THE STUDY OF TWO PHASE NON-LINEAR FLOW IN LOW PERMEABILITY RESERVOIR
低渗透油藏非线性两相渗流研究

Darcy formula is not valid for flows in low permeability reservoirs, due to the obvious non-linear characteristics of the flows. Based on the experiment data of low permeability core, a non-linear formula with two parameters is proposed in this paper. Combining with the Buckly-Leverett formula, non-linear displacement formula is obtained. From the solution of the displacement formula, is compared with the linear flow, it is seen that the displacement efficiency of non-linear flow is lower, the water cut is higher with the same $s_{\rm w}$, especially, and the pressure gradient is bigger, which means the higher injection/production pressure difference. So, smaller well distance and higher injection/production pressure difference are needed for effectively developing low permeability reservoirs.