三水盆地布心组湖相碳酸盐岩沉积特征及相模式  

Sedimentary characteristics and facies model of lacustrine carbonate rocks of Buxin Formation,Sanshui Basin

作　　者：唐鑫萍[1,2] 雷栋 宋效文 TANG Xin-ping;LEI Dong;SONG Xiao-wen(Research Institute of Exploration and Development,Dagang Oilfield Company,CNPC,Tianjin 300280,China;PetroChina(Tianjin)International Petroleum Exploration&Development Technology Co.Ltd.,Tianjin 300280,China;PetroChina South Petroleum Exploration and Development Co.Ltd.,Haikou 570216,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 [2]中油(天津)国际石油勘探开发技术有限公司,天津300280 [3]中国石油南方石油勘探开发有限责任公司,海南海口570216

出　　处：《天然气地球科学》2021年第5期675-684,共10页Natural Gas Geoscience

基　　金：国家科技重大专项子课题(编号:2016ZX05026003);中国石油科技项目(编号:2019D-0707)联合资助.

摘　　要：运用岩心、岩石薄片、扫描电镜、X-射线衍射和微量元素等资料,分析三水盆地布心组湖相碳酸盐岩沉积特征及相模式。结果表明:①三水盆地布心组碳酸盐岩主要有泥灰岩、生物灰岩、泥晶灰岩3类,岩性总体较细,基质含量高、颗粒含量较低,胶结物主要为泥晶,单层厚度较薄。②布心组碳酸盐岩形成于贫外物源的湖盆缓坡背景,总体水动力较弱;形成于贫氧—缺氧条件下的半咸水—咸水沉积环境;表现为总体较弱水动力条件下的咸水化学沉积和局部生物沉积。③建立了受控于古地形与湖浪的缓坡碳酸盐岩沉积模式,碳酸盐岩主要发育于滨湖—浅湖区域,滨湖可分为砂泥坪、灰泥坪2个微相,浅湖可分为生物浅滩、灰泥浅湖、泥质浅湖3个微相,不同微相的碳酸盐岩发育情况具有较明显的分异性,灰泥坪优势岩性为泥灰岩、生物浅滩优势岩性为生物灰岩、灰泥浅湖优势岩性为泥晶灰岩。研究成果可为该区碳酸盐岩沉积相工业化制图和储层分布预测提供依据。This paper aims at the sedimentary characteristics and sedimentary facies model of lacustrine carbonate rocks of Buxin Formation in Sanshui Basin. Petrological characteristics were analyzed by using core,thin section,scanning electron microscope and X-ray diffraction data. Combined with trace element data,sedimentary environment analysis was carried out. The carbonate sedimentary facies model is established based on the analysis of continuous well profile. The results are as follows:①The carbonate rocks of Buxin Formation in Sanshui Basin are mainly composed of muddy limestone,biological limestone and micrite limestone. The overall lithology of carbonate rocks is fine,with high matrix content and low particle content. The cement is mainly mud crystal. The thickness of single layer is thin.②The carbonate rocks of Buxin Formation were formed in the gentle slope environment of lake basin with poor provenance. The overall hydrodynamic force is weak. It is formed in the oxygen-poor and anoxic environment. It is characterized by saline water chemical deposition and local biological deposition under relatively weak hydrodynamic conditions.③The sedimentary model of gentle slope carbonate rock controlled by paleotopography and lake wave is established. Carbonate rocks are mainly developed in the lakeside shallow lake area. The lakeside can be divided into two microfacies:sand mud flat and muddy lime flat. The shallow lake can be divided into three microfacies:biological shoal,muddy lime shallow lake and muddy shallow lake. The development of carbonate rocks with different microfacies has obvious differentiation. The dominant lithology of muddy lime flat is muddy limestone. The dominant lithology of biological shoal is biolimestone. The dominant lithology of muddy lime shallow lake is micritic limestone. The research results can provide basis for industrial mapping of carbonate sedimentary facies and prediction of reservoir distribution.

关 键 词：湖相碳酸盐岩 岩石学特征 沉积环境 沉积微相 沉积模式 古近系 三水盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]