Abstract: The present invention is used in conjunction with a multi-channel system of a production string for deployment in gas, condensate or oil wells. An end-piece is placed at the entrance to such multi-channel system. It includes a semi-enclosed space helping to increase the proportion of gas phase entering the system at its bottom entrance. Increased proportion of gas allows lifting liquids and/or solids from the wellbore with greater efficiency. Examples of using the invention include wellbore water removal for gas wells with liquid loading problems, for solution gas drive or gas cap driven oils wells during their initial “natural flowing phase”, or during gas re-injection or gas-lift recovery operations for oil wells. It can also be used for gas-lifting water in water wells.

Abstract: A method and apparatus to reduce the axial thrust in rotary machines such as compressors, centrifugal pumps, turbines, etc. includes providing additional peripheral restrictive means (7) attached at the peripheral portion of the disk forming the subdividing means (4) on the side facing the rotating rotor (2). An additional ring element at the periphery of the subdividing means forms additional radial (11) and axial restrictive means (15). Such peripheral restrictive means (7, 11 and 15) function as sealing dams, which combined with the outward flow induced by the rotating impeller, form self-pressurizing hydrodynamic bearings in the axial and radial planes, improving rotordynamic stability. Additionally, a stationary ring element in the center of the cavity forms a seal with the rotor, reducing leakage to suction.

Abstract: A method and device for reducing or eliminating axial thrust in a rotary machine such as a centrifugal pump or compressor by altering the fluid pressure in a cavity formed between a rotor and a housing. The device contains a disk placed along the rotor for subdividing the fluid in the cavity in such a way that all annular gap leakage flow is channeled and pumped through the space between that disk and the rotor from the center of the pump towards the periphery. As a result, the pressure in the cavity is altered to reduce and control the axial thrust on the rotor which becomes independent of the wear state of the shaft seals. In another embodiment, the step of flow subdividing is achieved by providing a set of braking vanes along the periphery of the cavity for reducing the rotational speed of the fluid coming from the cavity as well as from the annular gap and a stationary disk placed along the interior wall of the housing for directing the radial flow of that fluid towards the center of the pump.