川东北黄龙场地区长兴组白云岩成因  

Genesis of Changxing Formation dolomite in Huanglongchang area,northeast Sichuan Basin,China

作　　者：李怡 文华国[1] 徐文礼[1] 赵松[2] 曾汇川[2] 曹刚[2] 胡雯雯[2] 李丹[2] 肖俊[2] LI Yi;WEN Huaguo;XU Wenli;ZHAO Song;ZENG Huichuan;CAO Gang;HU Wenwen;LI Dan;XIAO Jun(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;Northeast Sichuan Gas Field,PetroChina Southwest Oil & Gas Field Company,Dazhou 635000,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]中国石油西南油气田分公司川东北气矿,四川达州635000

出　　处：《成都理工大学学报（自然科学版）》2019年第1期41-52,63,共13页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家科技重大专项(2017ZX05032-001-003)

摘　　要：研究川东北黄龙场地区二叠系长兴组优质白云岩储层的成因,指导天然气勘探。以岩心描述、薄片和古生物鉴定为依据,结合长兴组白云岩X射线衍射、阴极发光、扫描电镜等岩石组构分析,以及痕量元素、碳氧锶同位素地球化学分析,认为长兴组白云岩主要有准同生白云岩和埋藏白云岩2种成因类型。推测长兴期同生卤水通过近地表环境蒸发泵作用形成准同生期白云岩,来源于早-中三叠世蒸发岩溶解产生的高盐度埋藏循环海源孔隙水,沿着先期存在的断裂或裂缝和T-P不整合面,对长兴组台缘礁坪或礁盖滩微相及部分毗邻发育的骨架礁微相灰岩进行白云石化等叠加改造作用,形成不同类型埋藏白云岩。The genesis of Permian Changxing Formation dolomite reservoir in the northeastern Sichuan Basin is studied on the basis of ore description, thin section and fossil identification, combined with the analyses of X-ray diffraction, cathodoluminescence, scanning electron microscopy, rock formation analysis, trace element, carbon and oxygen isotope geochemical analysis, so as to provide theoretical and practical help for the exploration of natural gas. The Permian biological reef beach gas reservoir in the northeastern Sichuan Basin is one of the main reservoirs of natural gas production in the Sichuan Basin. It is considered that the Changxing Formation dolomite is mainly classified into penecontemporary dolomite and buried dolomite. Contemporaneous brine in the Changxing period formed pseudo-contemporaneous dolomite through the near-surface evaporating pump. The high salinity porous water resulted from the dissolution of early to middle Triassic evaporite migrates through early formed faults and T-P unconformity surface and dolomitization occurs in the Changxing Formation platform marginal reef flat and reef cover beach microfacies, eventually, forms different types of buried dolomite.

关 键 词：白云岩 成岩流体 白云石化 成因 长兴组 四川盆地 

分 类 号：P588.245[天文地球—岩石学]