Pressure Actuated Safety Valve

Abstract

A pressure actuated and resettable safety valve for controlling the flow through a well conduit which closes in response to an increase in pressure in the well conduit. Resetting means for opening the valve include a releasable piston for reopening the valve and resetting the valve closing mechanism. The valve closing mechanism retracting the resetting mechanism for resetting the valve to its initial position for reuse.

Description

BACKGROUND OF THE INVENTION

Generally, it is old to provide a subsurface safety valve for controlling the flow through a well conduit in response to abnormal conditions such as might occur when the well over produces, blows wild or in the event of a failure of well equipment. Prior art subsurface safety valves have in the past been controlled in response to fluid flow through the well conduit, differential pressure across the valve, a decrease in tubing pressure, or by a control line extending to the well surface.

The present invention is directed to various improvements in a subsurface safety valve in which the closure is caused to occur by an increase in tubing pressure in the well conduit and in which the safety valve is actuated and reset by application of pressure of a value in excess of shut-in tubing pressure in the conduit above the safety valve without requiring external control lines to the well surface.

SUMMARY

The present invention is directed to a subsurface well safety valve which is actuated upon an increase in pressure in the well conduit to cause the valve to close.

Yet a further object of the present invention is the provision of a pressure actuated subsurface well valve which may be reset after closure by controlling the pressure in the well conduit above the valve for reopening the valve and retracting the setting mechanism for further use.

A still further object is the provision of a pressure actuated subsurface safety valve having movable means which is yieldably urged in a direction to keep the valve in a normally open position and having piston means connected to the movable means and exposed to the pressure in the conduit to allow the valve to close upon an increase in conduit pressure.

Still a further object of the present invention is a provision of resetting means including a second movable means positioned in alignment with the first movable means for engagement therewith and actuating a retractable piston where after the valve closes the pressure above the valve may be increased to force the second movable means to open the valve and reset the first movable means for allowing the valve to assume its initial open position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an elevational view, partly in cross section, illustrating the top portion of the safety valve of the present invention being secured in a well tubing by a well lock,

FIG. 1B is a continuation of FIG. 1A showing the remainder of the safety valve in a normally open position,

FIG. 2 is a fragmentary elevational view, partly in cross section, illustrating the safety valve of the present invention with the valve in the closed position, and

FIG. 3 is a fragmentary elevational view, partly in cross section, showing the safety valve of the present invention with the resetting mechanism actuated and opening the valve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present improvement in a subsurface well safety valve will be shown, for purposes of illustration only, as incorporated in a flapper type well safety valve, it will be understood that the present well conduit pressure actuated safety valve may be used to control other types of valves.

Referring now to the drawings, and particularly to FIGS. 1A and 1B, the safety valve of the present invention is generally indicated by the reference numeral 10 and is installed in a well conduit such as a tubing 12 by any suitable means such as a conventional well lock 14 having locking dogs 16 which engage a notch 18 in a landing nipple in the tubing 12 and having a seal 20 for blocking off flow through the conduit 12 except through the valve 10.

The valve 10 generally includes a valve body 22, a valve seat 24, and a valve element such as a flapper valve 26 pivotally secured by pivot 28 to the body 22 for controlling the flow of well fluid through a valve bore 30 and thus the well conduit 12.

First movable means such as a sliding tubular sleeve 32 is provided below the valve 26. The sleeve 32 includes an upper end 34, which when moved upwardly, holds the valve 26 in a normally open position. The sliding tube 32 is yieldably urged upwardly to hold the valve 26 normally open. Any suitable yieldable means such as a spring 36 and/or a pressurized chamber 38 acting on the back side of a piston 40 on the sleeve 32 may be used to urge the sleeve upwardly. The piston 40 is also exposed on its top side to the pressure of the well fluid in the bore 30 and the tubing 12 through a port 42. Thus, the pressure in the well tubing acts on the top side of the piston 40 in a direction to move the upper end 34 of the sliding sleeve 32 downwardly and out of contact with the valve 26. When the pressure in the conduit increases, either unexpectedly or by shutting in the well tubing 12 at the well surface when operating conditions deteriorate, the pressure on the top side of the piston 40 will overcome the upward force on the sleeve 32 of the spring 36 and/or the pressurized chamber 38 to move the top end 34 of the sleeve 32 downwardly away from and release the valve 26. The valve 26 will then close as fluid flow reaches the back side of the valve 26 and by action of a valve spring 44 and/or flow through a port 46 on the back side of the valve 26. The valve element 26 will then seat on the valve seat 24, as best seen in FIG. 2, blocking the flow through the bore 30 and the well tubing 12.

