珠江口盆地惠州26-6潜山中生代中基性火山岩储层成因  

Genesis of Mesozoic intermediate-basic volcanic reservoirs in Huizhou 26-6 buried hill,Pearl River Mouth Basin,China

作　　者：冷杰 刘杰 陈安清[1] 蔡俊杰 何陵沅 侯明才[1] 曹海洋 黄志发 钟灵 LENG Jie;LIU Jie;CHEN Anqing;CAI Junjie;HE Lingyuan;HOU Mingcai;CAO Haiyang;HUANG Zhifa;ZHONG Ling(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China;CNOOC (China) Limited Shenzhen Branch, Shenzhen 518054, 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]中海石油(中国)有限公司深圳分公司,广东深圳518054

出　　处：《成都理工大学学报（自然科学版）》2021年第6期661-674,共14页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中海石油(中国)有限公司深圳分公司科技项目(CCL2020SZPS0304)。

摘　　要：探讨珠江口盆地惠州凹陷西南惠州26-6潜山中基性火山岩储层成因及控制因素。通过岩心观察、薄片鉴定、成像测井、储层物性测试及扫描电镜等资料,研究其岩石学特征、储集空间类型、储层物性特征,以及裂缝、流体性质对储层的控制作用。结果表明:储层储集空间类型主要为晶间孔、晶间溶孔、晶内溶孔、溶蚀孔洞及裂缝;储层物性测试显示微观孔隙极低,孔隙度平均为1.2%,渗透率平均为0.012×10^(-3)μm^(2),岩心视面孔率统计揭示宏观缝洞是主要储集空间,平均值约4.7%;裂缝是储层发育的主导因素,以多期次形成的30°~70°斜交缝为主,包括NW、NE及近EW向3个方向;流体溶蚀作用是储层缝-洞系统形成的关键,燕山末期的大气淡水溶蚀长石等不稳定矿物形成了大量与裂缝沟通的孔洞,深部热液流体及有机酸溶蚀作用进一步提升了储集性能。惠州26-6潜山中基性火山岩储层为裂缝主导的叠加大气淡水和酸性流体溶蚀形成的缝-洞体系,证实了中基性火山岩潜山具备良好的成储能力。The reservoir petrological characteristics,reservoir space types,reservoir physical characteristics,and the effect of crack and fluid properties on the control of reservoir in Huizhou 26-6 buried hill basic volcanic rock are studied by using core observation,thin section identification,imaging logging and reservoir physical property test and scanning electron microscopy(SEM)and other information so as to investigate the causes and the control factors of reservoir.The results show that the main types of reservoir space are intergranular pore,intergranular solution pore,intragranular solution pore,dissolution pore and fracture.The test of reservoir physical properties shows that the microscopic pores in the rocks are very low,with an average porosity of 1.2%and permeability of 0.012×10^(-3)μm^(2).Statistics of apparent face ratio of cores reveal that the macroscopic fractures and caverns developed in the rocks are the main reservoir spaces,with an average of 4.7%.Fractures are the dominant factor of reservoir development,and they are mainly 30°~70°oblique fractures formed in multiple periods,including NW,NE and nearly EW direction.Fluid dissolution is the key to the formation of fracture-cavity system.Atmospheric freshwater dissolution of feldspar and other unstable minerals in the late Yanshanian period formed a large number of pores connecting with fractures,and deep hydrothermal fluid and organic acid dissolution further improved the reservoir performance.It is considered that the intermediate-basic volcanic rock reservoir in Huizhou 26-6 buried hill is a fracture-cave system dominated by superimposed atmospheric fresh water and acid fluid dissolution,which confirms that the intermediate-basic volcanic rock buried hill has good reservoir forming ability.

关 键 词：中基性火山岩 储层 惠州26-6构造带 裂缝作用 珠江口盆地 

分 类 号：TE122.222[石油与天然气工程—油气勘探]