低渗透致密气藏微观孔隙结构及渗流特征研究:以苏里格气田苏48和苏120区块储层为例  

Microscopic Pore Structure and Seepage Characteristics of Low-Permeability and Tight Sandstone Gas Reservoir: Taking Blocks Su 48 and Su 120 in Sulige Gas Field as An Example

作　　者：庞振宇[1,2] 孙卫[1,2] 李进步[3] 马二平[1,2] 高航[1,2] 

机构地区：[1]西北大学大陆动力学国家重点实验室,西安710069 [2]西北大学地质学系,西安710069 [3]中国石油长庆油田公司苏里格气田研究中心,西安710018

出　　处：《地质科技情报》2013年第4期133-138,共6页Geological Science and Technology Information

基　　金：国家科技支撑计划项目(2007BAB17B02);国家科技重大专项(2011ZX05044)

摘　　要：利用常规与恒速压汞、核磁共振等实验资料,对苏里格气田苏48和苏120区块低渗透储层的储集空间、孔隙结构类型及渗流特征的研究结果表明,溶蚀型次生孔隙为该区的主要储集空间,晶间孔相对发育、残余粒间孔分布较少,伴有微裂缝发育时,晶间孔转化为有利储集空间;该区储层的孔隙结构类型可分为粗态型、偏粗态型、偏细态型及细态型,4种孔隙结构类型的储集空间组合类型依次变差;低渗透储层的品质主要受喉道控制,喉道是决定其开发效果的关键因素;与常规气藏相比,苏里格气田低渗透储层相对渗透率曲线参数特征为:储层的束缚水饱和度较高,等渗点较低,共渗区较窄。其中Ⅰ类、Ⅱ类储层的储集空间类型较好,喉道发育程度较好,可动流体饱和度较高,稳产时间相对较长;Ⅲ类储层的储集空间类型较差,喉道发育程度较差,可动流体饱和度较低,稳产时间相对较短。The reservoir space,pore structure type and seepage characteristics of blocks Su 48 and Su 120 in Sulige gas field are analyzed by using conventional mercury injection technology,constant-rate mercury injection technology,nuclear magnetic resonance and so on.It is showed that the reservoir space of studied area is dominated by solution-type secondary porosity.Intercrystalline pore is relatively more and residual intergranular pore is relatively small.Intercrystalline pore may be good reservoir sites owing to the fracture connecting the pores.Pore structure can be classified as wide form,less wide form,rather narrow form and narrow form,and their reservoir space become worse sequentially.The quality of low-permeability reservoir is mainly controlled by throat,and it is the key factor affecting the development.Compared with conventional gas reservoirs,parameters characteristics of relative permeability curves in the study area are as follows： irreducible water saturation becomes high.The isotonic point becomes low and the two-phase region becomes narrow under the condition of two-phase seepage.Reservoir space types,throat development and movable fluid saturation of different-type reservoirs are different,which results in the difference of stable production period.

关 键 词：苏里格 储集空间 孔隙结构 喉道 孔喉特征 渗流特征 

分 类 号：TE122.23[石油与天然气工程—油气勘探]