北部湾盆地涠西南凹陷灰岩潜山储层岩溶识别及发育模式  

Karst Identification and Development Model of Buried Hill Limestone Reservoir in Weixinan Depression, Beibuwan Basin

作　　者：谢兵[1] 徐昉昊[1] 范彩伟 满勇 江凡 徐国盛[1] 张喜淳 李安然 Xie Bing;Xu Fanghao;Fan Caiwei;Man Yong;Jiang Fan;Xu Guosheng;Zhang Xichun;Li Anran(National Key Laboratory of Reservoir Geology and Development Engineering(Chengdu University of Technology),Chengdu 610059,China;CNOOC China Limited,Zhanjiang Branch,Zhanjiang 524057,Guangdong,China)

机构地区：[1]油气藏地质及开发工程全国重点实验室(成都理工大学),成都610059 [2]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《吉林大学学报（地球科学版）》2024年第6期2029-2046,共18页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学青年基金项目(42302186);中海石油(中国)有限公司湛江分公司项目(CCL2023ZJFN0540)。

摘　　要：涠西南凹陷灰岩潜山勘探程度低,剩余资源勘探潜力大,二号断裂带周缘已发现多个潜山油田或含油构造,显示良好的勘探前景。本文综合运用钻井、录井、岩心、薄片、成像测井等资料,对二号断裂带碳酸盐岩储层发育特征、岩溶结构进行了系统研究,并根据构造演化与沉积背景综合分析了X构造岩溶储层的演化发育模式。研究结果表明:二号断裂带X构造古潜山岩性主要为灰岩类、灰质白云岩类,储集空间以溶蚀孔、洞、缝为主,孔隙度在0.01%~35.88%之间变化,但平均值偏低,仅为4.30%;以X-1井为例,X构造表生岩溶储层自上而下划分为表层风化带、垂直渗流带、水平潜流带和深部缓流带,水平潜流带岩溶缝/洞发育最优,为优质储层发育带;X构造裂缝-溶洞型灰岩潜山储层发育程度主要受岩相、古地貌及后期构造运动三者控制。岩相决定了溶蚀作用的发育程度,构造运动使地层抬升产生差异化剥蚀以及形成大量的裂缝,为后期岩溶作用提供了有利的渗流空间。古地貌控制了潜水面的相对位置从而控制岩溶的发育位置,岩溶斜坡高部位受到的岩溶作用最强。综合3个控制因素建立了“岩性筑基-裂缝拓容-岩溶改造”的三元耦合碳酸盐岩缝-洞型储层发育模式。The exploration degree of buried hill limestone in Weixinan sag is low,and the exploration potential of remaining resources is large.Several buried hill oil fields or oil-bearing structures have been discovered around the No.2 fault zone,which shows a good exploration prospect.In this paper,the development characteristics and karst structure identification of carbonate reservoir in No.2 fault zone are systematically studied by using the data of drilling,logging,core,thin section and image logging,and the evolution and development model of karst reservoir in X structure is comprehensively analyzed according to the tectonic evolution and sedimentary background.The results show that the lithology of the buried hill of the X structure in the No.2 fault zone is mainly limestone and lime dolomite,and the reservoir space is dominated by solution pores,caverns and fractures.The porosity varies from 0.01%to 35.88%,but the average value is only 4.30%.Taking well X 1 as an example,the supergene karst reservoir of X structure is divided into surface weathering zone,vertical seepage zone,horizontal subsurface flow zone and deep slow flow zone from top to bottom.The horizontal subsurface flow zone has the best karst fractures/caverns and is a high-quality reservoir development zone.The development degree of X tectonic fracture-cavern type limestone buried hill reservoir is mainly controlled by lithofacies,paleogeomorphology and late tectonic movement.The lithofacies determined the development degree of dissolution,and the tectonic movement caused differentiated denudation and formed a large number of fractures,which provided favorable percolation space for the later karst process.The paleogeomorphology controlled the relative position of the diving surface and thus controlled the development position of karst,and the high part of the karst slope was subjected to the strongest karst process.Based on three controlling factors,the three-element coupling reservoir development model of“lithology foundation building,fracture capac

关 键 词：北部湾盆地 涠西南凹陷 碳酸盐岩潜山 储层特征 岩溶作用 储层发育模式 

分 类 号：P618.13[天文地球—矿床学] TE12[天文地球—地质学]