Flow control sub for hydraulic expanding downhole tools
AssigneeSmith International, Inc.
InventorBruce D. Swearingen
Life of this patent
Estimating the term…
Abstract
A hydraulic control sub assembly for actuating hydraulically operated downhole remedial tools, such as section mills or underreamers, is disclosed. The control sub features a drop ball mechanism to terminate the flow of drilling fluid to the hydraulic tool thereby inactivating the tool. The control sub also has a hydraulic rupture disc that permits drilling fluid circulation when tripping the drill pipe. The control sub further contains upwardly directed jet nozzles to enhance fluid flow in the well bore to help clear away debris. A float valve is also incorporated in the control sub to ensure there is no fluid under high pressure trapped in the hydraulic tool that may jam the tool.
Claims9
A flow control sub assembly for hydraulically activated tools utilized in downhole operations performed in well boreholes comprising;
- a cylindrical sub assembly housing forming a first upstream end and a second downstream end, said housing being threadably connected between a drill string at its first upstream end and a tool at its downstream end, said housing forming a means partially contained within said housing, intermediate said first and second ends, to stop at least a portion of a hydraulic fluid flow to said tool to inactivate said tool and to divert said fluid within said housing to an annulus formed between said housing and a wall of a borehole thereby providing a high volume of fluid around said inactivated tool to continually remove detritus from said downhole operations and to help prevent said tool and said flow control sub assembly from becoming stuck in the borehole as said drill string is removed from said borehole wherein said means to stop said portion of said flow to said tool and to divert said fluid portion to said annulus surrounding said sub assembly is a plug device positioned above said tool and a burst disc positioned in a wall formed by said housing between said plug device and said first end of said sub assembly housing, said plug device, when activated, stops said portion of the fluid flow to said tool and hydraulic fluid under increased pressure from a pump means bursts said disc at a predetermined pressure drop across said disc thereby diverting said fluid to said annulus.
A flow control sub assembly for hydraulically activated remedial tools utilized in downhole operations in well boreholes comprising;
- a cylindrical sub assembly housing forming a first upstream end and a second downstream end, said housing being threadably connected between a drill string at its first upstream end and a remedial tool at its downstream end, said housing forming a means partially contained within said housing intermediate said first and second ends, to divert a portion of a hydraulic fluid flow pumped down said drill string by a pump means toward said remedial tool exteriorly of said housing into an annulus formed between said housing and a borehole to aid in the removal of debris from said borehole during operation of said remedial tool in said borehole wherein said means to stop said portion of said flow to said tool and to divert said fluid portion to said annulus surrounding said sub assembly is a plug device positioned above said tool and a burst disc positioned in a wall formed by said housing between said plug device and said first end of said sub assembly housing, said plug device, when activated, stops said portion of the fluid flow to said tool and hydraulic fluid under increased pressure from a pump means bursts said disc at a predetermined pressure drop across said disc thereby diverting said fluid to said annulus.
Dependencies are inferred from the claim text.