The resetting mechanism is generally indicated by the reference numeral 50 and includes a second movable means or reset tubular sleeve 52, a movable body 54 and a movable bore closure member such as flapper 56. Both the reset sleeve 52 and the body 54 are longitudinally movable relative to each other and between the reset tube 52 and the body 54 which may include a shoulder 58 on the reset tube 52 and a coacting shoulder 62 on the body 54, and a spring 60 therebetween. Spring 62 may be omitted, if desired, as the reset tube 52 may move longitudinally relative to the body 54 when allowed by gravity. As best seen in FIG. 1B, the reset sleeve 52 is in axial alignment with the sliding tube 34 and includes a lower end 63 which abuts the upper end 34 of the sliding sleeve 32. The abutting ends 34 and 63 provide a metal-to-metal contact between the sleeve 32 and the reset tube 52 which protects the valve seat 24 and the flapper element 26 from the fluid flow through the bore 30.

As best seen in FIG. 1B, the reset body 54 is normally held in an up position by detent means such as a garter spring 64 carried by the body 22 which engages a notch 66 in the body 54. And as noted in FIG. 1B, the sliding sleeve 32 in its normal up position engages the resetting sliding sleeve 52 and moves it upwardly overcoming spring 62. The top end 68 of the reset sleeve 52 engages the pivoting bore closure or flapper 56 and holds the flapper 56 in a retracted position out of the valve bore 30 when the reset sleeve 52 is moved upwardly.

However, as best seen in FIG. 2, when the pressure in the tubing 12 and bore 30 increases to move the sliding sleeve 32 downwardly and close the valve 26, the reset sleeve 52 is allowed to move downward, either by gravity or by the action of spring 62, until sleeve shoulder 58 contacts body shoulder 60 thereby moving the upper end 68 of the reset sleeve 52 downwardly which in turn allows the bore closure member 56 to pivot about a pivoting support 70 to form a piston closing the bore 30. Thus, as best seen in FIG. 2, the safety valve 10 is in a closed position and is also ready to be reset when desired.

When resetting is desired, the pressure in the well tubing 12 above the valve 10 is increased and applied to the now closed bore closure member 56 to move the body 54 downwardly overcoming the spring 62. Downward movement of the body 54, as best seen in FIG. 3, carries the reset sleeve 52 downwardly pushing it against the flapper valve 26 to open the flapper 26 and hold the flapper 26 open so long as the sleeve 52 is held in the downward or extended position. The body 54 is moved downwardly until the garter spring 64 engages a second notch 70 thereby holding the body 54 in a downward position with the reset sleeve 52 holding the flapper 26 open even after pressure is relieved above the safety valve 10.

After the safety valve 10 has been reopened, as shown in FIG. 3, flow can then again commence through the tubing 12 and the bore 30 of the safety valve 10. Upward flow through the valve 10 will open the bore closure flapper 26 and flow through the tubing 12 but the downward position of the reset mechanism 50 remains as shown in FIG. 3 by the spring 64 engaging notch 70. Flow through the tubing 12 and valve 10 will allow the pressure therein to decrease whereby the force acting on the top side of the piston 40 decreases allowing the spring 36 and/or pressure in the chamber 38 to move the piston 40 and the sliding sleeve 32 upwardly. Upper movement of the sliding sleeve 32 will again carry the upper end 34 of the sleeve 32 into position to engage the flapper 26. The upper end 34 of sleeve 32 will also engage the lower end 62 of the reset sleeve 52 and will move the sleeve 52 upwardly and carry the movable body 54 upwardly to its original position, as best seen in FIG. 1B. Also, the top end 68 of the sleeve 52 will again engage the bore closure flapper 56 to hold the flapper 56 in the retracted position.

