩石类型有藻礁(丘)白云岩、砂屑白云岩和膏云岩,藻礁(丘)白云岩储集层以藻格架(溶)孔为主,砂屑白云岩储集层以粒间、粒内(溶)孔及晶间(溶)孔为主,膏云岩储集层以石膏铸模孔及微孔隙为主。礁滩相和膏云坪沉积中的沉积原生孔是储集层发育的关键,准同生期未白云石化的灰质、膏质为早表生溶蚀孔洞的发育奠定了物质基础,准同生白云石化作用形成的白云岩构成坚固的岩石格架对孔隙起到保护作用。中下寒武统台缘礁滩储集层既有规模,储集层物性又好,是非常现实的勘探对象,而下寒武统肖尔布拉克组台内礁滩储集层和中下寒武统内幕型膏云岩储集层的潜力较好。Based on cores, thin sections and drilling data of 18 wells and two outcrop profiles of the Lower-Middle Cambrian in the Tarim Basin, geochemical analysis of multi-parameters in micro-area（the same type of diagenetic minerals formed in different diagenetic events） and reservoir dissolution modeling were carried out to find out the types, origin and distribution of Lower-Middle Cambrian dolomite reservoirs. There develop three types of dolomite reservoirs, margin reef-shoal reservoir, platform interior mound-shoal reservoir and platform interior gypsodolomite reservoir. The rock types include algae dolomite, grain dolomite, and gypsodolomite; the pore types in them include algae framework pores in algae dolomite; intergranular pores, intra-granular dissolved pores, inter-crystalline dissolved pores in grain dolomite and gypsum-dissolved pore gypsodolomite. The primary pores in sediments of reef-shoal facies and gypsodolomite flat are the key to the development of the dolomite reservoirs, some aragonite and calcite are the material basis of dissolution in early supergene stage, and the dolomite formed in penecontemporaneous dolomitization acts as strong rock skeleton to protect the primary pores from destructive effect in burial stage. The margin reef-shoal reservoirs, large in scale and good in physical properties, are the most practical exploration targets; furthermore, the platform interior reef-shoal reservoirs in Lower Cambrian Xiaoerbulake Formation and platform interior gypsodolomite reservoir in the Middle-Lower Cambrian have higher oil and gas potential.

关 键 词：塔里木盆地 中下寒武统 白云岩 储集层 台缘礁滩 台内丘滩 膏云岩 

分 类 号：TE122.2[石油与天然气工程—油气勘探]