分流动单元确定储层单相启动压力梯度方法

A model for single phase threshold pressure gradient based on flow units in low permeability reservoirs

针对大多数低渗透储层的渗流规律研究,没有考虑岩石孔隙结构对启动压力梯度的影响,无法取得启动压力梯度平面分布规律的问题,从低渗透储层流动单元的划分出发,将储层划分为A,B,C,D,E五类流动单元.在此基础上,结合启动压力梯度的测试,通过对实验数据的处理和理论分析,建立一种求解单相启动压力梯度的新方法,并建立单相启动压力梯度和流动层段指标的关系表达式.计算5类流动单元单相启动压力梯度的分布范围及平均值,绘制小层上单相启动压力梯度的平面分布图.结果表明,在不同类型的流动单元内确定储层的启动压力梯度,准确度更高,且较好地反映储层非均质性.

In view of the fact that most researches into the flowing laws in low permeability reservoirs have been carried out without due consideration of the effect of rock porosity structure on threshold pressure gradient,and as a result,unable to achieve the distribution law of threshold pressure gradient,in this paper,first of all,from the division of low-permeability reservoir flow units,the reservoirs will be divided into five mobile units,which are A,B,C,D and E.On this basis,combining the test of threshold pressure gradient,through the ptocessing of experimental data and the theoretical analysis,we set up a new model for calculating single phase threshold pressure gradient and established a single-phase threshold pressure gradient and relational expression of flow zone indicator.With the new model mentioned above,this paper calculates the distributing area and average value of single phase threshold pressure gradient in five types of flow units,and protracts the plane distributing map of single phase threshold pressure gradient of small layers.In different types of flow units,the threshold pressure gradient of the reservoir has higher accuracy,and it can reflect the heterogeneity of the reservoir better.