Submerged motor-pump unit
US4477235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1983 |
| Grant date | Oct 16, 1984 |
| Priority date | — |
| Expiry date | Mar 30, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K5/132
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor-pump unit for submerging down a well, e.g. an oil well, comprises a motor portion driving a pump portion. The motor portion is filled with fluid to prevent ingress of the surrounding medium which the pump portion pumps. The fluid is maintained at a higher pressure than the surrounding medium by including a flexible tank filled with fluid and in communication with the fluid in the motor portion. The flexible tank is compressed both by the surrounding medium and by resilient compression means so that the pressure inside the motor is higher than the surrounding pressure, thereby ensuring any leakage is outwardly from the motor. Down the well the temperature rises causing the fluid to expand, so the flexible tank is left substantially empty when the unit is prepared at the surface prior to lowering. If a large rise in temperature is to be expected, a resilient compression means which provides adequate excess pressure near the top of the well as the unit is lowered, will provide too much excess pressure at operating depths, and similarly compression means which provide adequate excess pressure at operating depths do not supply enough near the surface. This problem is solved by p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.