Multiphase-Pump Field Trials Demonstrate Practical Applications for the Technology

Abstract

Summary This paper presents the results of two multiphase-pump field trials. One field trial was conducted offshore on a platform in the Gulf of Mexico (GOM). It is a low-pressure boost (100 psi) application involving gas-lifted wells. The other field trial was conducted onshore in an oil field in Alberta, Canada. This multiphase pump was designed for a high-pressure boost (850 psi) capability with primarily rod-pumped wells feeding the suction of the pump. The offshore pump was sized to handle the flow from one well. By lowering the back pressure on the well, increased production was realized. The increased flow from one of the wells far surpassed the predicted quantity. Early problems with the double mechanical seal system were overcome and a new, simplified single mechanical seal system has been designed and installed. The onshore multiphase pump clearly demonstrated that a twin-screw pump can operate reliably in a field environment, even under severe slug flow conditions. The trial indicated that a considerable portion of the liquid in the recycle stream (required because of the high gas fraction of the multiphase fluid from the field) flashes into gas, which occupies more volume in the pump than if it remained liquid. This decreased the capability of the pump to handle net flow from the field. These conditions motivated a re-evaluation of the pump-sizing techniques. Performance data and lessons learned information are presented for both field trials.