摘要
致密气储层气水关系复杂,气井产能会随着气井见水而迅速降低。为明确致密气储层流体赋存与气水共渗规律,以定北区块和大牛地区块致密气储层为研究对象,采用渗吸、离心、核磁共振和气水驱替等实验方法,研究压裂过程中流体含量变化、动态分布以及生产过程中气水两相共渗规律。结果表明:在压裂过程中,致密气储层岩心对压裂液的自发渗吸先快后慢,流体先进入较小孔隙中,流体分布随渗吸时间增大而更加集中。在返排过程中,较大孔隙中的流体在返排时优先排出,存在可动流体向束缚流体的转变。同时还分析了储层物性参数与流体赋存的关系,渗吸量、返排率与岩石物性存在正相关关系。定北区块气水相渗曲线束缚水饱和度大,共渗区小,在生产过程中储层内气水两相干扰严重,见水后气相相对渗透率迅速降低。
In order to clarify the law of fluid occurrence and gas water co-permeability in tight gas reservoirs,tight gas reservoirs in Dingbei block and Daniudi block were taken as the research objects,and the experimental methods of imbibition,centrifugation,NMR and gas water displacement were used to study the change and dynamic distribution of fluid content during fracturing and flowback,as well as the law of gas water two-phase flow during production.The results show that:In the process of fracturing,the spontaneous imbibition of tight gas reservoir cores to fracturing fluid is first fast and then slow.The fluid first enters smaller pores,then the fluid distribution becomes more concentrated.In the process of flowback,the fluid in larger pores is preferentially discharged,and some movable fluid becomes bound fluid.At the same time,there is a positive correlation between imbibition capacity,flowback rate and rock physical properties.The gas-water relative permeability curves of the Dingbei block have large irreducible water saturation and small co-permeability area.During the production process,the gas-water two-phase interference in the reservoir is serious,and the gas relative permeability decreases rapidly after water breakthrough.
作者
李彬册
赖枫鹏
赵立斌
许东东
逯广腾
LI Bince;LAI Fengpeng;ZHAO Libin;XU Dongdong;LU Guangteng(School of Energy Resources,China University of Geosciences,Beijing,Beijing 100083,China;Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering,Beijing 100083,China;Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2021年第9期1410-1419,共10页
Natural Gas Geoscience
基金
国家自然科学基金面上项目“致密气储层渗透率瓶颈区表征及气相相对渗透率改善方法研究”(编号:51774255)
国家科技重大专项“十三五”课题“致密油气藏数值模拟新方法与开发设计”(编号:2017ZX05009-005)联合资助。
关键词
致密气储层
流体赋存
动态分布
模拟返排
气水相渗
Tight gas reservoir
Fluid occurrence
Dynamic distribution
Simulated backflow
Gas-water relative permeability
