白云岩与砂岩致密储集体质量的差异性  

Quality differences between dolomite and tight sandstone reservoirs

作　　者：魏新善[1,2] 陈娟萍[1,2] 吕奇奇[3] 赵小会[1,2] 贾亚妮[1,2] Wei Xinshan;Chen Juanping;Lyu Qiqi;Zhao Xiaohui;Jia Ya’ni(Exploration and Development Institute of Changqing Oilfield Branch Company,PetroChina,Xi’an,Shaanxi 710018,China;National Engineering Laboratory of Exploration and Development of Low Permeability Oil/Gas Fields,Xi’an,Shaanxi 710018,China;Hubei Cooperative Innovation Center of Unconventional Oil and Gas,Yangtze University,Wuhan,Hubei 430100,China)

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [3]长江大学非常规油气湖北省协同创新中心,湖北武汉430100

出　　处：《石油与天然气地质》2019年第2期294-301,共8页Oil & Gas Geology

基　　金：国家科技重大专项(2016ZX05050;2016ZX05046)

摘　　要：白云岩与砂岩致密储集体质量参数为随机分布的连续谱系,孔隙结构、物理参数复杂多变,表征难度较大。基于铸体薄片、压汞、核磁共振、孔隙度和渗透率等测试技术,结合大量天然气勘探开发实际资料,采用统计分析对比方法,重点讨论了储层质量宏观与微观参数特征。结果表明,白云岩与砂岩致密储集体质量参数具有正态分布特征,是一种金字塔数据结构,常规储层比例一般为15%～20%,是砂岩或白云岩致密储层的"甜点";致密砂岩储层微观孔隙发育,孔、喉连通性较好,分布比较均匀,储层孔、渗关系较好,表现为相对高孔和低渗;白云岩致密储层质量尽管具有孔、喉连通性差和孔、渗关系较差的不利因素,但也具有相对高渗、低束缚水饱和度、低排驱压力及裂缝网络发育等有利因素,天然气渗流能力较好,勘探开发潜力较大。我国发育碳酸盐岩沉积,应加强致密白云岩气藏成藏条件研究与勘探。The quality parameters of dolomite and tight sandstone reservoirs are a randomly distributed continuum.Their pore structures and physical parameters are complex and changeable,and are thus hard to be characterized.With the help of techniques such as thin section casting,mercury injection,nuclear magnetic resonance(NMR),and measurements of porosity and permeability,and a large number of data for natural gas exploration and development,we focused the study on analyzing and comparing the macroscopic and microscopic characteristics of the parameters of the reservoir quality.Results show that the quality parameters of dolomite and tight sandstone reservoirs are normally distributed in a pyramidal data structure.The proportion of conventional reservoirs is generally ranging from 15 % to 20 %,which are the “sweet spots” of the sandstone or tight dolomite reservoirs.The microscopic pores are well developed with good pore-throat connectivity and uniform distribution in the tight sandstone reservoirs.The reservoir porosity and permeability are of good relationship,showing relatively high porosity and low permeability.The tight dolomite reservoirs,however,are characterized by unfavorable factors including poor pore-throat connectivity and poor relationship of porosity and permeability,while having certain favorable factors of its kind including relatively high permeability,low irreducible water saturation,low displacement pressure,and better development of fracture networks.These favorable factors keep the natural gases flow well in tight dolomite reservoirs,indicating great potentials for the exploration and development of hydrocarbons.Carbonate deposits are well developed in China,so the exploration of tight dolomite gas reservoirs and study on their accumulation conditions should be strengthened.

关 键 词：砂岩 白云岩 储层质量 致密储层 天然气 靖边气田 苏里格气田 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]