大量实验表明气体在低渗透气藏中渗流存在启动压力梯度。由于气体渗流的启动压力梯度难以直接测定,目
前大多通过低压下低速渗流实验,测量气体渗流速度,建立气体渗流速度与压力平方差的关系,根据其非线性特征求
解气体渗流的启动压力梯度。但低压下气体滑脱效应的影响在地层条件下几乎不存在,因此,这种方法求得的启动压
力梯度值与实际值存在偏差。为了更准确地确定气体启动压力梯度值,提出了一种消除滑脱效应确定气体启动压力
梯度的新方法,该方法确定的启动压力梯度为低渗透气田的合理有效开发提供了更为准确的依据。
Many experiment results show that there exists a threshold pressure gradient when gas is percolating in low permeability reservoir. As it is difficult to directly determine the threshold pressure gradient,the low-pressure and low-velocity percolation experiment is the usual method used to obtain the threshold pressure gradient. However,the effect of gas slippage under low pressure does not work under the formation condition. Thus there exist differences between the threshold pressure gradient value obtained by Wufan’s method and the actual results. In order to get a more accurate value of threshold pressure gradient,a new method which eliminates the slippage effect is presented this paper and provides a more accurate threshold pressure gradient for developing low-permeability gas fields.
摘要:
大量实验表明气体在低渗透气藏中渗流存在启动压力梯度。由于气体渗流的启动压力梯度难以直接测定,目 前大多通过低压下低速渗流实验,测量气体渗流速度,建立气体渗流速度与压力平方差的关系,根据其非线性特征求 解气体渗流的启动压力梯度。但低压下气体滑脱效应的影响在地层条件下几乎不存在,因此,这种方法求得的启动压 力梯度值与实际值存在偏差。为了更准确地确定气体启动压力梯度值,提出了一种消除滑脱效应确定气体启动压力 梯度的新方法,该方法确定的启动压力梯度为低渗透气田的合理有效开发提供了更为准确的依据。