低渗透介质有启动压力梯度的不稳态压力分析  

Pressure transient analysis in low-permeable media with threshold gradients

作　　者：王晓冬[1] 侯晓春[1] 郝明强[2] 杨涛[1] 

机构地区：[1]中国地质大学能源学院,北京100083 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油学报》2011年第5期847-851,共5页Acta Petrolei Sinica

基　　金：国家科技重大专项(2009ZX05009-004-03)资助

摘　　要：在低渗透油藏中,考虑启动压力梯度的流体不定常渗流存在动边界,其传播规律直接反映了储层的动用范围,并对压力动态影响明显。运用数理方法求解了包含启动压力梯度、有动边界存在的非线性不定常渗流数学模型,得到了新的压力分布和动边界传播规律解析解。计算分析表明,启动压力梯度越大,动边界传播越慢,压力损失越大。井壁压力在中后期不会表现出平面径向渗流特征,并运用Duhamel褶积建立了相应的现代试井分析典型曲线图版。In low-permeability reservoirs,there exists a moving boundary in the transient seepage flow of fluids when the threshold pressure gradient is considered.Transmission rules of the moving boundary may directly reflect the producing scope of a reservoir and affect pressure behaviors significantly.A nonlinear mathematical model for the transient seepage flow including the threshold pressure gradient and moving boundary was established using advanced mathematical methods,and a novel analytical solution to pressure distributions and transmission rules of the moving boundary was acquired.Calculation analyses indicated that the greater the threshold pressure gradient,the slower the transmission of the moving boundary and the more the pressure loss.The pressure of well walls was not characteristic of radial fluid flow at the middle and late stages.Typical curves for the modern well test analysis were obtained by means of the Duhamel convolution theory,and field test data were interpreted as well.Some applicable approaches of the study result were demonstrated by case analyses.

关 键 词：启动压力梯度 动边界 不定常渗流 不稳态压力分析 低渗透油藏 

分 类 号：TE312[石油与天然气工程—油气田开发工程]