DEEPSET WIRELINE RETRIEVABLE SAFETY VALVE

Abstract

The present invention generally relates to a deepset wireline retrievable safety valve for controlling fluid flow through a production tubing string. In one aspect, a valve for use in a wellbore is provided. The valve includes a housing having a bore. The valve further includes an actuator sleeve movable within the housing between a retracted position and an extended position. The actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing. Additionally, the valve includes a first piston member attached to a first side of the actuator sleeve and a second piston member attached to a second side of the actuator sleeve, wherein wellbore fluid pressure acts on the first piston member, which results in a first force, and acts on the second piston, which results in a second force, and the first force and the second force are applied to the actuator sleeve in an opposite direction.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a valve for use in a wellbore. More particularly, this invention pertains to a deepset wireline retrievable safety valve for controlling fluid flow through a production tubing string.

2. Description of the Related Art

Deep set safety valves are commonly used to shut in oil and gas wells. Such safety valves are typically fitted into production tubing in a hydrocarbon producing well, and operate to block the flow of formation fluid upwardly through the production tubing should a failure or hazardous condition occur.

Deep set safety valves may be configured as rigidly connected to the production tubing (tubing retrievable), or may be installed and retrieved by wireline, without disturbing the production tubing (wireline retrievable). A problem arises when the valve is positioned deep within the wellbore (>6000 feet) because the components in the valve are unable operate due to hydrostatic pressure of the fluid in a control line connected to the valve and the wellbore pressure. There is a need therefore for a deep set safety valve that can withstand the effects of wellbore pressure.

SUMMARY OF THE INVENTION

The present invention generally relates to a deepset wireline retrievable safety valve for controlling fluid flow through a production tubing string. In one aspect, a valve for use in a wellbore is provided. The valve includes a housing having a bore. The valve further includes an actuator sleeve movable within the housing between a retracted position and an extended position. The actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing. Additionally, the valve includes a first piston member attached to a first side of the actuator sleeve and a second piston member attached to a second side of the actuator sleeve, wherein wellbore fluid pressure acts on the first piston member which results in a first force and acts on the second piston which results in a second force. The first force and the second force are applied to the actuator sleeve in an opposite direction.

In another aspect, a valve for use in a wellbore is provided. The valve includes a housing having a bore. The valve further includes an actuator sleeve movable within the housing between a retracted position and an extended position. The actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing. The valve also includes a first piston member attached to a first side of the actuator sleeve. The first piston member is in fluid communication with a control line. The valve also includes a second piston member attached to a second side of the actuator sleeve. The second piston member is in fluid communication with a cavity in the housing. Additionally, the valve includes a biasing member configured to bias the actuator sleeve in the retracted position.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is a view illustrating a safety valve.

FIG. 1A is an enlarged view of the safety valve.

FIG. 1B is an enlarged view of the safety valve.

FIG. 1C is an enlarged view of the safety valve.

DETAILED DESCRIPTION

The present invention generally relates to a deep set safety valve for use in a wellbore. To better understand the novelty of the deep set safety valve of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings.

FIG. 1 is a view illustrating a deep set retrievable safety valve 100. The valve 100 is generally used in a production tubing to selectively control the fluid flow in the production tubing. Typically the valve 100 is lowered in the production tubing until a first end 190 of the valve 100 is placed within a safety valve landing nipple that is connected to a single control line, such as control line 112. The control line 112 supplies fluid to control the movement of an actuation sleeve 105 within a housing 110 of the valve 100. As will be discussed herein, the movement of the actuation sleeve 105 manipulates a flapper member 125 which allows the valve 100 to move between an opened position and a closed position.

FIG. 1 shows the valve 100 in the opened position due to the flapper member 125 not obstructing a longitudinal central bore 170 through the valve 100. As shown, the actuation sleeve 105 is disposed concentrically within the housing 110. The actuation sleeve 105 represents a mechanism for moving the flapper member 125 to open the valve 100 although other types of actuators may be used in some embodiments. To move the valve 100 to the opened position, the actuation sleeve 105 slides within the housing 110 in the direction of direction arrow 60 based on fluid pressure from the control line 112. The flapper member 125 is selectively displaced due to movement of the actuation sleeve 105 across an interface between the flapper member 125 and a seat 205. To move the valve 100 to the closed position, the actuation sleeve 105 slides within the housing 110 in the direction of direction arrow 50. The movement of the actuation sleeve 105 out of contact with the flapper member 125 allows the flapper member 125 to obstruct the bore 170. The flapper member 125 is biased toward the seat 205 by a biasing member 130, such as a spring. The biasing of the flapper member 125 causes the flapper member 125 to move into contact with the seat 205 upon withdrawal of the actuation sleeve 105 and as a result, the valve 100 is in the closed position.

