Method and apparatus for variable speed control of oil well pumping units
US5251696A · kind A · utility
Inventors
Key dates
| Filing date | Apr 6, 1992 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Apr 6, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B2201/0202
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for Varying the speed of operations of an oil well pumping unit powered by a motor wherein variations in oil viscosity may be efficiently accommodated. An oil well pumping unit which includes a submersible pump actuated by means of a reciprocating string of sucker rods is monitored for both rod position and load present on the sucker rods. The oil well pumping unit is driven by an electric or gas motor through a controllable coupling and the speed of the oil well pumping unit is then varied, utilizing the controllable coupling, in response to variations in sucker rod load. As the lowering of the sucker rod is impeded by high viscosity oil, the load on the sucker rod decreases. This decrease in sucker rod load is utilized to decrease the speed of the oil well pumping unit by means of the controllable coupling to ensure that bridle separation does not occur. Additionally, increases in sucker rod load above a preselected maximum may also be detected and utilized to slow the operation of the oil well pumping unit to prevent damage to the sucker rods.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.