ELECTRICAL SUBMERSIBLE PUMP ASSEMBLY FOR SEPARATING GAS AND OIL

摘要

An electrical submersible pump assembly for use in a well, including a well having a high gas-to-liquid ratio has a motor (12), a hollow, tubular drive shaft (30) which drives the pump (20), and a liquid-gas separator assembly (32) upstream of the pump intake. The liquid- gas separator has a hollow tubular portion (34), which communicates with the open, lower end of the drive shaft, openings (35) through its sidewall, and a closed lower end. The sidewall also includes at least one outwardly extending projection shaped for urging liquid contained in a liquid/gas mixture flowing towards the pump outwardly, away from the sidewall openings. Preferably, the outwardly extending projection comprises a helical blade (36) which, using either the well casing or a separate sheath, defines a helical channel through which the oil-gas mixture flows prior to reaching the pump intake. The centrifugal force in the channel forces the oil component away from the openings and forces the gas component through the openings into the tubular portion (34) and, where such gas may be vented via drive shaft (30) to the surface.