US3411584A

US3411584A - Well tools

Info

Publication number: US3411584A
Application number: US606707A
Authority: US
Inventors: Phillip S Sizer; John V Fredd; Turner G Garwood
Original assignee: Otis Engineering Corp
Current assignee: Otis Engineering Corp
Priority date: 1967-01-03
Filing date: 1967-01-03
Publication date: 1968-11-19
Anticipated expiration: 1985-11-19

Description

Nov. 19, 1968 Filed Jan. :5, 1967 42 lfl 205 195; 62 204 84 195 a]? 54 F g P. S. SIZER ET AL WELL TOOLS INVENTORS John V. Fredd Turner 6. Gdrwobd Phillip S. Sizer BY W ms Nov. 19, 1968 WELL TOOLS Filed Jan. 5, 1967 6 Sheets-Sheet 2 s R s a I .d W a; n34? 4 8 km? W 32 3/ 3 M 4 w o 3 K 3 I. r w w k\ \\\\K\X. m 3/ d 7/) m Fe. A F v G l D. H 1 H mm. O Y h. U 2 T u Y B 3. L. 5 1. D d 9 7 3 3 .I 94 nlUu vwu a M 3 3 333 4 4 u may F 3 Nov. 19, 1968 PQs. SIZER ETAL 3,411,534

WELL TOOLS Filed Jan. 5, 1967 e Sheets--Sheet Fi g.

F j 7 INVENTORS -J oh n V. Fred d Tu e r G. Garwood i P hp Sizer J WW ATTORNEYS Nov. 19, 1968 P. s. SIZER ET AL 3,411,584

WELL TOOLS Filed Jan. 5, 1967 6 Sheets-Sheet 6 mvrzmoas 190 48.2 John v. Fredd Fig .12 Turner 6. Garwood Ehillip S. Sizer United States Patent 01 fice 3,411,584 Patented Nov. 19, 1968 3,411,584 WELL TOOLS Phillip S. Sizer, John V. Fredd, and Turner G. Garwood, Dallas, Tex., assignors to Otis Engineering Corporation, Dallas, Tex., a corporation of Delaware Continuation-impart of application Ser. No. 471,995, July 14, 1965. This application Jan. 3, 1967, Ser. No. 606,707

32 Claims. (Cl. 16672) ABSTRACT OF THE DISCLOSURE This application discloses subsurface safety valves for controlling fluid flow in a well conduit. The valves are biased toward open position by control fluid pressure supplied from the surface. Systems are shown for supplying control fluid through a central flow passage in .a tubing string, an annular flow passage in the string, and a separate small line supported along the tubing string.

This is a continuation-in-part of an application filed July 14, 1965, by John V. Fredd, Turner R. Garwood, and Phillip S. Sizer, Ser. No. 471,995.

This invention relates to Well tools and more particularly relates to subsurface safety valves for wells.

It is an object of the invention to provide a well tool.

It is another object of the invention to provide a tool for controlling fluid flow through a conductor within a well.

It is a particularly important object of the invention to provide a subsurface safety valve for use in a well.

It is another object of the invention to provide a remotely controlled fluid actuated subsurface safety valve for a well.

It is another object of the invention to provide a subsurface safety valve for a well which is biased toward open position by fluid pressure from surface means and toward closed position by well pressure.

It is another object of the invention to provide a subsurface safety valve for controlling fluid flow in a flow passage of a well bore including a valve element having first surface portions exposed to fluid pressure supplied from the surface for moving the valve to and holding it at an open position and second surface portion exposable to well pressure at the valve for moving the valve toward closed position.

It is a further object of the invention to provide a subsurface safety valve including a main valve element ring seal having protective covering means which prevents direct contact of the seal ring with flowing well fluids when the valve is at an open position while permitting the ring seal to engage a seat surface when the valve is at a closed position.

It is a further object of the invention to provide a subsurface safety valve for a flow conductor in a well which includes a valve member having a ring seal and a retractible protective sleeve cover assembly which permits the seal to engage a seat surface when the valve is in closed position and also covers the ring protecting it from erosive fluid flow when the valve is in open position.

It is another object of the invention to provide a subsurface safety valve for a well adapted to be moved to and held at an open position by fluid pressure communicated to the valve through flow means from the surface.

It is another object of the invention to provide the combination of a subsurface safety valve and a landing nipple wherein control fluid under pressure is directed to the valve through a flow line separate from and supported on a tubing string extending to the valve.

It is another object of the invention to provide the combination of a subsurface safety valve and a landing nipple wherein fluid undtr pressure for controlling the valve is directed to the valve through an annular flow passage between concentrically positioned tubing strings extending to the landing nipple.

It is still a further object of the invention to provide a subsurface safety valve in combination with a landing nipple wherein control fluid under pressure is directed downwardly to the valve in a central flow passage through an inner tubing string concentrically positioned within an outer tubing string defining an annular flow passage for production fluids to flow upwardly from the valve.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIGURE 1 and FIGURE 1A taken together constitute a longitudinal view partially in section and partially in elevation of a subsurface safety valve embodying the invention supported within a landing nipple to which control fluid is directed through a control line extending to the surface exterior of the tubing string connected with the landing nipple;

FIGURE 1B is a fragmentary view in section and elevation along the line 1B1B of FIGURE 1;

FIGURE 2 is an enlarged fragmentary view in section and elevation of an upper central portion of the valve illustrating principally the stem of the valve member with apparatus for holding the valve member against rotation as it moves longitudinally;

FIGURE 3 is an enlarged View in section along the line 33 of FIGURE 2;

FIGURE 4 is a fragmentary view in section along the line of 44 of FIGURE 2;

FIGURE 5 is a perspective view of the valve stem guide member;

FIGURE 6 is a fragmentary view in perspective of the stem and an upper portion of the piston section of the valve member;

FIGURE 7 is an enlarged view in section and elevation along the line of 7-7 of FIGURE 1A;

FIGURE 8 is an enlarged fragmentary View in section and elevation of a lower portion of the valve illustrating the valve member at its closed position;

FIGURE 9 is an enlarged fragmentary view in section and elevation similar to FIGURE 8 illustrating the valve member at an intermediate stage during the opening of the valveshowing the ring seal of the valve member telescoped into its protective sleeve to prevent contact with flowing well fluids;

FIGURES 10 and 10A taken together constitute a view partially in section and elevation of the subsurface valve 3 of FIGURES l and 1A positioned in an alternate form of landing nipple for conducting control fluid through an annular flow passage around a central production fluid flow passage;

FIGURES l1 and 11A taken together constitute a view partially in section and partially in elevation of a modified form of the subsurface safety valve of FIGURES 1 and 1A in another form of a landing nipple for communi eating control fluid to the valve through a central flow passage with well production through an annular flow passage;

FIGURE 12 is a longitudinal view in section and elevation of an alternate form of subsurface safety valve in a landing nipple of the type illustrated in FIGURES l and 1A;

FIGURE 13 is an exploded view in perspective of the principal components of the locking assembly of the valve of FIGURE 12; and

FIGURE 14 is an enlarged fragmentary view in section of the encircled portion of FIGURE 12 denoted by the reference numeral 14.

Referring to the drawings, particularly FIGURES 1 through 7 of the drawings, a subsurface safety valve embodying the invention is releasably supported in a landing nipple 21 connected in a tubing string 22 extending to the surface. Control fluid from a surface control system, not shown, is supplied through a flow line 23 extending exterior of the tubing string to the safety valve for moving the safety valve to and holding it at an open position. So long as the fluid pressure applied through the line 23 exceeds a predetermined value, the safety valve is held at an open position permitting well fluids to flow upwardly to the surface through the tubing string 22. When the fluid pressure in the line 23 is reduced below such predetermined value, either by the surface control system or due to a leak in the line, the well pressure moves the safety valve to a closed position to prevent further flow through the tubing string to the surface. When the safety valve is used in offshore operations, such damage may be caused by a ship or barge striking the surface equipment on a supporting platform. After such closure, the safety valve is returnable to an open position by an increase of control fluid pressure transmitted to the valve through the line 23.

