川中南部地区下二叠统栖霞组白云岩储层成因研究  

THE GENESIS OF THE DOLOMITIC RESERVOIRS OF THE LOWER PERMIAN QIXIA FORMATION IN THE SOUTH CENTRAL SICHUAN BASIN

作　　者：赵娟 曾德铭[1] 梁锋[2] 范玲[2] 侯甫[2] 宋林珂 王家树[2] 滕怡葳[3] ZHAO Juan;ZENG Deming;LIANG Feng;FAN Ling;HOU Fu;SONG Linke;WANG Jiashu;TENG Yiwei(School of Geosciences,Southwest Petroleum University,Chengdu 610500,Sichuan,China;Chuanzhong Petroleum Resource Plant,Southwest Oil and Gas Company,CNPC,Suining 629000,Sichuan,China;Institute of geological exploration and development,Chuanqing drilling company,CNPC,Chengdu 610051,Sichuan,China)

机构地区：[1]西南石油大学地球科学与技术学院,四川成都610500 [2]中国石油西南油气田公司川中油气矿,四川遂宁629000 [3]中国石油川庆钻探公司地质勘探开发研究院,四川成都610051

出　　处：《地质力学学报》2018年第2期212-219,共8页Journal of Geomechanics

基　　金：中国石油西南油气田分公司川中油气矿项目(20150302-02-04)

摘　　要：川中南部地区下二叠统栖霞组在钻探中发现栖二段细—中晶白云岩是良好的储层,并且多口井获得工业气流,展示出一定勘探潜力。为进一步预测川中南部地区白云岩的储层分布特征,加快研究区下一步勘探开发,应用储层岩性特征识别、碳氧同位素、包裹体测温、阴极发光以及稀土元素分析研究白云岩储层成因,结果表明栖霞组白云岩无石膏或其他蒸发盐岩伴生,储集岩以细—中晶白云岩和灰质白云岩为主,主要分布于栖二段;栖霞组白云岩C、O同位素测试δ^(13)C为4.03‰~4.77‰、古盐度为131.74~133.39,包裹体均一温度为110~180℃,阴极发光较弱,基质白云岩发紫红色光,溶洞充填马鞍状白云岩不发光;稀土元素的轻稀土和重稀土分布趋势一致,保持了原岩的稀土配分趋势;综合分析认为栖二段白云岩为埋藏成因,其中裂缝和溶洞充填的马鞍状白云岩为热液成因。During the exploration of the south central Sichuan Basin,the fine-medium grained dolostones of Lower Permian Qixia Formation was found as good reservoir rocks.Industrial gas flows were obtained in numbers of development wells,which reveals great potentiality of the gas exploration.For the further prediction of dolomite reservoir distribution characteristics in central and southern regions,speeding up the next exploration and development of the study area,the genesis of dolomite reservoir is studied through the application of reservoir lithology recognition,carbon and oxygen isotope,fluid inclusion,cathodoluminescence and rare earth elements analysis in this study.The results show that,in the Qixia Formation,the dolostones formed without associated gypsum or other evaporites;the reservoir rocks are mainly gray fine-medium grained dolostones,which spread mainly in the Qier Group.According to a series of reservoir rock analysis,theδ13 C content is 4.03~4.77‰;the paleosalinity varies among 131.74~133.39;the homogenization temperatures of fluid inclusions are among 110~180℃;the cathodeluminescence is fairly weak,and the dolomitic matrix reflects purple red light,while the saddle dolomite filled in the vugs absorbs all the light;the distribution tend of light rare earth elements and heavy ones are consistent with the protolith.Overall,in this study it is believed that the Qier Group dolomites were formed during the burial stage,while saddle dolomites filled in the vugs and fractures were formed due to a hydrothermal cause.

关 键 词：栖霞组 白云岩 阴极发光 包裹体 埋藏成因 热液成因 

分 类 号：P618.13[天文地球—矿床学]