The valve 100 includes a first piston member 150 and a second piston member 175. The first piston member 150 is connected to the actuation sleeve 105 via a first piston rod 155, and the second piston member 175 is connected to the actuation sleeve 105 via a second piston rod 180. An end of each piston rod 155, 180 is connected to the actuation sleeve 105 at a hook area 115. The end of the first piston rod 155 is connected at the hook area 115 at a location that is offset from the connection location of the end of the second piston rod 180.

The first piston member 150 is movable within a chamber 160, the first piston member 150 having a first end and a second end. The fluid from the control line 112 enters into the chamber 160 at port 210. The fluid in the chamber 160 acts on the first end of the piston member 150, which results in a force in the direction of direction arrow 20 (FIG. 1A). The force is used to move the actuation sleeve 105 in the direction of direction arrow 60. In addition, fluid in the wellbore acts on the second end of the first piston member 150, which results in a force in the direction of direction arrow 30 (FIG. 1B). The forces applied to the first piston member 150 are communicated to the actuation sleeve 105 by the first piston rod 155.

The second piston member 175 is movable within a chamber 145, the second piston member 175 having a first end and a second end. The chamber 145 is in fluid communication with a cavity 135 via a port 140. The fluid in the cavity 135 acts on the first end of the piston member 175, which results in a force on the second piston member 175 in the direction of direction arrow 90 (FIG. 1B). In addition, fluid in the wellbore acts on the second end of the second piston member 175, which results in a force in the direction of direction arrow 80 (FIG. 1B). The forces applied to the second piston member 175 are communicated to the actuation sleeve 105 by the second piston rod 180. The cavity 135 may be filled with a gas and/or a compressible fluid. The cavity 135 may be charged such that the gas and/or fluid in the cavity 135 acts on the first end of the piston member 175 and results in a predetermined force. In one embodiment, the cavity 135 can be at an assembled atmospheric pressure. In another embodiment, the cavity 135 can be substantially free of gas as in a near vacuum. In another embodiment, the cavity 135 can be charged with a compressible fluid up to several hundred psi. In this manner, the cavity 135 acts as a fluid compensator for piston travel during functioning of the valve 100.

As shown in FIG. 1B, fluid in the wellbore acts on the first piston member 150 which results in a force in the direction of direction arrow 30, and the same fluid in the wellbore acts on the second piston member 175, which results in a force in the direction of direction arrow 80. The force applied to the first piston member 150 due to wellbore pressure is equal and opposite the force applied to the second piston member 175 due to wellbore pressure. In other words, the fluid pressure in the wellbore does not affect the movement of the actuation sleeve 105 because the force on the piston member 150 counteracts the force on the piston member 175. The use of the second piston member 175 allows the valve 100 to be a non-well sensing valve, which means that the functionality of the valve 100 is not affected by the fluid pressure in the wellbore.

As shown in FIG. 1, the valve 100 includes a biasing member 120, such as a spring, that is configured to bias the actuation sleeve 105 in the direction indicated by direction arrow 50. The biasing member 120 is attached to the actuation sleeve 105. The biasing member 120 is configured to be compressed when the actuation sleeve 105 is in an extended position (FIG. 1), and the biasing member 120 is configured to be uncompressed when the sleeve 105 is in a retracted position. The actuation sleeve 105 moves in the housing 110 to the extended position when the force applied to the actuation sleeve 105 due to fluid pressure from the control line 112 (via the first piston member 150) is greater than the force applied to the actuation sleeve 105 by the biasing member 120. The actuation sleeve 105 moves in the housing 110 to the retracted position when the force applied to the actuation sleeve 105 due to fluid pressure from the control line 112 (via the first piston member 150) is less than the force applied to the actuation sleeve 105 by the biasing member 120.