The subsurface safety valve 20 includes a tubular mandrel 24 supporting a valve member 25 which is longitudially slidable between upper closed and lower open positions. The safety valve is releasably locked in the landing nipple 21 by a locking assembly secured on a reduced upper end portion of the" mandrel. An external annular packing assembly 31 having upper and lower portions 31a and 31b is supported on the mandrel below the locking assembly for sealing around the safety valve within the landing nipple.

The assembly 30 is a well known type locking unit of the form illustrated in the United States Patent No. 2,798,559 issued to John V. Fredd, July 9, 1957, and is substantially similar to a locking device illustrated in US. Patent No. 2,920,704, issued to John V. Fredd, Ian. 12, 1960. The locking assembly includes expandable locking dogs 32 having external bosses 33 which are receivable in an internal annular recess 34 in the landing nipple for holding the safety valve against upward movement in the nipple. The locking assembly also includes a locking dog retainer sleeve 35 which is threaded along its lower end portion on the mandrel 24 and has a pair of oppositely positioned windows through which the locking dog bosses 33 project when the dogs are expanded as illustrated in FIGURE 1. The dog retainer is held against rotation on the mandrel to prevent accidental disengagement by a plurality of set screws 36 circumferentially spaced around the retainer and engaging the mandrel at their inward end surface. A locking dog expander sleeve 41 is telescopically slidably engaged over an upper end portion of the mandrel 24 with a lower end portion of the expander sleeve extending into the dog retainer sleeve 35 for actuating the locking dogs. The expander sleeve has an upper end external annular flange 42 for engagement of suitable running and pulling tools, not shown, for installing and removing the safety valve. As seen in FIGURE 18, a shear type pin 43 extends through a hole 44 in the dog retainer into a blind recess 45 opening outwardly in the expander sleeve 41 releasably locking the expander sleeve against movement relative to the mandrel to prevent accidental release of the locking assembly from the landing nipple.

Neither the inward end portion of the pin 43 nor the recess 45 has sloping or chamfered side wall surfaces, so that the pin is not carnmed out of the recess when a longitudinal force is applied to the dog expander. Thus, the pin 43 releases the dog expander only by shearing when an upward force is applied to the expander. The shear pin 43 is biased inwardly by an external annular ring Shaped spring wire disposed in an external annular recess 51 around the dog retainer 35. As the dog expander is moved relative to the mandrel and the dog retainer the inward end surface of the shear pin slides along the external surface of the expander sleeve until the hole 44 in the dog retainer and the blind recess 45 in the expander sleeve are aligned. The dogs are expanded outwardly into locking position and the spring 50 forces the shear pin inwardly into the recess in the expander sleeve thereby locking the sleeve against longitudinal movement until the pin is sheared.

Referring to the Patent No. 2,798,559, its expander sleeve 57, dog holder 49 and dogs 45 correspond, respectively, to the expander sleeve 41, dog retainer 35, and dogs 33 of the present invention. As indicated in the patent downward movement of the expander sleeve pivots the dogs outwardly and locks them at the expanded position of FIGURE 1 to hold the safety valve in the landing nipple. A running tool suitable for manipulating the locking assembly is illustrated in FIGURE 6 of the patent.

The packing assembly 31 is held on the mandrel between the lower end surface of the dog retainer 35 and an upwardly facing external annular shoulder 53 provided on the mandrel. The packing assembly includes a central spacer ring 54 provided, as best illustrated in FIGURE 2, with an external annular recess 55 and an internal annular recess which are interconnected by a lateral port 61. The internal recess 60 of the ring 54 provides an annular flow pasage around the mandrel within the ring, FIGURES 3 and 4. The ring 54 is aligned longitudinally with an internal annular recess 62, FIGURE 1, within the landing nipple which communicates with a port 63 through the landing nipple to admit control fluid from the line 23.

The valve member 25 has an upper stem portion 63, see particularly FIGURE 6, slidably disposed in a bore portion 64 of the mandrel. The mandrel 24 has a laterally opening blind pocket 65 which extends horizontally into the mandrel intersecting its bore portion 64 to receive a U-shaped guide and stop member which limits the downward movement of the valve member 25 and prevents rotation of the valve member about its longitudinal axis. The slot 65 is generally rectangular in cross section as seen in a vertical plane, FIGURE 4. The guide member 70, FIGURE 5, has leg portions 71 which span a reduced portion 72 of the valve stem along opposing longitudinal recesses 73 defined by upper shoulders 74, lower downwardly divergent shoulder surfaces 75, and substantially flat parallel surfaces which are engageable by inside leg surfaces 81 of the guide member to hold the valve member against rotation. The subsurfaces 81 of the guide member are substantially parallel and spaced slightly farther apart than the valve member surfaces 86 so that the Valve member slides freely longitudinally while being held against rotation. The bight portion 83 of the guide member has a hole 83 between and aligned parallel with the legs 71 to receive a shear pin 84 extending through the guide member into the valve member in a hole 85 provided in the reduced portion 72 of the valve stem. The shear pin 84 locks the valve member at a partially open position during installation of the safety valve and is shearable, as discussed herein-after, to release the valve member so that it may move between its closed and open positions. As evident from FIGURE 2, the guide member 70 is held in its slot 65 by an inside curved surface portion of the spacer ring 54 which engages the outer curved surface 90 of the bight portion of the guide member. The mandrel 24 has a hole 91 positioned opposite and substantially aligned with the port 61 and with the shear pin hole 85 through the valve member stem when the valve member is positioned as illustrated in FIGURES 24. The hole 91 receives a suitable tool such as a punch for driving the fragment of the shear pin 84 from the valve stem and preparing the safety valve for reuse after removal from the landing nipple at the surface, as discussed hereinafter. The downwardly facing shoulders 74 on the valve member stem are engageable with the top faces of the legs 71 of the guide member 70 to limit downward movement of the valve member in the mandrel.

The valve member stem portion 63 has a blind upwardly opening bore 92 which communicates along its lower end portion with a lateral port 93 in the stem. The mandrel 24 has a lateral port 94, FIGURE 3, circumferentially spaced approximately 90 degrees from the port 61 and longitudinally spaced downwardly from the port 61 so that at its outer end the port 94 opens into a portion of the recess 60 within the spacer ring 54 while at its inward end a portion of the port 94 opens into the mandrel bore portion 64 below the guide member 70. Control fluid flows from the line 23 into the safety valve through the spacer ring port 61, within the spacer ring in the recess 60 to the mandrel port 94, and inwardly from the recess through mandrel port 94 in the mandrel bore portion 64. The control fluid flows within the bore portion 64 downwardly around the valve member stem along a slightly enlarged mandrel bore portion 64a through which the control fluid flows downwardly into a substantially enlarged mandrel bore portion 95. While the primary path for control fluid between the port 61 and the enlarged mandrel bore portion 95 is by way of the port 94 and along a valve member recess 73 communicating with the port 94, it will also be recognized that some control fluid finds its way into the mandrel bore portion 64, the valve member bore 92, and through the valve member port 93 opening into the bore 92. The guide member 70 fits loosely around the stem portion 72, while the stem portion fits somewhat loosely within the mandrel bore portion 64 to facilitate the reciprocation of the valve member stem within the mandrel bore portion 64 during movement of the valve member between its closed and its open positions. Further, in one modified form of the subsurface safety valve, as illustrated in FIGURE 11 and discussed hereinafter, the primary path for the control fluid is downwardly through the bore portion 64 of the mandrel and the valve stem bore 92 through the port 93 into the enlarged mandrel bore portion 95.

A plug 100 is threaded into a reduced bore portion 101 of the mandrel, thereby closing the mandrel bore preventing fluid flow upwardly through the bore from its portion 64 so that in the form of the subsurface safety valve illustrated in FIGURES 1 through A the flow control fluid is limited to that entering the valve through the port 61 while, as mentioned above and discussed in more detail hereinafter, the plug 100 is removable where the control fluid is directed downwardly through a central flow passage entering the upper end of the mandrel bore.

