Multiphase Pumps for Minas Light Oil Steam Flood, Sumatra-Indonesia

Abstract

Abstract Multiphase pumps are modified liquid pumps that are capable of pumping various combinations of oil, water, gas, and sand in the same pipeline without separation. Minas Light Oil Steam Flood (LOSF) Pilot Project will utilize the multiphase technology to boost casing fluid with high steam and gas content from wells to the Gathering Station without prior separation. Hence, tremendous savings in capital and operating costs are realized from strategic placement of multiphase pumps since large separators, liquid pumps and compressors are eliminated. Two uniquely different multiphase pumps, a 500 hp twin-screw pump and a 700 hp helico-axial pump, were recently tested and qualified at the Texaco Multiphase Flow Facility, where flow rates as high as 145,000 BPD and gas volume fractions (GVF) up to 100% were achieved. An illustration of each pumping unit is given followed by a presentation of measured performance data relative to the operating conditions chosen by Caltex Pacific Indonesia (CPI). Based on test results, the advantages and disadvantages of the competing technologies are compared, noting that CPI will eventually consider these data to choose either twin-screw or helico-axial technology for the Minas Light Oil Steam Flood project. Results obtained at the Texaco Multiphase Flow Facility indicate that twin-screw pumps are 25% more efficient than helico-axial pumps. Furthermore, twin-screw pumps are virtually insensitive to liquid slugs and large changes in inlet gas density; helico-axial pumps require slug catchers upstream of the pump inlet to absorb these intermittent slugs and large variations in GVF. It is anticipated, however, that helico-axial pumps are superior in resisting long-term wear from continuous exposure of sand, which will be investigated in Duri in the fourth quarter of 1998.