摘要
低渗透油藏非达西渗流动边界的产生归因于启动压力梯度。在考虑动边界的基础上,建立包含表皮效应和井筒存储的单一、以Warren-Root模型为基础的双重和三重介质低速非达西渗流数学模型;并通过定义无量纲压力得到模型的Laplace解,利用Stehfest数值反演获得动边界的传播规律,对比动边界与无限大、封闭及定压等三类外边界条件下的压力及压力导数分布特征。结果表明:对于低速非达西渗流,启动压力梯度越大,动边界向外传播越慢;在双重介质和三重介质中,动边界移动出现短暂的停滞,曲线上表现为水平段或平缓段;动边界主要影响压力及压力导数曲线的中后期,而无限大、封闭及定压等三类外边界主要影响曲线的后期形态。
The moving boundary is caused by threshold pressure gradient in non-Darcy flow for the low permeability reservoirs.Considering the moving boundary,and combining the skin effect and wellbore storage,the mathematical models of non-Darcy flow with low velocity were established in single-porosity,dual-porosity and triple-porosity porous media according to Warren-Root model.The Laplace analytical solution was obtained by defining dimensionless pressure,and the movement characteristics of moving boundary was described using the method of Stehfest numerical inversion.Moreover,distribution curves of the pressure and the pressure derivate with moving boundary were compared with those of infinite boundary,closed boundary and constant pressure boundary.The results indicate that,the bigger the threshold pressure gradient is,the more slowly the moving boundary propagates.The movement of the moving boundary stops for a very short time in dual-porosity and triple-porosity porous media,and the curve of moving boundary is horizontal or a slope with small angles.The distribution of pressure and pressure derivate is mainly affected by the moving boundary in the middle and later stages of theprocess,but the other three boundaries change the shape of pressure and pressure derivate curves in the final stage.
出处
《东北石油大学学报》
CAS
北大核心
2016年第2期71-77,125-126,共7页
Journal of Northeast Petroleum University
基金
国家科技重大专项(2011ZX05016-006)
中央高校基本科研业务费专项资金项目(35832015034)
关键词
非达西渗流
启动压力梯度
动边界
单一介质
双重介质
三重介质
non-Darcy flow
threshold pressure gradient
moving boundary
single-porosity media
dual-porosity media
triple-porosity media
