变形介质低渗透油藏的产能分析

在低渗透油藏中，由于多孔介质孔隙和喉道较小，固液作用显著，因此达西定律已不适应，实验表明，低渗透油藏渗流时存在启动压力梯度，另外，有些低渗透油藏还具有介质变形的性质。尤其是异常高压的低渗透油藏，变形介质的渗透率一般随压力变化呈指数关系，考虑启动压力梯度和介质变形的影响，研究低渗透油藏中直井产量的变化规律，计算表明，低渗透油藏中，油井的产量随启动压力梯度和介质变形系数的增大而减小，随生产压差的增大而增大，对于采油指数，则存在一个最佳压差，此时采油指数最大，在油田的生产中，可通过增大生产压差或者 减小注采井距来提高油井的产量。

Productivity analysis for low permeable reservoirs of media deformation

In low permeable reservoir, solid liquid effect is prominent due to small pore and throat, therefore Darcy's law is unavailable. Experiment shows that start up pressure gradient exists in low permeable reservoir during percolation. In addition, media deformation may occur in some low permeable reservoirs, especially those with abnormal high pressure. It shows an exponential relation between permeability of media deformation and pressure change. With consideration of start up pressure gradient and media deformation, this paper studies vertical well production in low permeable reservoirs. Calculation shows that, in low permeable reservoirs, well production decreases as the increasing of start up pressure gradient and media deformation factor, and increases as the increasing of producing pressure differential. The productivity index is highest under optimum pressure differential. In field practice, well production can be improved by increasing producing pressure differential or reducing well spacing between injectors and producers.