US2931384A

US2931384A - Safety valve for subsurface conduit strings

Info

Publication number: US2931384A
Authority: US
Inventors: Jr Earnest H Clark
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1956-02-13
Filing date: 1956-02-13
Publication date: 1960-04-05
Anticipated expiration: 1977-04-05

Description

April 5, 1960' E. H. CLARK, JR

SAFETY VALVE FOR SUBSURFACE CONDUI'I STRINGS Filed Feb. 13, 1956 .EZfi/Vffffl 62 A066, Je.

INVENTOR.

BY m M )v Ww/ flrraewa s:

Califl, assignor to Baker Earnest H. (liar-k, lira, Downe Califi, a corporation of Oil T oois, inn, Los Angeles, California Application February 13, 1956, Serial No. 564,952 7 Claims. (Cl. 137-498) The present invention relates to valve devices, and more particularly to valve devices for controlling flow of fluids in well bores.

An object of the present invention is to provide an improved valve device for automatically shutting off the flow oi fluids in a well bore when the rate of flow becomes excessive.

Another object of the invention is to provide a valve device for automatically shutting off the flow of fluids in a well bore when the rate of flow becomes excessive, in which a straight flow path for the fluid is present in the valve device when in open condition, thereby minimizing erosive wear on the parts by the flowing fluid.

A further object of the invention is to provide a valve device that closes automatically when fluid flow in the well bore becomes excessive, the valve device being adapted for incorporation in a tubular string disposed in the well bore and being capable of transmitting torque, in order that the tubular string can be operated to efiect its connection or dsconnection to and from another apparatus in a well bore, such as a well packer.

An additional object of the invention is to provide a simple and relatively inexpensive valve apparatus capable of being disposed in a well bore for the purpose of controlling flow of fluids therein.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. Such form is shown in the drawings accompanying and forming part of the present specification. This form will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure l is a longitudinal section through an embodiment of the invention, with the valve device disposed within a well casing and being in open condition;

Fig. 2 is a view similar to Fig. 1, with the valve device in closed position;

Fig. 3 is a cross-section taken along the line 3--3 on Fig. 1;

Fig. 4 is a cross-section taken along the line 4-4 on Fig. l.

The valve device A illustarted in Figs. 1 to 4, inclusive, of the drawings is adapted to be incorporated in a string of production tubing B disposed in a well casing C, the production tubing extending to the top of the well bore. The lower portion of the valve device may be connected to lower production tubing D, that can be secured to a lower well packer (not shown) anchored in packed-E condition in the well casing.

The valve device A includes an outer housing structure 19 consisting of an upper head 11 threadedly secured to the lower end of the string of production tubing B extending to the top of the hole. This head is threadedly attached to an upper housing section 12, which is, in

States Patent 0 turn, threadedly secured to an intermediate housing portion or coupling 13 threaded into a lower housing section or cylinder 14. This lower housing section is threadedly attached to a tubular sub 15, which may be threaded onto a lower section of tubing D forming part of a lower tubular string extending and connected to a lower well packer (not shown).

Integral with and depending from the housing head 11 is an inner tubular housing portion 16 having an annular valve seat 17 provided by its lower end. This valve seat is adapted to be engaged by a flapper valve head 18, to prevent upward flow of fluid through the valve apparatus and into the production tubing B thereabove. This flapper valve head is pivotally mounted on a hinge pin 19 secured to a leg 29 suitably welded, or otherwise attached, to the inner housing member 16.

The ability of the valve head 18 to swing upwardly into engagement with its companion seat 17 is dependent upon the position of a valve actuating sleeve 21, which is adapted to cam and hold the valve head 18 completely to one side of the passage 22 through the inner housing member, or which can permit the valve head to swing upwardly into engagement with its seat 17. This valve sleeve 21 is severed, or substantially cut away, at one side to permit the valve head to assume a depending position, such as disclosed in Fig. 1. It has upper holding surfaces 23 adapted to engage the marginal portion of the valve head 18, to hold the latter completely to one side of the passage 22 through the inner housing portion, these holding surfaces merging into downwardly and inwardly tapering cam surfaces 24 which can cam the valve head 18 from a closed to an open position when the valve actuating sleeve 21 moves downwardly with respect to the head, as described hereinafter.

The upper portion 25 of the actuating sleeve has an internal diameter slightly greater than the external diameter of the inner housing portion 16, to enable the sleeve to slide over the latter. The upper portion 25 of the sleeve opens downwardly into an enlarged portion 26, which terminates in an upwardly directed holding shoulder 27 adapted to engage the back side 23 of the valve head 18 when the latter engages the valve seat 17, thereby limiting upward movement of the sleeve 21 within the housing 1!). Proper orientation between thecam and

holding surfaces

24, 23 of the sleeve 21 and valve head 18 is maintained by welding, or otherwise suitably securing, a key element 29, or the like, to the inner housing member 16 opposite the leg 29 on which the valve head is pivot-ally mounted, this key element being received within a longitudinally extending slot 30 in the valve sleeve that extends downwardly from its upper end almost to its lower portion 31. This lower portion bridges the slot 39 and integrates the two halves or main portions of the sleeve 21.

