| 摘要 |
<p>A downhole gas compression system for location in a bore includes an axial flow compressor 32 and a gas-filled electric drive motor 30. The system may include valves (62, figure 2) which permit gas from the motor to vent into the bore 12 but which prevent flow in the opposite direction. Preferably, the motor is both gas lubricated and gas cooled and both the motor and the compressor may further include gas lubricated bearings (56-61, figure 2). Preferably, the motor drives the compressor directly on a single shaft and may be a high frequency, variable speed, permanent magnet motor adapted to be driven at high speed, for example 20,000 to 70,000 rpm. The gas may be supplied to the motor and compressor from either the surface or directly from the wellbore and means are preferably provided for removing solids or liquids from the gas.</p> |
