粤中地区三水盆地布心组湖相碳酸盐岩致密油储层特征  

Characteristics of Tight Oil Reservoir of Lacustrine Carbonate Rocks of Buxin Formation in Sanshui Basin of Central Guangdong Area, China

作　　者：唐鑫萍[1] TANG Xin-ping(Research Institute of Exploration and Development,Dagang Oilfield Company,CNPC,Tianjin 300280,China)

机构地区：[1]中国石油大港油田公司勘探开发研究院,天津300280

出　　处：《地球科学与环境学报》2021年第4期724-734,共11页Journal of Earth Sciences and Environment

基　　金：国家科技重大专项项目(2016ZX05026003);中国石油科技项目(2019D-0707)。

摘　　要：为研究粤中地区三水盆地古近系布心组湖相碳酸盐岩的岩性、物性、源储配置关系等储层要素,综合运用测录井资料、岩芯描述、薄片鉴定、X射线衍射及扫描电镜等资料开展岩性及含油气性分析;结合孔渗分析、微米CT扫描等资料,开展物性分析;再结合布心组烃源岩资料,开展源储配置关系分析。结果表明:三水盆地布心组碳酸盐岩主要有泥灰岩、云质泥灰岩、泥晶灰岩、泥晶砂屑灰岩、生物灰岩等岩石类型,岩性总体较细;碳酸盐岩分布于湖盆两侧斜坡的滨、浅湖区域,总体表现为以湖盆缓坡为基底的泥岩与碳酸盐岩间互沉积;碳酸盐岩孔隙度为2.8%~9.6%,渗透率一般小于1 mD;较致密储层内发育有由裂缝、微米级基质孔隙、少数溶蚀孔组成的储集空间,组成基质孔-裂缝型、溶蚀孔-裂缝型两种孔隙结构;孔隙、裂缝中普遍含油,油气显示活跃,一般具有油迹—油斑显示级别;浅湖—半深湖形成的暗色泥岩总有机碳为1%~2%,高丰度的暗色泥岩与碳酸盐岩相互叠置,形成良好的互层型源储配置关系;储层初步评价表明,分布于浅湖的泥晶灰岩、泥晶砂屑灰岩、生物灰岩的方解石矿物含量高,分布较连续,储层物性相对较好,源储配置关系好,为潜在有利储层。In order to study lithology, physical property and source-reservoir allocation relation of lacustrine carbonate rocks of Paleogene Buxin Formation in Sanshui Basin of central Guangdong area, the logging, core description, thin section identification, X-ray diffraction(XRD) and scanning electron microscope data were comprehensive used to analyze the lithology and oil-gas potential;combined with the porosity and permeability analysis, and micro CT scan test, the physical properties were analyzed;combined with the source rock data of Buxin Formation, the source-reservoir allocation relation was analyzed. The results show that carbonate rocks mainly include muddy limestone, dolomitic muddy limestone, micrite limestone, micritic arenaceous limestone and biological limestone, the lithology is fine in general;carbonate rocks are distributed in the lakeside and shallow lake on the both sides of lake basin, the lake basin gentle slope is generally taken as the basement, and the mudstone and carbonate rock are intercalated;the porosity of carbonate rock is 2.8%-9.6%, and the permeability is generally less than 1 mD;in the tight reservoir, the reservoir spaces are composed of fractures, micron matrix pores and a few dissolution pores, which form two pore structures, including matrix pore-fracture type and dissolution pore-fracture type;oil is commonly found in pores and fractures, and oil-gas display is generally active with the oil stain-oil spot display level;the total organic carbon(TOC) of dark mudstone formed in shallow-semi deep lakes is 1%-2%;dark mudstone and carbonate rock with high abundance overlap each other, forming a good source-reservoir allocation relation. The preliminary evaluation of reservoir shows that the micritic limestone, micritic arenaceous limestone and biological limestone distributed in the shallow lake have high mineral content, continuous distribution, relatively good reservoir physical properties and good source-reservoir allocation relation, and are potential favorable reservoirs.

关 键 词：致密油 湖相碳酸盐岩 布心组 储层 岩性 源储配置关系 三水盆地 广东 

分 类 号：P618.13[天文地球—矿床学]