The mandrel 24, as shown particularly in FIGURES 1A, 8 and 9, is provided with a plurality of circumferentially spaced elongated, substantially oval shaped lateral outlet ports 102, each defined by a continuous edge surface in the mandrel, the upper and lower end portions of which slope upwardly for reducing turbulence in the fluids flowing through the valve and to more efficiently direct the existing fluids upwardly toward similarly spaced shaped and landing nipple ports 103. The mandrel has an external annular flange 104 aligned with the lower ends of the ports 102. The flange 104 has a downwardly convergent external shoulder surface 105 which engages an upwardly divergent internal annular shoulder surface formed at an angle substantially corresponding with the shoulder surface 105 providing a seat surface for limiting the downward movement of the safety valve in the landing nipple. A plurality of ring seals 111 are disposed in external annular recesses in a lower end portion 112 of the mandrel 24 longitudinally spaced below the shoulder 105 for sealing around the mandrel with an internal bore surface 113 of the landing nipple below its shoulder seat surface 110. The lower end of the mandrel 24 comprises a downwardly convergent outer surface 114 adjoining a downwardly divergent inner annular seat surface 115.

The valve member 25 is enlarged below its stem 63 providing a piston portion which is slidable in the mandrel bore portion 95 responsive to control fluid pressure from above and well pressure from below for mov ing the valve member between its closed and open positions. A ring seal 121 is disposed between spacer rings 122 within an external annular recess 123 in the piston portion for sealing around the piston portion within the mandrel. The external surfaces of the valve member above its ring seal 121 comprise first surfaces exposed to control fluid pressure biasing the valve member downwardly toward open position. The external surfaces of the valve member below the ring seal 121 comprise second surfaces exposed to well pressure biasing the valve members toward closed position. The piston portion is slightly reduced in outside diameter along upper and

lower portions

124 and 125, respectively, above and below the ring seal to facilitate longitudinal movement of the piston within the mandrel and minimize possible binding which would impair opening and closing of the valve. The mandrel bore portion 95 is slightly reduced in diameter over a major portion 95a of its length along which the ring seal 121 slides as the valve member moves between closed and open positions. A slightly enlarged portion of the mandrel bore portion 95 above its section 95a also tends to minimize binding of the piston portion of the valve member during reciprocation within the mandrel.

The valve member 25 has a central skirt portion 25a having a plurality of circumferentially spaced longitudinal slots or ports below the piston portion. The top and bottom ends of the ports are designed by inwardly convergent upper and lower end surfaces 130a. The ports 130 interconnect so that the only actual structure of the valve member extending along its port section comprises post members 131 forming the skirt portion and connecting a lower end closure means portion 132 of the valve member with its piston portion.

The valve member has an external annular recess 133 in which is disposed an O-ring 134 which seals between the valve member and the mandrel below the ports 102 when the valve member is at an upper closed position. The lower valve member end portion 132 is reduced in diameter along an intermediate portion 132a and further reduced in diameter along a lower externally threaded end portion 1321;. A protective sleeve 135 including an internal flange and an upwardly extending cylindrical skirt 141 is disposed around the lower end portion 132a of the valve member biased upwardly by a spring 142 confined between the protective sleeve and a retainer ring 143. The lower end of the spring engages the upper face of an internal annular flange 144 of the retainer ring, while the upper end of the spring is received in an internal annular recess 145 of the protective sleeve. The sleeve 135 telescopes upwardly with its skirt portion 141 extending over the ring seal 134 to protect the seal against damage by well fluids when the valve member is at a 7 lower open position as illustrated in FIGURE 1A. The sleeve has one or more pressure equalization or relief ports to facilitate fluid flow therepast and thus facilitate movement of the sleeve on the valve member as the valve opens and closes.

A nut 151 is threaded on the reduced lower end portion 132!) of the valve member and has an external annular flange 152, the upper surface 153 of which engages the lower end surface of the retainer ring 143 holding it on the valve member. A nose member 154 is threaded along an upper internally threaded intermediate portion 155 on the retainer ring 143. The nose member telescopes on the lower end portion of the valve member between an upper position, FIGURE 9, and a lower position, FIGURE 8. The nose member is retained on the valve member by engagement of the lower end surface of the nut 143 with the upper flange surface 153 on the nut 151 when the nose member and valve member are telescoped apart to the position of FIGURE 8. The nose member and valve member telescope together until a lower flange surface on the nut 152 engages an internal annular shoulder 161 within the nose member, FIGURE 9. The nose member has a graduated bore, including a lower portion 162, an intermediate portion 163, and an upper portion 164 which includes the internally threaded section 155. The bore portion 162 receives the body of the nut 151, while the bore portion 163 receives the flange portion of the nut. The bore portion 163 of the nose member is generally rectangular in cross section with somewhat rounded corners 163a while the nut flange 152 is similarly shaped with flat side surfaces whereby the nut 151 allows the nose member to slide longitudinally while holding it against rotation on the valve element. The bore portion 164 has a lower internal annular end flange surface 165 which engages the lower end of the nut 143 limiting the extent to which the nut is threaded into the bore portion of the nose member. The bore portion 154- of the nose member above its threaded section receives the protective sleeve 135 and a portion of the valve member which slides into the protective sleeve as the nose member and valve member telescope between the various positions illustrated during operation of the subsurface safety valve.

The nose member has an upper end upwardly convergent seat surface engageable with the similarly sloped seat surface 115 on the lower end of the tubular mandrel 24, FIGURES 8 and 9. The skirt portion 141 of the sleeve 135 similarly has an upper end edge surface 171 engageable with the mandrel seat surface 115, FIGURE 8, when the valve is closed and the ring 134 is telescoped out of the protective sleeve into the bore of the lower end portion 112 of the mandrel. The sleeve 135 provides a protective cover for the ring seal 134 to protect it from being flow out by well fluids when the valve is at its open position while the telescopic action between the nose and the protective sleeve permits the ring seal and the protective sleeve to move into protective relationship within the nose member prior to the separation of the seat surfaces on the nose member and the mandrel, so that the protective sleeve also is moved fully into the nose member and thus is not subjected to flowing well fluids until after the valve is fully open. The protective sleeve similarly is not subjected to a pressure differential during the opening procedure of the valve.

Referring to FIGURE 1, an outer sleeve is supported in concentric spaced relation on the landing nipple defining with the outer surface of the nipple an annular flow passage 131 for directing upwardly flowing well fluids from the lower landing nipple ports 103 past the safety valve. The landing nipple has upper circumferentially spaced elongated ports 182 for reentry of upwardly flowing well fluids from the annular passage 181 into the central bore of the landing nipple above the safety valve. The sleeve 180 is threaded along a lower end portion 183 on an enlarged portion 184 of the landing nipple, FIG- URE 1A, and suitably welded as at 185 at its lower end to a further enlarged portion of the landing nipple. A head member 191 is threaded into the upper end of the sleeve 180 and suitably secured as by welding at 192. The head member extends downwardly within the outer sleeve over an end portion of the landing nipple 24 to the upper ends of the upper landing nipple ports 182. The landing nipple is connected by an internally threaded coupling 193 to an upper portion 22a of the tubing string 22 extending to the surface. The lower end portion 190 of the landing nipple is threaded into a coupling 194 connected on a lower portion 22b of the tubing string.

A fitting 195, FIGURE 1, is secured through the outer sleeve 180 to the outer surface of the landing nipple 24 over its port 63 for directing control fluid from the control line 23 into the subsurface safety valve through the port 63. The fitting 195 is suitably secured as by a circular weld at 200 to a ring portion 201 which is similarly secured by welding .at 202 into a lateral aperture 202a in the outer sleeve 180. The ring 201 has cylindrical inner and outer surface portions 201a and 2011; which conform to the curvature of the inner and outer surface, respectively, of the sleeve 180 so that when the fitting 195 is secured through the sleeve smooth inside and outside surfaces are provided extending to the fitting. The fitting has a cylindrical inward end surface 195a engaging the outer wall surface of the landing nipple when the fitting is suitably secured as by welding at 203 to the outer surface of the landing nipple around the port 63. The fitting 195 has a lateral flow passage 204 communicating with a vertical flow passage 205 into which the lower end of the control line 23 is connected. Control fluid thus flows through the control line 23, the

flow passages

205 and 20 and into the landing nipple port 63.

