The Research On Water Drive Ineffective Circling Flow Mechanism Based On Finite Element Method

After entering the later high water cut period，there exist horizon of relatively enrichedremaining oil and also ineffective injection-production placement consist of high capacitychannel in reservoirs. Therefore, confirming the distribution of water drive ineffectivecircling is very important for EOR during the high water cut period development adjustment.In this paper, a finite element numerical simulation method of three-dimensional oil andwater phase flow was established according to water drive ineffective circling seepageproblem. On the basis, the influences of vertically heterogeneous medium and main streamline on water drive ineffective circling was studied. The simulation results of performancecurve, saturation and flow line distributing graph were analyzed and compared. With certainwell spacing，the occurring of water drive ineffective circling in homogeneous formation wasslower than that in formation with high permeability layer. And water drive ineffectivecircling area mainly concentrated in the high permeability layer and the bottom of oilformation. The influence of plane homogeneous anisotropy on water drive ineffective circlingwas not obvious. And the water drive ineffective circling was obvious when regionalpermeability was quite different from formation permeability. The stronger formationheterogeneity was, the lower degree of reserve recovery would be.This study provides atheoretical basis for oil field development adjustment later, is a new way of the study of waterflooding invalid circulation.