摘要
准确评价致密气藏裂缝和基质系统渗透率对评价其可采储量和产能等方面具有重要意义.基于致密气藏裂缝岩心非稳态测试流动特征和物理模型,建立了裂缝岩心非稳态测试流动数学模型,采用Laplace变换和Stehfest数值反演,得到了上游和下游腔室的无因次拟压力解和特征曲线,分析了不同参数对无因次拟压力特征曲线的影响.结果表明,裂缝岩心的非稳态渗流可划分为3个阶段:裂缝渗流阶段、基质渗流阶段和系统平衡阶段.在裂缝渗流阶段,裂缝渗透率越大,持续时间越短;裂缝孔隙度对该渗流阶段基本没有影响.在基质渗流阶段,基质渗透率越小,达到平衡所需时间越长;基质孔隙度越小,平衡系统压力越大.本文研究为评价致密气藏裂缝岩心属性提供一种评价方法.
It is significant to accurately evaluate the fracture and matrix permeability of tight sandstone reservoirs. Based on the unsteady state test flow characteristics and physical model of tight sandstone reservoirs, unsteady flow mathematical model in fractured core has been proposed and solved by the Laplace transformation method and Stehfest numerical inversion method, which acquired pressure response mathematical model of upstream and downstream. The fluid cross flow characteristic curve for the fractured core in tight sandstone gas reservoirs has been obtained and studied in this paper. Base on the unsteady state test flow theoretical, the unsteady state test experimental of fractured core in tight sandstone gas reservoirs has been studied, which is used to analyses on property of fractured core. The results show that the process of the flow for fractured core in tight sandstone gas reservoirs can be divided into three sections, including the fracture seepage period for gas flowing crossed in fractured from upstream to downstream; the matrix seepage period for gas flowing crossed in matrix from upstream, downstream and fractured to matrix; and the system equilibrium period. During fracture seepage period, the higher fracture permeability is, the shorter duration of fracture seepage period is; however fracture porosity does not have influence on the fracture seepage period. In addition, the matrix seepage periods greatly affected by matrix permeability and matrix porosity. The lower matrix permeability is, the longer the time required to reach the equilibrium. The smaller the matrix porosity is, the greater the equilibrium system pressure is. The methods and results of this research contribute to reasonable analyses on property of fractured core in tight sandstone gas reservoirs.
作者
罗毅
张烈辉
赵玉龙
李成勇
LUO Yi;ZHANG LieHui;ZHAO YuLong;LI ChengYong(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China;School of Energy Resource, Chengdu University of Technology, Chengdu 610059, China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2018年第5期465-472,共8页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:51534006
51374181)资助项目
关键词
裂缝岩心
致密气藏
非稳态测试理论
参数分析
fractured core
tight sandstone gas reservoirs
unsteady testing theoretical
parameter analysis