The bore of the landing nipple is enlarged along a lower portion 210 within the portion 190 to provide space for the flow of well fluids around the nose member 154, of the safety valve upwardly into its valve member ports when the valve is at its lower open position as in FIGURE 1A.

The subsurface safety valve is installed at its down hole operating position by use of a suitable running tool of the type shown in FIGURE 6 of the Patent 2,798,559. The running tool R of the patent is assembled on the safety valve 20 with the dog expander 41 of the safety valve locked by the running tool at an upper position at which the locking dogs 33 are free to remain at their retracted positions. The running tool and safety valve are supported from a handling string of tubing, not shown, on which they are lowered into the tubing 22 until the shoulder surface 105 on the safety valve mandrel engages the landing nipple seat surface 110 supporting the safety valve against downward movement in the landing nipple. When the safety valve is seated in the landing nipple the running tool is manipulated as described in the reference patent to drive the dog expander 41 downwardly pivoting the locking dogs 32 outwardly until their outer bosses 23 enter into the locking recess 34 of the landing nipple. As the dog expander is driven downwardly the inward end surface of the locking pin 43 slides along the exterior surface of the dog expander. When the dog expander is at its lower end position, fully expanding the locking dogs, the pin 43 is aligned with the recess 45 in the dog expander. The spring 50 forces the locking pin inwardly with its inward end portion being received within the recess 45 holding the expander against upward movement at a position which holds the locking dogs expanded outwardly as illustrated in FIGURE 1.

The safety valve is inserted into and locked in its landing nipple in a partially open condition, FIGURE 1, to facilitate its movement to a fully seated position, FIGURE 1A, in a liquid filled hole. The valve member 25 is locked at such open position by the shear pin 84, FIGURES 1 and 2, which holds the valve member 25 at such a longitudinal position relative to the mandrel 24 that the lower end portion 132 of the valve member is spaced below the mandrel seat surface 115, FIGURE 1A, sufliciently that fluid readily flows upwardly around the nose 154 of the valve member into the valve member ports 130. Thus, as the valve is lowered into the landing nipple and the ring seals 111 enter the nipple bore portion 113, fluid is readily displaced or bypassed around the nose member of the valve into its ports without compressing the fluid and creating piston-like action which might hinder insertion of the safety valve into its landing nipple. At the partially open position at which the shear pin 84 locks the valve member, the nose member is biased downwardly on the valve member by the spring 142 to the maximum distance permitted by the retainer 143 whose lower end surface engages the top flange surface 153 of the nut 151. The ring seal protective sleeve 135 is held at its upper end position by the spring 142, so that the sleeve fully covers the ring seal 133 protecting it from well fluids.

After the safety valve is locked by its expanded dogs in the landing nipple, the running tool is disengaged from the locking assembly of the safety valve and withdrawn to the surface. Control fluid is then supplied from a surface unit, not shown, through the line 23 to the safety valve 20 for releasing the valve member by shearing the pin 84 and holding it at an open position. The control fluid flows downwardly in the line 23 and through the fitting 195 in its flow passages 205 and 204 into the port 63 of the landing nipple. The fluid then flows through the port 63 into the internal annular recess 62 of the landing nipple between the upper and lower portions of the annular packing 31. The control fluid flows in the annular recess 62 around the spacer ring 54 to the port 61 through which it flows into the internal annular recess 60 within the ring 54 around the mandrel 24 and guide member '70. The fluid flows within the passage 60 to the radial port 94 in the mandrel 24 and through the port inwardly into the bore 64 of the mandrel below the guide member 70. The control fluid then flows downwardly within the bore 64 along the stem portion 63 of the valve member into its enlarged bore portion 64a through which it flows into the further enlarged bore portion 95 of the mandrel. Due to the relatively loose fit of the stem portion of the valve member within the bore '64 some of the control fluid flows upwardly around the stem and downwardly through its bore 92 to the lower stem port 93 through which the fluid enters the mandrel bore 95.

The control fluid supplied through the line 23 from the surface applies a downward force to the valve member 25 resulting from the pressure of the control fluid imposed on upwardly facing first surface portions of the valve member above its ring seal 121 over an effective area defined within the line of sealing engagement of the ring seal 121 with the internal wall surface of the mandrel along its bore portion 95. Well pressure acts upwardly on the valve member surfaces below the ring seal 121 over an effective area also defined by the seal 121. When the downward force of the control fluid pressure on the valve member exceeds the combined force of the well pressure and the holding force of the shear pin 84, the pin is sheared releasing the valve member for longitudinal movement. The force of the control fluid pressure moves the valve member downwardly to its fully open position. The downward movement of the valve member is limited by the engagement of the shoulder surfaces 74 on the valve member stem with the top surfaces of the legs 71 of the guide member 70. Also the guide member prevents rotation of the valve member to maintain alignment of the ports 130 with the mandrel ports 102.

The pressure of the control fluid is adjusted to exceed the well fluid pres-sure to hold the valve member at its lower open position at which well fluids flow upwardly through the valve to the surface in the tubing string 22. So long as the control fluid pressure is maintained at a pressure exceeding the well pressure, the valve member is held at its lower open position. The control fluid pressure is acting downwardly on the valve member above the seal 121 while the well fluids are acting upwardly on the valve member below the seal 121 at a pressure slightly reduced by the pressure drop through the mandrel bore around the valve member.

The valve member is moved upwardly to its closed position by well pressure when such -well pressure is in excess of the control fluid pressure applied through the line 23. Such a relation between control fluid and well pressure may occur by a reduction in control fluid pressure effected either by a control led reduction by the surface control fluid system, not shown, or by rupture of the control fluid flow system, such as by breakage of the line 23 at or near the surface resulting from an impact from a ship or barge or other accidental occurrences. Basically the sub-surface safety valve functions to minimize loss of well fluids at the surface and thus the control fluid pressure system is adapted to respond to any damage which could cause such loss. In addition to the loss of expensive fluids, surface system ruptures may result in fires which can destroy an entire platform and perhaps other equipment such as ships and barges. The surface control fluid system may include various detectors, not shown, designed to respond to blows of sufficient magnitude or other physical occurrences which might be calculated to possibly cause a rupture of the well fluids flow system at the surface and thus permit closure of the subsurface safety valve in anticipation of such damage.

When the control fluid pressure is reduced, as discussed above, to a level at which the upward force of well pressure on the valve member 25 below its ring seal 121 exceeds the downward force of the control fluid on the upper valve member surfaces above the ring seal, the upward force lifts the valve member to its closed position illustrated in FIGURE 8. The relative positions of the nose member 154, the protective sleeve 135, and the valve member are illustrated in FIGURE 1A When the valve is at its full open position. It will be observed that at the open position of the valve the upper end surface 171 of the sleeve 135 is substantially above the upper end surface 170 of the nose member. As the valve member moves upwardly the upper end surface 171 of the sleeve 135 engages the lower end seat surface on the mandrel 24 preventing further upward movement of the protective sleeve while the valve member continues upwardly moving its ring seal 134 upwardly out of the protective sleeve after the protective sleeve engages the lower end of the mandrel. The ring seal moves into the bore 112a of the lower end portion of the mandrel 24. When the ring seal enters the bore 112a the well pressure acting on the valve member over an area defined by the line of sealing of the seal with the mandrel bore surface continues lifting the valve member as well pressure is transmitted around the sleeve 135 to the ring seal due to the loose fit of the sleeve in the nose member and around the valve portion 132. The valve member continues moving upwardly until the upper end surface of the nose member engages or seats against the seat surface 115 of the mandrel. The nut 151 which is fixed on the valve member supports and lifts the retainer 143 as the upper flange surface 153 of the nut engages the lower end surface of the retainer, FIGURES 1A and 8. The nose member is fixed to the retainer so that as the nut 151 lifts the retainer the nose member is simultaneously moved upwardly and, therefore, when the end surface on the nose member seats against the seat surface 115 of the mandrel the valve member 25 is held against any further upward movement by the retainer 143 and the nut 151.

