Well control
AssigneeWeatherford/Lamb, Inc.
InventorGiancarlo Tomasso Pietro Pia
Life of this patent
Estimating the term…
Abstract
A method of isolating a reservoir of production fluid in a formation comprises providing a pair of valves (14, 16) in a bore intersecting a production formation and in which the hydrostatic pressuer in the bore at the formation is normally lower than the formation pressure, and then ontrolling the valves (14, 16) from surface such that the valves (14, 16) will only move from a closed configuration to an open configuration on experiencing a predetermined differential pressure across the valves.
Claims58
A method of isolating a reservoir of production fluid in a formation, the method comprising:
- providing a valve in a bore intersecting a production formation and in which the hydrostatic pressure in the bore at the formation is normally lower than the formation pressure;
- and
- controlling the valve from surface such that the valve will only move from a closed configuration to an open configuration on experiencing a predetermined differential pressure thereacross.
The method of any of the preceding claims, wherein the closed valve is controlled to hold higher pressure above the valve.
The method of any of the preceding claims, wherein the closed valve is controlled to hold higher pressure below the valve.
The method of any of the preceding claims, wherein the closed valve is controlled to hold pressure from both sides.
The method of any of the preceding claims, wherein the valve is positioned above the pressure balance point in the bore.
The method of any of the preceding claims, wherein the valve is controlled from surface by fluid pressure.
The method of any of the preceding claims, wherein the control fluid supply is supplied from surface to the valve through at least one control line.
The method of any of the preceding claims, wherein the valve is initially open and comprising the step of applying a selected first control pressure to close the valve.
The method of any of the preceding claims, comprising providing two similar valves in the bore.
The method of any of the preceding claims, comprising running the valve into a cased bore on intermediate or parasitic casing, thus defining a parasitic annulus between the existing casing and the parasitic casing.
The method of any of the preceding claims, further comprising locking the valve open.
An apparatus for use in isolating a reservoir of production fluid in a formation, the apparatus comprising:
- a valve adapted for location in a bore intersecting a production formation and in which the hydrostatic pressure in the bore at the formation is normally lower than the formation pressure;
- first valve control means for permitting control of the valve from surface;
- and
- second valve control means for permitting control of movement of the valve from a closed to an open configuration in response to a predetermined differential pressure across the valve.
An apparatus for use in isolating a reservoir of production fluid in a formation, the apparatus comprising:
- a valve adapted for location in a bore intersecting a production formation and in which the hydrostatic pressure in the bore at the formation is normally lower than the formation pressure;
- and
- first valve control means for permitting control of the valve from surface,
- the valve including two valve closure members, both valve closure members being adapted to hold pressure both from above and from below.
Dependencies are inferred from the claim text.