Abstract: A pump assembly particularly for use in high pressure operations is disclosed, which pump assembly is a barrel casing cartridge pump assembly which includes a pump cartridge having a plurality of impeller stages, and a barrel body casing which encases a portion of the pump cartridge. The barrel casing includes a centrally located suction branch which directly feeds a first impeller stage which is located centrally of the pump cartridge. Each impeller of the pump cartridge includes an eye for receiving fluid, the arrangement being such that each eye faces towards the suction branch.

Abstract: It is common in oil extraction operations to reinject produced gas and\or water back into hydrocarbon bearing formations in order to maintain formation pressure. Conventional production facilities normally flow all formation fluids to the surface and subsequently reinject the required fluids back into the formation, which can be extremely inefficient due to the high power input required to overcome the large pressure differential between the surface and formation level. A production fluid handling method and apparatus for separating downhole at least gaseous and liquid components (16, 18, 20) of fluid produced from a hydrocarbon bearing formation (12), and reinjecting at least a portion of the gaseous and liquid components (16, 18, 20), as required, back into the formation (12). Re-injection also occurs downhole.

Abstract: A downhole gas compression system is adapted for location in a bore of a natural gas-producing well (10), the system comprising an axial flow compressor (32) and a gas-filled electric drive motor (30). The motor drives the compressor to compress the produced gas, the compressed gas being directed upwardly through production tubing (20) to surface.

Abstract: A pump assembly particularly for use in high pressure operations is disclosed, which pump assembly is a barrel casing cartridge pump assembly which includes a pump cartridge having a plurality of impeller stages, and a barrel body casing which encases a portion of the pump cartridge. The barrel casing includes a centrally located suction branch which directly feeds a first impeller stage which is located centrally of the pump cartridge. Each impeller of the pump cartridge includes an eye for receiving fluid, the arrangement being such that each eye faces towards the suction branch.

Abstract: A multistage pump or compressor includes a series of axial flow stages. Each stage comprises an impeller for imparting whirl to the pumped fluid in one direction and a stator including vanes for imparting whirl to the pumped fluid in the opposite direction. The stator vanes define flow passages configured such that the fluid flows through the passages at substantially constant absolute velocity. The average ratio of stage axial length to impeller diameter for each axial flow stage is less than 0.4.

Abstract: A multistage axial flow pump or compressor comprises at least one stage (10) including a rotor (16) and a stator (20). The rotor (16) is arranged to impart whirl in one direction, while the stator (20) is arranged to impart whirl in the opposite direction. This arrangement is useful in providing comparatively high stage pressures for a given rotor tip velocity with relatively low rotor vane hydraulic loadings. The arrangement is also useful in pumping multiphase fluids.

Abstract: A pump for low head duties includes an impeller portion and a diffuser portion which together define the entire liquid retaining and guidance means between the inlet and the outlet, the impeller serving to raise liquid from a lower reservoir and having a plurality of spiral passages therethrough in which, in operation, a free liquid surface vortex is enabled to form, the diffuser portion leading from the impeller outlet having a rotatable section and an upwardly increasing diameter. The impeller comprising vanes having leading edges extending downwardly and outwardly to provide a liquid inlet providing a substantially unobstructed entry to the vanes and automatic control of the quantity of liquid pumped according to the level of liquid in the lower reservoir. The diffuser portion is driven separately at a speed less than the impeller.

Abstract: In a rotodynamic pump intended for operation at high pressures e.g. 2000 p.s.i. and for pumping contaminated fluids e.g. corrosive water, high pressure sealing assemblies are provided at the through-openings in the pump casing for the pump shaft. Each assembly includes a pair of axially spaced mechanical seals, and each seal comprises a rotor portion fixed to the pump shaft and a stator portion axially movable into sealing engagement with the rotor portion, the stators being located intermediate the rotor portions. A busing is located between the seals and includes conduits supplying oil at a pressure above pump pressure to the innermost seal whence the oil is reduced in pressure and passed to the outermost seal, so that oil is delivered to the facing ends of the stators. The oil serves for lubrication of the sealing interfaces and for the prevention of egress of contaminated material through said innermost seal.

Abstract: A centrifugal fluid pump includes a casing housing an impeller having a suction eye, an axial fluid inlet to the impeller eye, a fluid discharge, and a recirculation line for recycling leakage liquid from the casing to the fluid inlet to minimise the risk of cavitation occurring at the impeller eye. A heat exchanger is located in the recirculation line for cooling the recycled leakage liquid and has control means associated therewith. The recycled liquid is introduced by a duct into the fluid inlet close to the impeller eye with an axial component of flow so that disturbance to flow in the inlet is reduced. In particular, the recirculation line may discharge into an annular velocity stabilising chamber at the fluid inlet, and a frusto-conical passage delivers the liquid from the chamber to the fluid inlet.