As the valve member lifts the nose member to its upper seated position to close the valve the nose member telescopes upwardly over the protective sleeve 135 so that when the valve is fully closed, FIGURE 8, the upper end surfaces of both the protective sleeve and the nose member are engaged with the mandrel seat surface 115. The

1 1 nose member end surface 170 and the mandrel seat surface 115 are both sloped and provided with a finish which may effect a seal when the surfaces are engaged as in FIGURE 8 and 9.

From the time that the upwardly moving ring seal 134 enters the bore portion 112a of the mandrel substantially no flow occurs upwardly into the valve so that until the complete closure of the valve the mandrel and nose member seat surfaces are protected from flow cutting. The only flow into the lower end of the mandrel past the seat surface 115 is a very minor quantity necessary to displace the valve member upwardly from the position at which the ring seal 134 makes initial entry into the mandrel to the fully closed position of FIGURE 8. The valve member moves upwardly lifting the nose member 154 until the seat surface 170 on the nose member engages and is stopped by the seat surface 115 on the mandrel thereby stopping the upward movement of the valve member. So long as the control fluid pressure remains at a sufficiently low level the well pressure holds the valve member at its upper fully closed position. At the fully closed position of the valve generally there is minute leakage between the seat surfaces 170 and 115 so that well pressure acts on the valve element over an effective area defined by the line of sealing engagement of the ring seal 134 with the surface of the mandrel bore portion 112a.

The subsurface safety valve is reopened by increasing the pressure of the control fluid conducted to the valve through the line 23. Such reopening may occur after repair of surface damage, if any, other correction of conditions which effected closing of the valve, or if the valve was simply closed for other reasons by reestablishing the needed pressure. The control fluid pressure is increased to a value suflicient to apply a downward force to the valve member exceeding the upward force applied by the well pressure to the valve member. When the valve is closed the only pressure on the opposite sides of the ring seal 121 results from the pressure above the seal of the control fluid which may be only the hydrostatic pressure of the column of control fluid, while similarly the pressure below the seal is applied by the column of well fluids in the tubing string above the valve as transmitted through the

ports

103 and 102. Also, since with the seal 121 at its closed position the seal between the

seats

115 and 170 may leak slightly, the well pressure acts on the valve member below the seal 121 biasing the member upwardly. The increase in control fluid pressure applied to the first upper surfaces of the valve member above the ring seal 121 through the various flow passage routes previously described forces the Valve member downwardly relative to the valve mandrel, the protective sleeve 135, and the nose member 154. The well fluid pressure holds the nose member 154 against the mandrel seat surface 115 while the spring 142 supported on the retainer 143 biases the sleeve 135 against the mandrel seat surface as the lower end portion of the valve member is telescoped into the nose member. The enlarged valve member portion 132s supporting the ring seal 133 is telescoped downwardly into the protective sleeve until the lower end shoulder surface 132d on the valve member engages the top surface of the sleeve flange 140 moving the protective sleeve downwardly from the seat surface 115 into the nose member until the lower flange surface 160 on the nut 151 engages the internal shoulder surface 161 within the nose member, FIGURE 9.

As the valve member moves downwardly into the sleeve and nose member its movement is opposed by the force of well pressure acting over the area defined by the ring seal 134 only until the ring seal moves out of the bore portion 112a into the sleeve 141. As the ring seal moves across the minute gap between the sleeve 141 and the lower end of the mandrel the primary seal of the valve is etfectively transferred from the ring seal 134 to the engaging seat surfaces 170 on the nose member and 115 on the mandrel with well pressure holding the nose member against the mandrel as the O-ring is moved by the valve member downwardly into the protective sleeve and the protective sleeve is moved into the nose member. The nose member is held against the mandrel by a force determined by the well pressure acting over an effective area defined within the line of sealing engagement of the seat surfaces and 170. Thus, after the ring seal 134 is fully telescoped into the protective sleeve and the protective sleeve into the nose member, the control fluid above the ring seal 121 must exert sufficient downward force to displace the nose member from the lower end of the mandrel against the force applied by the well pressure on the nose member acting over the area defined by the engaged

seat surfaces

115 and 170, as just discussed.

If the safety valve is operating within well fluids which are substantially all gas and thus the various chamber spaces within the nose member around the lower end portion of the valve member are gas filled, the downward movement of the valve member into the nose member will generally compress the gas while the nose member is held on seat, though pressure conditions may momentarily develop which will displace the nose member slightly downwardly momentarily thus permitting pressure equalization around the nose member as the valve member moves downwardly. Once the ring seal 134 enters the protective sleeve 141 any pressure increase within the nose member due to the downward movement of the valve member is relieved upwardly around the sleeve 141 between the sleeve and the inside surface of the upper end skirt of the nose member. If the safety valve is function ing in an environment which causes the nose member to be filled with liquid around the portions of the valve member received within the nose member, the downward movement of the valve member between its upper end position and its entry into the protective sleeve 141 will clearly momentarily displace the nose member from the mandrel to permit escape of incompressible liquid from the nose member between the seat surfaces 170 and 115. As in the case of the nose member being filled with gas, once the ring seal 134 passes into the protective sleeve any further compressed liquid within the nose member may be displaced upwardly around the protective sleeve within the nose member back into the bore of the mandrel.

Further downward movement of the valve member forces the nose member downwardly moving its upper end surface 170 downwardly away from the mandrel seat surface 115 opening the valve to upward flow of well fluids through the valve to the surface, as previously described. As the valve member moves downwardly be tween the positions of FIGURES 8 and 9, the engagement between the nose member surface 17 0 and the mandrel seat surface 115 aid in protecting the ring seal from the well fluids so that the ring seal is fully telescoped into the protective sleeve and the sleeve is moved downwardly away from the seat surface of the mandrel without exposing either the ring seal or the protective sleeve directly to the effects of the full pressure and flow of well fluids. It is particularly advantageous for the ring seal to be moved across the gap between the lower end of the mandrel and the protective sleeve with reduced pressure differential being imposed across the joint between the sleeve and mandrel thereby minimizing a possibility of damage to the ring seal while it is being moved from the bore of the valve mandrel into the sleeve.Thus, the seal between the nose member surface and the mandrel seat surface 115 is fully broken to permit well fluids to flow through the valve only after the valve member is moved downwardly sufficiently to protect the ring seal within the sleeve 135 and the sleeve has been displaced downwardly from the mandrel into the nose member.

As soon as the seal is broken between the nose member and the valve member the fluid pressure differential across the nose member is equalized so that well pressure acts on both the upwardly and downwardly facing nose member surface portions so that the nose member is no longer biased upwardly by well pressure. The spring 142 expands forcing the nose member downwardly on the valve member until the lower end surface of the retainer 143 engages the top flange surface 153 of the nut 151, FIGURE 1A. The spring 142 holds the protective sleeve 135 at its upper end position on the valve member over the ring seal 134 to protect the seal from the erosive effects of well fluids flowing upwardly around the nose member and portective sleeve into the ports 130 of the valve member from which the fluids flow, as previously described, through the mandrel ports 102 and the landing nipple ports 103 into the annular space 181 toward the surface. Thus, the ring seal 133 is protected by the sleeve 135 during both the closing and opening of the subsurface safety valve and while the valve is open.

The subsurface safety valve is readily removed from its landing nipple with a suitable pulling tool supported on a tubing string or on a wireline. The upper flange 42 of the dog expander 41 is engaged, the dog expander is lifted upwardly shearing the pin 43 releasing the dog expander for upward movement relative to the mandrel and dog retainer whereby the cam surfaces on the dog expander holding the dogs outwardly are moved upwardly from behind the dogs releasing the dogs for inward movement so that further upward force on the safety valve cams the dogs to their retracted position releasing the safety valve which is then lifted back to the surface.

It will now be seen that a new and improved well tool has been described and illustrated.

It will be further seen that a new and improved subsurface safety valve has been described and illustrated.

It will also be seen that the safety valve is remotely controlled by control fluid supplied under pressure from the surface.

It will additionally be seen that the safety valve is biased toward an open position by control fluid pressure applied to first surface portions of a movable valve member while the valve member is biased toward a closed position by a force resulting from well fluid pressure on the valve member over second surface portions.

