A Dynamic Wellbore Modeling for Sinusoidal Horizontal Well Performance With High Water Cut

摘要

The Banzala Field (Block 0, Angola) has produced oil with horizontal wells and ESP's as the artificial lift method for more than seven years. These wells were drilled with large sinusoidal undulations intentionally to cut the pay section a number of times. Banzala “A” horizontal wells underperformed expected production, possibly due to downhole slugging. In addition, declining reservoir pressures, rising GOR, and rising water-cut have also adversely affected production. The objective of this simulation study of wellbore transient flow is to understand past production performance and to find ways to mitigate adverse well behavior. Simulation showed that low ESP efficiency could be related to down-hole slugging. GOR was the most significant factor for slugging and increasing water cut made slugging worse. The sinusoidal wellbore trajectory was studied to optimize ESP operating conditions. It was found that reducing sinusoidal amplitude by half and flattening the heel-end entrance angle from 79 deg. To 86 deg. Would suppress slugging significantly.