Benefits of Electrical Submersible Pumping in a Production by Gas-Alternating-Water Recovery Process

Abstract

Abstract Using Electric Submersible Pumps (ESP) in a reservoir undergoing miscible gas and water injection for Enhanced Oil Recovery (EOR) purpose allowed increasing oil recovery beyond gas and water injection process and reducing the time to deplete the reservoir. The reservoir pressure is above the minimum miscibility pressure (MMP) for the entire simulation and the saturation pressure was lower than MMP Two cases have been compared which are: 1-Well controlled by minimum tubing head pressure (THP) of 1000psia and 2-Well controlled by minimum Bottom-hole-pressure (BHP) which is simulates an Electrical submersible pump (ESP) installed. The minimimum bottom-hole-pressure of 500psia has been used to model the ESP. The electrical submersible pump has been simulated in the reservoir model by maintaining the minimum BHP of 500psia to maximize the oil production of 25000stb/d. Due to flow rate variation during the lifetime of the well, pump frequency varied operating in the range of 35Hz to 85Hz but for short period of time on these extremes. Simulation time on THP and BHP control modes were 2000days and 3000days respectively. Oil recovery without and with ESP were 84% and 88% respectively. Due to fact that the reservoir fluid is light oil in addition to gas injection process, the pump sizing and selection has been presented to be a challenge due to high Gas Oil Ratio (GOR). Using ESP in gas and water injection process can be advantageous in developing marginal fields where there a need to produce it in short time to maintain the operating costs low but CAPEX can be high.