It will be further seen that a new and improved subsurface safety valve includes a ring seal protected from well fluids by a retractable protective sleeve or sheath which covers the ring seal when the valve is at an open position and is retracted from the ring seal as the seal moves to its sealed relationship with a bore surface of the valve when the valve moves to closed position.

It will also be seen that the relationship between the valve member and protective sleeve permits the ring seal to be moved into the sleeve in opening the valve before the sleeve is exposed to well fluids.

It will be further seen that the valve is moved to and held at an open position by a control fluid pressure and is moved to a closed position by well pressure upon reduction of the control fluid pressure.

It will also be seen that the subsurface safety valve is supported in a landing nipple which includes a control line portion through which control fluid is directed to the safety valve within the landing nipple independently of central and concentric flow passages within the landing nipple.

It will also be seen that the-subsurface safety valve includes a valve member movable along a'longitudinal axis and held against rotation relative to its axis by a U-shaped guide member which spans a reduced intermediate portion of the valve member.

FIGURES and 10A, taken together, illustrate an alternate well flow system utilizing the subsurface safety valve 20 wherein control fluid is directed from the surface to the safety valve through an annular flow passage while well fluids are produced within a central flow passage extending concentrically within the annular flow passage. Referring to FIGURE 10, inner and

outer tubing strings

300 and 301, respectively, are supported in concentric spaced relationship from the surface defining a central flow passage 302 for well fluids through the inner tubing string and an annular flow passage 303 for control fluid between the inner and outer tubing strings. The inner tubing string is threaded into an inner coupling 304 while the outer tubing string is similarly threaded into an outer coupling 305. The bore of the coupling 305 is reduced and threaded along a lower portion 305a which is connected on the inner coupling 304. The upper portion of the outer coupling is spaced from the inner coupling defining a lower end portion 303a of the control fluid flow passage 303. The outer coupling is secured along a lower end portion 305b of reduced Wall thickness to a landing nipple 310 comprising an inner tubular member 311 and a concentrically positioned spaced outer tubular member 312. The landing nipple members are connected at their lower ends to a coupling 313, FIGURE 10A, which is threaded along its lower end portion to a lower tubing string 314 extending downwardly to conduct well fluids to the landing nipple from below the safety valve. The tubular members of the landing nipple are spaced to define an annular flow passage 315 through which well fluids flow upwardly from the flow control portion of the safety valve by-passing the operating assembly portion of the safety valve. The inner tubular member 311 has lower ports 320 and upper ports 321 so that fluid passing through the safety valve existing through its mandrel ports 102 enters the annular landing nipple flow passage 315 through its lower ports passing upwardly along the safety valve and re-entering the inner tubular member through its upper ports. The well fluids flow upwardly through the coupling into the central flow passage 302 of the tubing string 300 to the surface.

The coupling 313 has an enlarged bore portion 322 for permitting well fluids from the lower tubing string to flow through the coupling around the valve nose member 154 into the valve member ports 130, as previously described. The inner tubular member 311 of the landing nipple has an internal annular locking recess 323 for receiving the locking dogs 33 on the safety valve and also has an internal annular recess 324 to receive control fluid from the surface directed into the safety valve, as previously described and illustrated. The control fluid flows into the recess 324 through an L-shaped flow passage 325 in a fitting 330 secured to the tubular member 311. The tubing section 331 extends from the fitting 330 in the flow passage 315 into the outer coupling 305 to which it is secured in seal tight relation, as by welding, and communicates at its upper end with the lower end portion 303a of the annular control fluid flow passage 303. Control fluid is directed from the surface to the safety valve through the flow passage 303 and its lower end portion 303a, the tubing portion 331, and into the fitting 330 from which the control fluid flows laterally inwardly into the landing nipple inner tubular member 11 in its recess 324. 'The control fluid then flows into the valve 20 through the port 61 as discussed above.

The coupling 313 has an internal annular upwardly divergent shoulder surface 332 which is engaged by the shoulder surface 105 of the mandrel of the safety valve supporting the safety valve in the landing nipple. The upper end of the landing nipple annular flow passage 315 is sealed by the coupling 305 which has the reduced wall section 305b extending downwardly telescopically between the inner and outer tubular members of the landing nipple. Similarly the coupling 313 has an upwardly extending end portion 313a of reduced wall thickness secured :between the lower end portions of the

tubular members

311 and 312. The annular flow passage 315 extends only between the

tubular members

311 and 312 from the coupling portion 305k at the upper end to the coupling portion 313a at the lower end. The lower end wall portion 305a of the coupling 305 is solid except for the tubing portion 331 for the control fluid.

The safety valve is installed in and removed from the landing nipple 310 and functions exactly as de scribed above in the landing nipple system of FIGURES 1 and 1A. The only functional difference between the flow systems of FIGURES 10A and FIGURES l and 1A is the flow path traversed by the control fluid between the surface and the landing nipples. In all other respects the system of FIGURES 10 and 10A, including the subsurface safety valve, functions exactly as described above.

It will now be seen that an alternate well flow system employing a subsurface safety valve embodying the invention includes a landing nipple and related structure providing an annular control fluid flow passage extending from the surface around a central well fluid flow passage connected with a landing nipple for supporting the safety valve. The landing nipple includes inner and outer tubular members defining an annular flow passage for directing well fluid along the safety valve into the central flow passage extending to the surface and including a short tubing section for directing control fluid from the annular flow passage from the surface into the subsurface safety valve.

Another well flow system wherein control fluid is directed from the surface in a central flow passage while well fluids are produced in an annular flow passage around the control fluid flow passage is illustrated in FIGURES 11 and 11A. Referring to FIGURE 11, inner and

outer tubing strings

335 and 336, respectively, are supported in concentric spaced relationship extending from the surface and defining a central flow passage 337 for control fluid and an annular flow passage 338 for well production fluids. The inner and outer tubing strings are connected into a coupling 339. The inner tubing string is connected into a lower reduced bore portion 339a of the coupling so that the coupling supports the tubing strings in their concentric spaced relationship whereby the annular flow passage 338 extends to the upper end of the reduced bore portion 339a of the coupling. The coupling has a lower reduced wall portion 33% which telescopes between inner and outer

tubular members

340 and 341 of a landing nipple 342 and is secured in sealed relation to the inner member 340 as by welding. The tubular members are similarly connected at their lower ends to a coupling 343 which has an upper reduced wall portion 343a extending telescopically between the lower end portions of the tubular members. The outer tubular member is suitably secured as by welding at 344 to the coupling. The concentric spaced relationship of the inner and outer

tubular members

340 and 341 defines an annular flow passage 345 for well fluids discharged through the valve ports 102 and flowing into the annular flow passage through lower ports 346 in the inner tubular member.

The portion 339a of the coupling 339 has a plurality of longitudinal, circumferentially spaced, flow passages 347 communicating the annular flow passage 338 from the surface with the annular flow passage 345 of the landing nipple so that well fluids entering the flow passage 345 through the ports 346 from the subsurface safety valve flow to the surface through the coupling flow passages 347 and the tubing string annular flow passage 338. The lower coupling 343 is connected with a lower tubing string 348 extending downwardly to a producing formation, not shown.

The inner tubular member 340 of the landing nipple 342 is provided with an internal annular locking recess 349 for receiving the locking dogs of a subsurface safety valve while the coupling 343 of the landing nipple has an internal annular upwardly divergent shoulder surface 350 for supporting the safety valve in the landing nipple.

A subsurface safety valve 20A is releasably locked within the inner tubular member 340 of the landing nipple 342. The safety valve is a modified form of the safety valve 20 adapted to function responsive to control fluid directed downwardly through its central bore as distinguished from lateral introduction of the control fluid through the port 61 in the spacer ring 54 as done in the valve 20. The safety valve 20 is modified to provide the valve 20A by removal of the bore plug 100 from the bore 101 of the mandrel 24. The safety valve 20A is identical to the safety valve 20 in all structural features other than the absence of the bore plug 100. Since the inner tubular member 340 of the landing nipple 342, FIGURE 11, is solid along the packing assembly 31, the lateral port 61 in the spacer ring 54 does not function in the safety valve 20A when set in the landing nipple 342. While control fluid in the central bore of the safety valve passes outwardly in the port 61 the control fluid pressure also is present above the upper packing portion 31a.