The position of the sleeve 21 upwardly of the housing 10, in which the valve head 18 is engaged with the seat 17, or downwardly of the housing, in which the valve head 18 is maintained in its fully open position with respect to the seat 17, depends upon the rate of fluid flow through a tubular mandrel 32 slidably mounted in the housing. The upper end of this mandrel 32 is connected to the lower portion of the valve actuating sleeve 21 through the agency of a two-piece coupling ring 33. This ring has an outside diameter substantially equal to the inside diameter of the upper housing section 12, and

is provided with a lower inwardly directed flange 34 received with a peripheral 36 received within a peripheral groove 37 in the valve actuating sleeve. It is evident that the coupling ring 33 secures the sleeve 21 and mandrel 32 together for joint longitudinal movement within the housing 10.

groove 35 in the tubular man-. drel, as well as with an upper inwardly directed flange nular cylinder space terminates at an inwardly directed.

flange 42 of the intermediate coupling or housing, which slidably engages the periphery 4d of the mandrel. Intercommunication is provided between the central passage 43 through the tubular mandrel 32 and the annular cylinder space 4-1 by means of a plurality of ports 44 extending through the mandrel wall.

The valve head 18 may have a rubber or rubber-like 0 ring 45, or corresponding seal ring, mounted in its forward sealing face 46 and adapted to engage the valve seat 17, to prevent leakage between the valve head and.

the seat when the valve is in closed position. The piston 38 may have a. rubber or rubber-like O ring 146, or corresponding seal ring, disposed in a piston ring groove 47, which makes slidable sealing engagement with the cylinder wall 39. Similarly, the internal coupling flange 42 may have an internal groove 48 therein containing a rubber or rubber-like 0 ring 49, or corresponding seal ring, adapted to slidably seal with the periphery 40 of the mandrel 32. The seal element 46 on the piston and the seal ring 49 in the flange 42 need not be used, proaes'aaei 7 1 7 i pressure, whereas the fluid in the mandrel passage 43' itself must have a greater velocity, since the mandrel passage area R is less than the area S through the housing therebelow, with a consequent reduction in pressure the mandrel 32. Inasmuch as the pressure in the mandret passage 43 has been lowered, the pressure in the annular cylinder space 41 between the mandrel and the cylinder wall 39 will also be lowered, producing a pressure differential across the piston 38 tending to move the piston, the tubular mandrel 32 and valve actuating sleeve 21 connected therewith in an upward direction within the housing 16. Such pressure dilferential, however, is resisted by the compression spring 50, which will pre vent any movement whatsoever until the pressure differential achieves a value sufiicient to overcome the force of the spring.

Normally, the valve apparatus is in the open position disclosed in Fig. 1, in which the rate of fluid flow through the apparatus is insuflicient to produce a pressure diflierential across the piston 38 to overcome the compressive force of the resisting spring 50. However,- should the flow of fluid be increased to a considerableextent, as, for example, by the breaking of the surface vided the piston 38 makes a close sliding fit with the cylv inder wall 39 and the flange 42 makes a fairly close sliding fit with the periphery 40 of the mandrel, inasmuch as the apparatus will operate properly despite the presence of some minor leakage around the piston 38 and between the inner flange 42 and the periphery 40 of the Y mandrel 32.

The mandrel 32 is urged in a downward direction within the housing It to carry the actuating sleeve 21 down with it, by a helical compression spring 50 disposed in the annular space 41 the lower end of the spring bearing against the piston'33 and the upper end of the spring against the lower end of the coupling 13. The extent of downward movement of the mandrel 32 and actuating sleeve 21 under the influence of the spring 50 is limited by engagement of the two-piece coupling ring 33 with the upper end of the intermediate housing member or coupling 13, which functions as a stop member.

