油层内非线性渗流分布区域确定方法

 针对非线性渗流对应的压力梯度范围以及油层内的分布区域进行了研究.依据实验确定最小启动压力梯度,结合最小启动压力梯度、最大启动压力梯度与喉道半径的关系,提出了先计算极限剪切应力,然后再计算最大启动压力梯度的方法.通过回归分析得到非线性渗流对应的压力梯度范围,该压力梯度范围与注采井间压力梯度剖面相耦合,即可得到油层中非线性渗流分布区域,两个井组的实例分析表明,非线性渗流分布区域与油井动态吻合,从而证明该方法可行.根据注采井间压力梯度分布计算公式,提出了新的极限注采井距确定方法,对开发方案中注采井距的确定具有重要意义.

Nonlinear Percolation Area Distribution in a Reservoir

The maximum starting pressure gradient and the nonlinear percolation area distribution are studied based on the low rate non-Darcy flow. From the minimum starting pressure gradient obtained from experiments and the relationship between the starting pressure gradient and the throat radius, the limit shear stress and the maximum starting pressure gradient are obtained. The range of the nonlinear percolation area pressure gradient is determined by using a regression analysis. When the pressure gradient range is related with the pressure gradient distribution, the nonlinear percolation area distribution range can be obtained. Two well group examples show that the nonlinear percolation area distribution range thus obtained is consistent with the oil well dynamics. The method is shown to be practicable. A new method to calculate the limit injection production well spacing is proposed according to the injection production pressure gradient distribution and can be used for calculation of the injection production well spacing in an oilfield development plan.