The safety valve 29A is inserted into and removed from the landing nipple 342 utilizing the same running and pulling tools operated in exactly the same manner as described above in connection with the handling of the safety valve 20. Control fluid is directed to the safety valve through the inner central flow passage 337 through the tubing 335 from a surface control fluid unit, as previously discussed. The control fluid flows downwardly through the flow passage entering the upper end of the safety valve and the bore of its mandrel 24 passing downwardly through the bore 100 into the bore portion 64. The control fluid flows from the bore portion 64 of the mandrel into the bore 92 of the stem of the valve member, FIGURE 2, through which the control fluid flows downwardly to the lower end of the stem bore where it passes laterally outwardly into the enlarged bore portion 95 of the mandrel. The pressure of the control fluid applies a downward force on the valve member over an effective area defined within the line of sealing engagement between the ring seal 121 and the wall surface defining the bore 95 in the valve mandrel. The valve member is biased upwardly by the pressure of the well fluids. When the safety valve is at its open position, well fluids flowing upwardly pass around its nose member 154 entering the lower mandrel bore flowing along the valve member and exiting outwardly from the safety valve through its lateral ports 102 and the landing nipple ports 346 entering the lower end portion of the annular flow passage 345. The fluids flow along the landing nipple in the annular flow passage upwardly into the longitudinal flow passages 347 in the coupling 339. The well fluids flow into the annular flow passage 338 through which they flow to the surface. Thus, control fluid is applied through the central flow passage 337 from the surface to the safety valve while well fluids are produced from the safety valve through the annular flow passage 338, The safety valve 20A functions in all respects identically, as described above, to the valve 20 other than the manner of the entry flow path of its control fluid.

It will now be seen that a new and improved alternate form of subsurface safety valve and well flow control system has been described and illustrated. In the alternate form of safety valve and well flow system, control fluid is introduced into the safety valve through a central flow passage in a tubing system extending to the surface and into the safety valve itself through a central flow passage.

Another form of subsurface safety valve 360 is shown in FIGURE 12 releasably locked in the landing nipple 21. The valve 360 comprises a central packing section 364, a valve section 365, and an upper locking assembly 370. The upper and lower external annular packing recesses 371 and 372 of the mandrel 373 receive the

packing assemblies

374 and 375, respectively. The upper and lower recesses are open at their upper and lower ends, respectively, to allow the packing assemblies to be placed onto the mandrel. The packing assemblies form upper and lower seals around the mandrel with the wall of the bore of the landing nipple above and below its recesses 62. Control fluid passes inwardly from the recess 62 through one or more radial flow passages 381 of the mandrel.

The locking assembly 370, shown partially in enlarged form in FIGURE 13, is secured on the upper reduced section 364a of the mandrel. The upper packing assembly 374 is held on the mandrel by a retainer 382 threaded on the upper reduced section of the mandrel and held in place by a finned nut 383 threaded on the upper end section of the mandrel and having longitudinally extending circumferentially spaced

fins

384 and 393. Each of the fins 384 projects into a recess 385 in the downwardly extending collet fingers 390 formed on a collet ring 391. The collet fingers at the lower ends of the slots 385 are engaged by the lower ends of the fins 384 to hold the collet fingers against upward movement while the lower ends of the collet fingers engage the upwardly facing shoulder 382a of the retainer which holds the collet fingers against downward movement and therefore limits the collet fingers to lateral expansion and contraction only. The collet fingers are separated from each other by the downwardly opening recesses 39017.

In the position shown in FIGURE 12 the outer bosses 390a on the collet fingers are held in the locking recess 34 to lock the valve within the landing nipple. The collet fingers are held in the expanded position by the locking fingers 391a which are formed on and extend downwardly from the annular ring 392. The locking fingers are spaced around the ring 392 separated by the downwardly opening slots 384a and fit within the collet fingers between the fins 384 so that they may be raised and lowered to lock the collet fingers in the expanded position and to permit the collet fingers to be retracted inwardly around the upper reduced section of the retainer 382. As shown in FIGURE 12 the locking fingers are in the downward position between the heads of the collet fingers and the reduced upper section 382b of the retainer 382. Each of the locking fingers extends circumferentially a sufficient distance that half of each finger is positioned behind half of one of the collet fingers while the other half of the locking finger is positioned behind half of an adjacent collet finger. Thus each of the locking fingers fits behind portions of two of the collet fingers and therefore adjacent locking fingers cooperate to expand each of the collet fingers. The locking fingers are held around the nut 383 by the radial fins 393 on the nut and received in the longitudinally extending slots 394 formed in each of the locking fingers. Each of the fins 393 is evenly spaced between the fins 384. The fins 393 are somewhat shorter in longitudinal length than the fins 384 and their length is so related to the length of the slots 394 that the locking fingers cannot be pulled off thenut 383 but may be lifted sufficiently to withdraw the fingers 391 from within the heads of the collet fingers 390 to allow the collet fingers to be cammed inwardly around the reduced section 382b of the retainer 382 so that the valve 300 may be released and removed from the bore of the nipple. Thus the lower ends of the fins 384 limit the upward movement of the collet fingers while the lower end of the fins 393 limit the upward movement of the locking fingers. The retainer 382 also serves to limit the upward movement of the packing assembly 374 of the mandrel.

The upper end section of the mandrel 373 is provided with a laterally extending slot 395 which functions with a valve running tool to maintain the proper orientation of the valve while installing it in the landing nipple.

The mandrel 373 has a downwardly opening bore 400 in which a valve element neck 452 of a valve element 453 is slidably fitted. The neck 452 is bifurcated along substantially the upper half of its length to form a longitudinally extending slot 455 which receives the guide pin 460 so that the neck and valve element will be properly oriented and will'not rotate within the sleeve and mandrel. The guide pin isfitted in the lateral bore 404 through the mandrel. The slot 455 is of suflicient length to permit the necessary longitudinal movement required for the valve element to move between open and closed positions. The mandrel 373 has a hole 400a and the neck 452 has a similar hole 455a alignable with the hole 400a when the 18 valve member is at a partially open position to receive a shear pin, not shown, pinning the valve at such position so that liquid in the tubing string is not compressed below the valve as it is moved to its seat position in the landing nipple.

Thereduced upper portion 461 of the valve element is threaded into the lower end section of the neck and both the neck and the valve element are provided with a longitudinal bore 462 which communicates with a lateral port 463 to allow fluid to flow downwardly through the neck and the upper end portion of the valve element and laterally outwardly from the valve element into an annular space 464 between the sleeve 454 and the reduced portion of the valve element in which an annular piston 456 is disposed for longitudinal movement. Inner and outer ring seals 457 and 458 are disposed in inner and outer annular recesses in the piston for sealing around the valve member neck portion and within the sleeve 454. The piston 456 functions in the operation of the valve member responsive to control fluid pressure as discussed below. The sleeve 454 is threaded on an adapter 451 which in turn is threaded on the lower end of the mandrel 364. The sleeve is reduced internally to provide the upwardly facing internal annular shoulder 465 which limits downward movement of the annular piston 456 within the sleeve. Upward movement of the annular piston is limited by the lower end of the adapter 451. The lower end of the neck member 452 engages the inwardly extending internal annular flange 451a on the adapter to limit the downward movement of the neck member and valve element. The sleeve 454 is reduced along a central section to provide annular space around the sleeve within the bore of the landing nipple to facilitate movement of well fluids through the sleeve toward the landing nipple ports 103. An external annular flange 470 provides a downwardly facing annular shoulder 471 which seats on the internal annular shoulder of the landing nipple to limit the downward movement of the safety valve within the bore of the nipple. Annular ring seals 272 are positioned around the lower end section of the sleeve to seal between the sleeve and the bore surface of the landing nipple below its shoulder .110. The enlarged central section 474 of the valve element is provided with a transverse longitudinally extending substantially rectangular slot 475 which is sufliciently long that fluids may flow into it below the lower end of the valve sleeve 454 when the valve is in open position, through the slot within the sleeve to the upper end portion of the slot where the slot opens into lateral ports 480 in the sleeve 454 through which the fluids flow into the landing nipple around the sleeve and outwardly from the landing nipple through the ports 103. The lower end section of the valve element includes a reduced section 481 and a cap member 482 which is threaded on the lower portion of the section 481. An enlarged upper bore portion 483 of the cap receives a spring 484 confined within the cap between the cap and the lower face of a protector sleeve 485 which telescopes upwardly over a lower end portion of the central section 474 of the valve element. The sleeve 485 is biased by the spring 484 upwardly over a ring seal 490 fitted in an external annular recess formed around the portion 474 of the valve element near its lower end. An upwardly extending annular flange 492 formed on the upper end of the cap member 482 forms an upwardly opening recess into which the sleeve 485 is movable against the force of the spring 484. An upper downwardly divergent end surface 294 on the cap member is engageable with a lower downwardly divergent seat surface 495 on the lower end of the sleeve 454 to close the valve against fluid flow when the valve element is in an upper position. When the valve element moves upwardly until the surface 494 engages the seat 495, the upper end of the sleeve 485 is depressed downwardly by the seat surface with the sleeve 485 being received within the recess 493 and thus uncovering the ring seal 490 so that it may seal between the bore of the sleeve 454 and the outer surface of the central portion of the valve element to close the valve. The sleeve 485 is biased upwardly over the ring seal by the spring 484 when the valve is in open position to maintain the size and shape and to protect the ring seal against fluid erosion. The sleeve also minimizes throttling around the ring seal when moving the ring seal downwardly away from the valve sleeve into the sleeve 485. The upper end of the sleeve 485 continues to seal to some extent with the seat surface 495 as the ring seal is moved downwardly by the valve element with the sleeve. When the lower end of the valve section 474 engages the sleeve 485 the sleeve is forced downwardly from the seat surface 495 with the seal 490 protected within the sleeve.