When the mandrel 32 and actuating sleeve 21 are in their lowermost position within the housing 10, the holding cam surfaces 23 are in engagement with the valve head 18, to hold it completely to one side of the

passage

22, 43 through the valve apparatus. When the mandrel and actuating sleeve move upwardly, as hereinafter described, the extent of such upward movement is limited by engagement of the valve head 18 with the valve seat 17 and of the holding shoulder 27 of the valve sleeve with the back or rear side 28 of the valve head. In shifting upwardly, the valve sleeve 21 has a portion 51 which will engage the rear side 28 of the valve head 18 and swing it into the path of fluid flowing upwardly through the valve apparatus, the fluid carrying the valve head 18 upwardly to its fully closed position against its'companion seat 17 7 w It is to be noted that the passage 43 through the piston 38, tubular mandrel 32, and actuating sleeve 21 is unrestricted, and that such unrestricted passage can continue upwardly through the inner housing portion 16. Thus, when the valve is in the fully open position shown connections at the top of the well bore, the velocity of flow through the mandrel will be proportionately increased, proportionately decreasing the static pressure within the annular cylinder space 41 above the piston 38. The pressure difierential across the piston may thereby be increased to an extent sufficient to overcome the force of the spring 5%, the pressure then shifting the mandrel 32 and the actuating sleeve 21 upwardly, the actuating sleeve sliding over the inner housing portion 16 and causing its lower portion 51 to engage the back side 28 of the valve head 18 and shift it toward the valve seat 17, the fluid flowing through the apparatus then carrying the valve head upwardly into engagement with the valve seat 17, closing the latter against upward flow of fluid. The extent of upward movement of the valve in Fig. 1, fluid can flow in an unobstructed and unrestricted manner through the valve apparatus, which will minimize erosion wear of the fiuid or fluent material on the valve parts. The area R through the tubular man drel passage 43, however, is substantially less than the area .S of the cylinder 14 below the piston or mandrel head 38. Accordingly, the fluid in the cylinder 14 below the piston38 will have a certain velocity and a certain sleeve 21 will be limitedby engagement of its holding shoulder 27 with the rear 'face 28 of the flapper valve head. The flow through the apparatus A is shut off completely, which will also eliminate the pressuredifierential across the piston 38. Despite this fact, the spring 50, which is now in a highly compressive state, such as disclosed in Fig. 2, cannot shift the mandrel 32 and sleeve 21 back to their "initial position to open the flapper valve 18, since the relatively high pressure in the mandrel 32 and in the lower tubing string D, as comparedwith the pressure in the production tubing B above the valve apparatus, will hold the valve head 18 against its seat 17 and prevent the cam faces 24 from shifting the valve head from the seat.

Should it be desired to again place the valve apparatus A in an open condition, pressure'of the proper amount is imposed on the fluid in the production tubing B, this pressure acting on the seating face 46 of the valve head 18, shifting it downwardly from the seat 17, thereby equalizing the pressure above and below the valve head 18. This equalizing of pressure permits the spring 50 to shift the mandrel 32 and actuating sleeve 21 downwardly, the cam surfaces 24 of the actuating sleeve moving the valve head 18 completely to its open position, whereupon the holding surfaces 23 slide across the marginal portion of the sealing face 46 of the valve head to insure its retention in its fully open position out of the path of fluid flow through the valve apparatus. Upward flow of fluid through the valve apparatus A and productiontubing D,

B is again permitted to take place.

head adjacent to said seat; tubular means movable in said housing upstream of said seat and engageable with said head to determine its engagement with said seat; said tubular means having a longitudinal passage from which fluid can flow past said head and into said outlet passage when said head is disengaged from said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular means; said tubular means having piston means thereon slidable along said housing and subject to the pressure of fluid in said housing upstream of said tubular means; said tubular means having a port upstream of the outlet end of said longitudinal passage establishing communication between said longitudinal passage and the exterior of said tubular means downstream of said piston means to subject the downstream side of said piston means to the fluid pressure in said longitudinal passage.

2. In a control valve: a housing having an outlet passage therethrough surrounded by a valve seat; a valve head movable laterally in said housing into engagement with said seat to restrict flow of fluid in said passage and laterally from engagement with said seat to permit flow of fluid in said passage; means for disposing said valve head adjacent to said seat; tubular means movable in said housing upstream of said seat and engageable with said head to determine its engagement with said seat; said tubular means having a longitudinal passage from which fluid can flow past said head and into said outlet passage when said head is disengaged from said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular means; said tubular means having piston means thereon slidable along said housing and subject to the pressure of fluid in said housing upstream of said tubular means; said tubular means having a port upstream of the outlet end of said longitudinal passage establishing communication between said longitudinal passage and the exterior of said tubular means downstream of said piston means to subject the downstream side of said piston mean to the fluid pressure in said longitudinal passage; and spring means engaging said tubular means to urge said tubular means in a direction upstream of said housing.