It is to be noted that the bore closure member 56 may be a frangible member, if desired, so that the member 56 may be ruptured, if desired, by pumping mud down the tubing 12 for killing the well if necessary.

Thus, in use, the subsurface well safety valve of the present invention will normally remain open and allow well fluids to be produced through the tubing 12 but will automatically close upon a predetermined increase in pressure in the tubing 12, but can be easily and simply reset when desired.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention is given for the purpose of disclosure, numerous changes in the details of construction and arrangement of parts will readily suggest themselves to those skilled in the art and which are encompassed within the spirit of the invention and the scope of the appended claims.

Claims

What is claimed is:

1. A pressure actuated subsurface safety valve for controlling the flow through a well conduit comprising,

a valve having a valve element and a valve seat and positioned in the bore of the conduit,

a first sliding sleeve positioned below said valve for controlling the actuation of the valve seat,

yieldable urging means acting on the first sleeve biasing the sleeve upwardly for holding the valve element in the open position,

piston means connected to the first sleeve and exposed to the pressure in the conduit bore below the valve for moving the sleeve downwardly upon increase in the bore pressure for causing the valve element to close,

a resetting second sliding sleeve positioned above the valve for opening the valve after the valve has closed by actuation of the first sleeve,

second piston means connected to the second sleeve and exposed to pressure in the conduit above the valve, said second sleeve positioned for engaging the valve element and opening the valve by conduit pressure above the valve, and

said first and second sleeves being longitudinally aligned for engagement with each other when the valve element is opened.

2. A pressure actuated subsurface safety valve for controlling the flow through a well conduit comprising,

a valve having a valve body and bore therethrough,

a first sliding sleeve positioned below said valve, the upper end of which when extended into the valve holds the valve in the open position and when the upper end is retracted away from the valve allows the valve to close,

yieldable urging means acting on the first sleeve in a direction to urge the first sleeve upwardly,

piston means connected to the first sleeve and exposed to the pressure in the conduit in a direction to move the sleeve away from the valve,

resetting means for opening the valve positioned above the valve having a second sliding sleeve and a movable body with a lost motion connection between the second sliding sleeve and movable body, said first and second sleeves being positioned for engagement with each other,

movable bore closure means connected to the movable body, said bore closure means being held out of the bore by the second sliding sleeve when the first sliding sleeve is in the extended position and holds the second sliding sleeve retracted, but said closure means allowed to close the bore when the first sleeve moves to a retracted position allowing the second sleeve to move and release the closure means thereby allowing the valve to be reset by increasing pressure in the bore above the closure means.

3. The apparatus of claim 2 including, detent means between the movable body and the valve body for releasably holding the movable body in a retracted and an extended position until moved by the second sliding sleeve.

4. A pressure actuated resettable subsurface safety valve for controlling the flow through a well conduit comprising,

a valve having a valve body and a bore,

a first sliding tubular sleeve positioned below said valve, the upper end of which when extended into the valve holds the valve in the open position and when the upper end is retracted away from the valve allows the valve to close,

yieldable urging means acting on the first sleeve in a direction to urge the first sleeve extended upwardly,

piston means connected to the first sleeve and exposed to the pressure in the conduit in a direction to retract the first sleeve downwardly,

resetting means positioned above the valve for opening the valve and having a second sliding tubular sleeve and a movable body with a lost motion connection between the second sleeve and the movable body,

said first and second sleeve being axially aligned for engagement with each other,

movable bore closure means connected to the movable body and movable into and out of the bore, said closure means being held out of the bore by the second sliding sleeve when the first sliding sleeve is in the extended position and holds the second sliding sleeve retracted, said closure means allowed to close the bore to form a piston therein when the first sleeve moves to a retracted position allowing the second sleeve to move and release the closure means whereby the valve may be reset by increasing pressure in the bore above the closed closure means.

5. The apparatus of claim 4 including, detent means between the movable body and the valve body for releasably holding the movable body in a retracted and an extended position.

6. The apparatus of claim 4 including,

spring means between the second tubular sleeve and the movable body.

7. The apparatus of claim 4 wherein the first and second sleeves are in engagement with each other when the valve is open and conduct flowing well fluid through the valve for isolating the well fluid from other valve components.