Petroleum Production Systems

Chapter 12. Pump-Assisted Lift

12.1. Introduction

Downhole pumps are a common means of boosting the productivity of a well by lowering the bottomhole flowing pressure. Rather than lowering the pressure gradient in the tubing to reduce the bottomhole pressure, as is the case for gas lift, downhole pumps increase the pressure at the bottom of the tubing a sufficient amount to lift the liquid stream to the surface. In fact, the pressure gradient in the tubing is actually higher in a pumped well than it would be without the pump because most of the gas produced with the liquids is vented through the casing-tubing annulus. Furthermore, much of the free gas in the bottom of the well would be redissolved in oil at the higher pump outlet pressure, increasing ...