The biasing member 120 is designed and selected to overcome hydrostatic pressure of the fluid in the control line 112. As known in the art, hydrostatic pressure is a pressure exerted by a fluid at equilibrium due to the force of gravity. The control line 112 extends from the surface to the valve 100. Thus, when the valve 100 is positioned deep within the wellbore (>6000 feet) the control line 112 is long. As such, the hydrostatic pressure of the fluid in the long control line 112 that acts on the first piston member 150 may result in a large force being applied to the actuation sleeve 105. The biasing member 120 is designed to generate a force on the actuation sleeve 105 in the direction of direction arrow 50 that is greater than the force applied to the actuation sleeve 105 in the direction of direction arrow 60 as a result of the hydrostatic pressure of the fluid in the control line 112. In one embodiment, more force is required to move the actuation sleeve 105 to the retracted position as compared to the force required to move the actuation sleeve 105 to the extended position due to the hydrostatic pressure of the fluid in the control line 112. Additionally, since the valve 100 is a non-well sensing valve, as set forth herein, the design and selection of the biasing member 120 does not need to take into account the forces applied to the actuation sleeve 105 due to wellbore fluid pressure acting on the piston members 150, 175.

In one embodiment, a valve for use in a wellbore is provided. The valve includes a housing having a bore. The valve further includes an actuator sleeve movable within the housing between a retracted position and an extended position. The actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing. Additionally, the valve includes a first piston member attached to a first side of the actuator sleeve and a second piston member attached to a second side of the actuator sleeve, wherein wellbore fluid pressure acts on the first piston member, which results in a first force, and acts on the second piston, which results in a second force, and the first force and the second force are applied to the actuator sleeve in an opposite direction.

In one or more embodiments, the first piston member is in fluid communication with a control line.

In one or more embodiments, the fluid from the control line acts on a first end of the first piston member, and the wellbore fluid pressure acts on a second end of the first piston member.

In one or more embodiments, the second piston member is in fluid communication with a cavity in the housing.

In one or more embodiments, the fluid from the cavity acts on a first end of the second piston member, and the wellbore fluid pressure acts on a second end of the second piston member.

In one or more embodiments, a spring is attached to the actuator sleeve, the spring being configured to bias the actuator sleeve in the retracted position.

In one or more embodiments, the spring is configured to apply a force on the actuator sleeve that is greater than a force that results from hydrostatic pressure acting on the first piston member.

In another aspect, a valve for use in a wellbore is provided. The valve includes a housing having a bore. The valve further includes an actuator sleeve movable within the housing between a retracted position and an extended position. The actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing. The valve also includes a first piston member attached to a first side of the actuator sleeve. The first piston member is in fluid communication with a control line. The valve also includes a second piston member attached to a second side of the actuator sleeve. The second piston member is in fluid communication with a cavity in the housing. Additionally, the valve includes a biasing member configured to bias the actuator sleeve in the retracted position.

In one or more embodiments, the actuator sleeve is movable from the retracted position to the extended position in response to fluid pressure acting on the first piston member.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A valve for use in a wellbore, the valve comprising: a housing having a bore;an actuator sleeve movable within the housing between a retracted position and an extended position, wherein the actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing; anda first piston member attached to a first side of the actuator sleeve and a second piston member attached to a second side of the actuator sleeve, wherein wellbore fluid pressure acts on the first piston member, which results in a first force, and acts on the second piston, which results in a second force, and wherein the first force and the second force are applied to the actuator sleeve in opposite directions.

2. The valve of claim 1, wherein the first piston member is in fluid communication with a control line.

3. The valve of claim 2, wherein the fluid from the control line acts on a first end of the first piston member and the wellbore fluid pressure acts on a second end of the first piston member.

4. The valve of claim 1, wherein the second piston member is in fluid communication with a cavity in the housing.

5. The valve of claim 4, wherein the fluid in the cavity acts on a first end of the second piston member and the wellbore fluid pressure acts on a second end of the second piston member.

6. The valve of claim 1, further comprising a spring attached to the actuator sleeve, the spring being configured to bias the actuator sleeve in the retracted position.

7. The valve of claim 6, wherein the spring is configured to apply a force on the actuator sleeve that is greater than a force that results from hydrostatic pressure acting on the first piston member.

8. A valve for use in a wellbore, the valve comprising: a housing having a bore;an actuator sleeve movable within the housing between a retracted position and an extended position, wherein the actuator sleeve in the retracted position allows a flapper member to obstruct the bore in the housing;a first piston member attached to a first side of the actuator sleeve, the first piston member being in fluid communication with a control line;a second piston member attached to a second side of the actuator sleeve, the second piston member being in fluid communication with a cavity in the housing; anda biasing member configured to bias the actuator sleeve in the retracted position.

9. The valve of claim 8, wherein the actuator sleeve is movable from the retracted position to the extended position in response to fluid pressure acting on the first piston member.

10. The valve of claim 8, wherein the biasing member is configured to apply a force on the actuator sleeve that is greater than a force that results from hydrostatic pressure acting on the first piston member.