A New Completion Methodology to Improve Oil Recovery for Horizontal Wells Completed in Highly Heterogeneous Reservoirs

Abstract

The specific inflow distribution along the horizontal wellbore is significantly uneven in highly heterogeneous reservoirs. Such uneven influx is recognized as the cause of early water breakthrough, poor oil sweep efficiency and low ultimate recovery. Interval control valves (ICVs) are practical completion hardwares that can actively equalize the contributions from all controlled zones. However, the wellhead penetration limitation impedes ICVs’ application in highly heterogeneous reservoirs, which require many control intervals. This paper proposes a new completion methodology that combines ICVs and variable-density perforations (ICVs + VDP) to eliminate the limitation of ICVs applied in highly heterogeneous reservoirs. The ICVs + VDP completion can achieve more subtle controls because VDP is capable of reducing the inflow difference in each subzone. A steady-state modeling approach and a transient-state modeling approach are used to evaluate the effect of the ICVs + VDP completion on inflow equalization and well performance optimization. The observations from case study show that horizontal wells with the ICVs + VDP completion can considerably delay water breakthrough, improve oil recovery, and reduce water production in highly heterogeneous reservoirs.