Downhole tool
AssigneeChurchill Drilling Tools Limited
InventorAndrew Churchill
Life of this patent
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Abstract
A downhole tool (10) comprises a body (12) defining a bore. The body includes a valve arrangement (18) including flow ports (24) in the wall of the body. The ports may be opened or closed. In addition, a variable flow restriction (30) is provided in the bore (14), the degree of restriction tending to decrease as flow across the restriction increases. The variable flow restriction may be utilised to actuate the valve arrangement.
Claims84
A downhole tool comprising:
- a body defining a bore and comprising a valve arrangement including at least one flow port in the wall of the body and whereby the port may be selectively opened and closed;
- and
- a variable flow restriction in the bore, the degree of restriction tending to decrease as flow across the restriction increases.
The tool of any of the preceding claims, wherein the body is adapted to be incorporated in a string of tubing.
The tool of any of the preceding claims, wherein the variable flow restriction is adapted to create a pressure differential and the resulting force utilised to actuate the valve arrangement.
The tool of any of the preceding claims, wherein the valve arrangement is biased towards an open configuration.
The tool of any of the preceding claims, wherein the valve arrangement is initially retained in one of an open configuration and a closed configuration.
The tool of any of the preceding claims, wherein the valve arrangement includes control means for at least one of controlling the sequence of operation of the valve arrangement and controlling the response of the valve arrangement to actuation forces.
The tool of any of the preceding claims, wherein the valve arrangement is flow-actuated.
The tool of any of the preceding claims, wherein the variable flow restriction features a tight configuration in which the restriction substantially closes the body bore.
The tool of any of the preceding claims, wherein the variable flow restriction is positioned upstream of the flow port.
The tool of any of the preceding claims, wherein the variable flow restriction is integral with the body.
A method of controlling flow between a tubular downhole string and a surrounding annulus, the method comprising:
- providing a valve arrangement in a tubular downhole string, the valve arrangement having a flow port providing fluid communication between the string bore and the surrounding annulus and a variable flow restriction;
- pumping fluid through the string;
- selectively opening and closing the flow port;
- and
- increasing the flow rate through the flow restriction to decrease the degree of restriction provided by the flow restriction.
The method of any of the preceding claims, comprising providing the variable flow restriction as a separate unit and dropping the unit into the body.
A fluid-actuated tool comprising:
- a body comprising a valve arrangement including at least one flow port in a wall of the body and whereby the port may be selectively opened and closed;
- and
- a flow restriction operatively associated with the valve arrangement and upstream of the at least one flow port whereby fluid flow through the restriction creates a valve-actuating force and whereby the flow restriction has a variable, flow-related configuration.
A method of controlling fluid flow in a downhole tubular string comprising:
- Providing a valve arrangement in a string, the valve arrangement including a flow port providing fluid communication between the strings bore and the surrounding annulus;
- providing a flow restriction in the string upstream of the flow port;
- flowing fluid flow through the restriction to actuate the valve arrangement;
- and
- varying the configuration of the restriction.
A tool comprising a body including a fluid actuated device including a flow restriction whereby fluid flow through the restriction creates an actuating force and whereby the flow restriction has a variable, flow-related configuration.
Dependencies are inferred from the claim text.