3. In a control valve: a housing having an outlet passage therethrough surrounded by a valve seat; a valve head movable laterally in said housing into engagement with said seat to restrict flow of fluid in said passage and laterally from engagement with said seat to permit flow of fluid in said passage; means for disposing said valve head adjacent to said seat; a tubular member slidable longitudinally in said housing upstream of said seat and engageable with said head to determine engagement of said head with said seat; said tubular member having a longitudinal passage from which fluid can flow past said head and into said outlet passage when said head is disengaged from said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular member; a piston secured to said tubular member and slidable along said housing at said internal area; said tubular member having a portion of less external diameter than the external diameter of said piston and slidable along said housing downstream of said piston to provide a substantially confined annular space around said tubular member between said portion and housing; said tubular member having a port upstream of the outlet end of said longitudinal passage establishing communication between said longitudinal passage and said annular space.

4. In a control valve: a housing having an outlet passage therethrough surrounded by a valve seat; a valve head movable laterally in said housing into engagement with said seat to restrict flow of fluid in said passage and laterally from engagement with said seat to permit flow of fluid in said passage; means for disposing said valve head adjacent to said seat; a tubular member slidable longitudinally in said housing upstream of said seat and engageable with said head to determine engagement of said head with said seat; said tubular member having a longi tudinal passage from which fluid can flow past said head and into said outlet passage when said head is disengaged from said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular member; a piston secured to said tubular member and slidable along said housing at said internal area; said tubular member having a portion of less external diameter than the external diameter of said piston and slidable along said housing downstream of said piston to provide a substantially confined annular space around said tubular member between said portion and housing; said tubular member having a port upstream of the outlet end of said longitudinal passage establishing communication between said longitudinal passage and said annular space; and spring means in said annular space engaging said piston to urge said piston and tubular member in an upstream direction within said housing.

5. In a control valve: a housing having an outlet passage therethrough surrounded by a valve seat; a valve head adapted to engage said seat to restrict flow of fluid in said passage, tubular means movable in said housing upstream of said seat and operatively connected to said head to determine its engagement with said seat; said tubular means having a longitudinal passage from which fluid can flow past said head and into said outlet passage when said head is disengaged from said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular means; said tubular means having piston means thereon slidable along said housing and subject to the pressure of fluid in said housing upstream of said tubular means; said tubular means having a port upstream of the outlet end of said longitudinal passage establishing communication between said longitudinal passage and the exterior of said tubular means downstream of said piston means to subject the downstream side of said piston means to the fluid pressure in said longitudinal passage; said valve head being pivotally carried by said housing; said tubular means including an actuator engageable with said valve head to swing said head from said seat completely to one side of said outlet passage in response to movement of said tubular means in an upstream direction within said housing.

6. In a control valve: a housing having an outlet passage therethrough surrounded by a valve seat; a valve head adapted to engage said seat to restrict flow of fluid in said passage, tubular means movable in said housing upstream of said seat and operatively connected to said head to determine its engagement with said seat; said tubular means having a longitudinal passage from which fluid can flow past said head and into said outlet passage when said head is disengaged from said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular means; said tubular means having piston means thereon slidable along said housing and subject to the pressure of fluid in said housing upstream of said tubular means; said tubular means having a port upstream of the outlet end of said longitudinal passage establishing communication between said longitudinal passage and the exterior of said tubular means downstream of said piston means to subject the downstream side of said piston means to the fluid pressure in said longitudinal passage; said outlet passage and longitudinal passage being coaxial; said valve head being pivotally carried by said housing; said tubular means including an actuator engageable with said head, in re sponse to movement of said tubular means in an upstream direction, to swing said head from said seat to one side of said housing completely out of the path of fluid flow through said passages.

7. In a control valve: a housing having an outlet passage therethrough surrounded by a valve seat; a valve head adapted to engage said seat to restrict flow of fluid in said passage; a tubular member slidable longitudinally in said housing upstream of said seat and operatively connected, to saidhead to determine engagement of said head with said seat; said tubular member having a longitudinal passage from which fluid can flow past said head and into said outlet'passage when said head is disengaged irom said seat, the area of said longitudinal passage being less than the internal area of said housing upstream of said tubular member; a piston secured to said tubular member and slidable along said housing at said internal area; said tubular member having a portion of less external diameter than the external diameter of said piston and slidable along said housing downstream of said piston to provide a substantially confined annular space around said tubular member between said portion and housing; said tubular member having a port upstream of the out let end of said longitudinal passage establishing communication between said longitudinal passage and said annular space; said outlet passage and longitudinal passage being coaxialj'said valve head being pivotally carried by said housing; and an actuator Connected to said tubular member, said actuator being engageable with said head, in response to movement of said tubular member in an upstream direction, to swing said head from said seat to one side of said housing completely out of the path of fluid through said passages. 7

References Cited in the file of this patent v UNITED STATES PATENTS 2,138,719 Wright .NOV. 29, 1938 2,373,034 Laird Apr. 3, 1945 2,411,392 Saville 'Nov. 19, 1946 2,583,295 Greer Jan. 22, 1952 2,601,654 'Wright June 24, 1952