Wells – Processes – Cleaning or unloading well
Reexamination Certificate
1999-11-10
2001-04-17
Tsay, Frank (Department: 3672)
Wells
Processes
Cleaning or unloading well
C166S105100
Reexamination Certificate
active
06216788
ABSTRACT:
TECHNICAL FIELD
This invention relates to a method and apparatus for removing sand that collects below an electrical submersible pump in a well. In particular, the invention relates to a method and apparatus for separating sand from well fluids and then pumping the separated sand to the surface.
BACKGROUND ART
Electrical submersible pumps are widely used in oil wells. It is desirable to remove sand and other solid particles from well fluids before they enter the submersible pump since sand causes wear and plugging of the pump and other components. The subsequent repairs or replacement of a downhole pump can be expensive due to labor, parts costs and loss of production.
During oil production from a well, oftentimes sand or other particles that are entrained with well fluids are pumped through the downhole pump. Various sand control systems have been implemented to stop or reduce sand flow into the wellbore. Screens or filter openings have been utilized in the casing or other members to restrict the flow of solid particles. In many wells, the quantity of sand flowing from the formation is relatively small, but is sufficient to wear or plug the downhole pump. One solution is to provide a separator, such as a hydro-cyclone separator to separate sand from well fluids that enter the wellbore.
Once the sand is separated from the fluids, the separated sand will settle out within the wellbore. If large quantities of sand are produced, then it may be necessary to remove sand from the wellbore. Since it is expensive to cease production and pull the electrical submersible pump, it is desirable to utilize a method and apparatus for removal of the sand without pulling the electrical submersible pump.
DISCLOSURE OF INVENTION
An electrical submersible pump (ESP) is suspended on a flow conduit within a well. A separator is provided to separate sand from well fluids before the well fluids enter the pump. A bypass tube is connected from the flow conduit above the pump to a location below the pump where the sand is collected. The electrical submersible pump may be turned off to allow fluid levels within the flow conduit to equalize. The flow conduit is then pressurized at the surface to cause a downward flow of well fluid in the flow conduit below an equilibrium point for the well fluid. After lowering the level of fluid within the flow conduit, the pressure within the flow conduit is then relieved, which causes well fluid to flow back up through the bypass tube to the flow conduit. The upward flow of well fluid results in sand being drawn up the bypass tube into the flow conduit above the pump. The fluid and sand are routed through the bypass tube rather than through the pump since the flow path through the pump is obstructed. A check valve in the bypass tube prevents back-flow of sand and fluid through the bypass tube after the sand and fluid have flowed up through the bypass tube into the flow conduit. Once the fluid and sand have flowed into the flow conduit above the pump, the pump may be restarted and the sand and fluid in the flow conduit may be pumped to the surface.
REFERENCES:
patent: Re. 35453 (1997-02-01), Cobb
patent: 3361206 (1968-01-01), Raulins
patent: 3963073 (1976-06-01), Laval, Jr.
patent: 4223724 (1980-09-01), Levoni et al.
patent: 4407360 (1983-10-01), Hamrick
patent: 4621693 (1986-11-01), Caldwell et al.
patent: 4924940 (1990-05-01), Burroughs et al.
patent: 5295537 (1994-03-01), Trainer
patent: 5314018 (1994-05-01), Cobb
patent: 5553669 (1996-09-01), Trainer
patent: 5662167 (1997-09-01), Patterson et al.
Baker Hughes Incorporated
Bradley James E.
Felsman, Bradley, Vaden, Gunter & Dillon L.L.P.
Tsay Frank
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