动边界影响的低渗双重介质油气藏试井解释模型  

STUDY OF WELL-TEST MODEL OF LOW PERMEABILITY'S DUAL-PORE MEDIA WITH FLOWING BOUNDARY IN OIL AND GAS

作　　者：刘启国[1] 杨旭明[2] 魏红梅[3] 李允[1] 张烈辉[1] 

机构地区：[1]"油气藏地质及开发工程"国家重点实验室(西南石油学院),四川成都610500 [2]四川石油地调处 [3]长庆油田第二采油厂

出　　处：《西南石油学院学报》2004年第5期30-33,共4页Journal of Southwest Petroleum Institute

基　　金：四川省学术和技术带头人培养基金项目 (2 2 0 0 32 0 )

摘　　要：从低渗透油气藏的开发以及试井工作的实践可知 ,低渗透油藏中流体的渗流存在启动压力梯度 ,试井曲线往往表现为不易出现径向流直线段或不出现径向流直线段 ,其压力波传播的特点是流体动边界不断向外扩展。针对这种情况 ,首先建立了考虑井筒储存和表皮效应影响的低速非达西渗流定产量生产的固定边界数学模型 ,用格林函数法求出了井底压力的拉普拉斯空间解 ;然后根据流体从静止到流动所需的启动压差确定不同时刻的动边界半径 ,再用固定边界模型计算井底压力与时间的关系 ,以此作为动边界模型的一种数值逼近。用Stehfest数值反演算法绘制了井底无因次压力与无因次时间关系曲线 ,讨论了动边界、启动压力梯度。According to the practice of exploitation and well testing in low permeability reservoirs, the fluid flow had the starting pressure gradient in low permeability reservoirs. The well test curves are not easy to show the radius flow straight lines. a feature of pressure propagation with low velocity non-darcy percolation is that the fluid flowing boundary extends outwards continuously. In views of this situation, a fixed boundary mathematical model based on the pattern of low velocity non-darcy percolation with wellbore storage and skin effect was presented, and solutions of wellbore pressure in Laplace domain was solved with Green's function. The radiuses of flowing boundary corresponding to the different time were determined in accordance with the starting differential pressure by fluid from static to flowing condition, analytical solution of fixed boundary model was then used to calculate the correction of wellbore pressure varied with time, which was regarded as a numerical approximation of flowing boundary model. The curves of the wellbore pressure varied with time were developed by Stehfest reverse method, and the influences of flowing boundary, starting pressure gradient, storage ratio, inter porosity flow coefficient and difference between darcy percolation and non-darcy percolation were discussed in details.

关 键 词：低渗透油气藏 非达西渗流 启动压力梯度 流动边界 试井解释 井储和表皮 

分 类 号：TE353[石油与天然气工程—油气田开发工程] TE319