塔里木盆地北部震旦系齐格布拉克组白云岩储层特征及成因  

Dolostone reservoir characteristic and its formation mechanism in Qigebulake Formtion,Sinian,north Tarim Basin

作　　者：石书缘[1] 刘伟[1] 黄擎宇[1] 王铜山[1] 周慧[1] 王坤[1] 马奎[1] Shi Shu-yuan Liu Wei Huang Qing-yu Wang Tong-shan Zhou Hui Wang Kun Ma Kui(Research Institution of Petroleum Exploration ＆ Development, PetroChina ,Beijing 100083, China)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《天然气地球科学》2017年第8期1226-1234,共9页Natural Gas Geoscience

基　　金：国家科技重大专项(编号:2016ZX05004);中国石油股份公司科技重大专项(编号:2014E-32-01)联合资助

摘　　要：塔里木盆地震旦系齐格布拉克组发育一套以碳酸盐岩为主的古老地层,它的形成时代老,埋藏深度大,后期改造强烈,储层成因控制因素复杂。露头剖面、岩心观察和150个薄片分析表明,齐格布拉克组发育微生物白云岩、颗粒白云岩、晶粒白云岩和混积岩4种类型,比例分别占30%、25%、30%和15%。齐格布拉克组储集空间包括孔隙(原生孔、次生孔和微生物岩相关孔)、溶洞和裂缝(构造溶蚀缝和缝合线)3种类型。68个露头和岩心样品测试揭示,微生物白云岩孔隙度集中分布在2.5%~3.5%之间;晶粒白云岩中晶间孔隙和溶蚀孔洞发育,孔隙度分布在2%~4%之间,最大的可达9%,且晶体越粗,孔隙度和渗透率越好;颗粒白云岩中溶蚀孔洞发育,孔隙度分布在2%~3.5%之间,部分可达7%。在此基础上,综合碳氧同位素和包裹体数据,认为大气淡水溶蚀作用是储层的主要贡献者,埋藏阶段构造—热液溶蚀作用对储层保存和再改造起重要作用。Carbonate stratigraphy developed in the Sinian, Qigebulake Formation, Tarim Basin, which is mainly composed of carbonate ancient stratum,formed the old geological times.Core observation,thin section analysis and outcrop measurement showed that the petrological type of Qigebulake Formation contains microbial dolomite,grain dolostone,crystalline grain dolostone and hybrid sedimentary rock. The statistics data of 150 thin sections show that microbial dolomite accounted for about 30%,grain dolostone for 25%, crystalline dolostone for 30% ,and peperite accounted for 15%.The reservoir space type of Qigebulake Formation contains inter-crystalline pore, inter-granular pore, microbial lattice, solution cavity, and fracture. By collecting and testing porosity and permeability data, it is proposed that microbial dolomite porosity distrib- uted between 2.5 % and 3.5 ~/00.The grain crystalline dolostone porosity value distributed between 2Y00-4~, and the biggest can be close to 9%.The bigger the grain size, the greater the permeability and porosity. Tgrain dolostone porosity ranges from 2% to 3.5% ,partly up to 7% which is related to inter-granular cor- rosion cavity reservoir space.On this basis of carbon and oxygen isotope and inclusion data analysis, com- bined with the sedimentary microfacies, atmospheric fresh water dissolution is the main contributor of reservoir.Burial dissolution and tectonic hydrothermal process for reservoir preservation and transformation also play an important role in reservoir formation.

关 键 词：塔里木盆地 震旦系 微生物白云岩 白云岩储层 大气淡水溶蚀 构造热液作用 

分 类 号：TE122.2[石油与天然气工程—油气勘探]