The primary function of the annular piston 456 is to reduce the control fluid pressure required to open the valve. With the valve at its closed position the well fluid pressure within the tubing string at the coupling 190 acts on the valve to hold it closed over an effective area defined by the line of sealing engagement of the O-ring 490 with the wall of the bore of the sleeve 454. When the control fluid pressure is raised to open the valve its acts downwardly over an effective area of the valve defined by the line of sealing engagement of the outer ring seal 458 on the annular piston with the inside wall of the upper section of the sleeve 454 which is a somewhat larger area than that acted upon by the well fluids holding the valve closed. The provision of the annular piston therefore minimizes the control fluid pressure required to open the valve. The control fluid pressure acting on the upper end of the piston forces the piston downwardly also moving the valve element downwardly due to the engagement of the lower end of the piston with the external annular shoulder 453a on the valve element. When the annular piston reaches its lower limit of travel by engaging the internal annular shoulder 465 within the sleeve 454, the valve is partially open with its ring seal 490 having been moved downwardly out of engagement with the bore wall of the sleeve 454. With the valve partially open the well pressure from below the valve now acts upwardly against an effective area of the valve element defined by the line of sealing of the inner ring seal 457 with the outside of the valve element above the flange 453a. The annular cannot move farther downwardly and thus the control fluid pressure acts downwardly on the same effective area of the valve element within the inner ring seal 457 moving the valve element to its full open position with the valve element being held against further downward movement by the engagement of the lower end of the neck 451 with the internal annular flange 451a. Thus, the annular piston aids in the opening of the valve by providing a larger area for the control fluid pressure to act on to initiate the valve opening than is exposed to the control fluid pressure when the valve is at a full open position.

When the control fluid pressure is reduced or the well fluid pressure increases until the upwardly acting pressure on the valve element over the effective area defined by the inner ring seal 457 exceeds the downwardly acting control fluid pressure over an equivalent effective area, the valve element moves upwardly toward the closed position. When the flange 453a engages the lower end of the piston the valve will be partially open and the valve element starts lifting the piston back upwardly. The dampening effect of the control fluid acting on the upper surfaces of the annular piston over an area defined by the line of sealing of the outer ring seal 458 with the inside of the sleeve prevents the valve from sudden closure or snap action.

The safety valve 360 is installed in and removed from the landing nipple with suitable running and pulling tools such as described in the patent application Ser. No. 471,995, supra. The running tool 460 of the previously filed application is primarily designed for the insertion and removal of a safety valve supported in a side pocket or laterally misaligned landing nipple pocket though such running and pulling tool is also readily usable in a system as shown herein in FIGURE 12, since the misalignment structure of the running tool 460 is simply held in a substantially straight line relationship by the flow passage walls as the running tool and safety valve are lowered into or removed from the landing nipple. It will be clear, also, that the running tool 460 may be altered for use with the safety valve 360 of the present application by suitably securing the

assemblies

461 and 462 of the running and pulling tool in a fixed straight line relationship as by suitable immobilization of the connections between the rod 463 and the

assemblies

461 and 462 since lateral displacement of the running tool is not necessary with the bore of the landing nipple in FIGURE 12 being oriented along the longitudinal axis of the tubing string through which the safety valve 360 is installed and removed.

Preparatory to insertion of the safety valve 360 into the tubing string for installation in its landing nipple, the valve is shear pinned at a partially open position by raising its valve member 453 relative to its mandrel until the valve member hole 455a in its neck portion is aligned with the mandrel hole 400a. A shear pin, not shown, is inserted through the aligned mandrel and valve element holes to lock the valve member at the partially open position. The valve is then supported on its running tool and lowered into the landing nipple. With the valve partially open the valve is moved downwardly to its seated position with its ring seals 472 moving into sealed relationship with the landing nipple bore below its shoulder \without compressing liquid present within the bore of the tubing string and landing nipple. When the safety valve is seated and locked in the landing nipple by its expanded locking fingers 390 which are received within the locking nipple recess 34, the control fluid pressure communicated to the valve through the line 23 is raised to a predetermined value for releasing the valve element 453 to move toits full open position. The control fluid pressure is transmitted from the control line 23 through its fitting and the lateral port 63 in the landing nipple into the internal annular recess 62 which encompasses the valve between its upper and

lower packing sections

371 and 372. The control fluid pressure is transmitted into the valve through the port 381 traveling down-wardly through the bore 462 of the neck portion of the valve element and outwardly through the port 463 into the annular chamber 464 around the valve element above the annular piston 456. At the partially open position at which the valve element is pinned the piston 456 is already at the lower end of its travel engaged with the shoulder 465 so that the pressure of the control fluid is effective on the valve element over a net area defined by the line of sealing engagement of the inner ring seal 457 with the outer wall surface of the neck of the valve element applying a downward force to the valve element. When the control fluid pressure reaches a Sllfi'lcifl'lt magnitude the shear pin-through the holes 400a and 4550 is severed releasing the valve element so that it is forced downwardly to its fully open position as illustrated in FIGURE 12. At such position as Well fluid pressure is applied upwardly on the valve element over an effective area also defined by the line of sealing engagement of the ring seal 457 and the neck section of the valve element engaged by the ring seal. So long as the control fluid pressure remains at a sulficient level above the well fluid pressure the valve is held at its full open position so that well fluids flow upwardly around the nose member 482 into the valve member longitudinal slot 475 through which the fluids then flow upwardly exiting from the upper portion of the slot through the ports 482 into the landing nipple inner tubular member from which the fluids flow radially outwardly through its ports 103. The well fluids then flow upwardly through the landing nipple annular flow passage 181 flowing back inwardly into the central flow passage above the safety valve through the upper landing nipple ports 182. The Well fluids then flow to the surface through the tubing string 22 connected with the landing nipple as shown in FIGURE 1. During the flow of the well fluids through the safety valve, the ring seal 490 of the safety valve is protected by the sleeve 485 which is biased upwardly telescoped over the ring seal by the spring 484 confined between the cap 482 and sleeve 485, FIGURE 12.

When the control fluid pressure is reduced by either a controlled reduction from the surface control unit or a rupture of the supply line or surface equipment connected with the tubing 23, the force of the well fluid pressure lifts the valve element to its closed position to prevent further flow of well fluids through the tubing string above the safety valve. As the valve element moves upwardly, the upper end surface of the sleeve 485 engages the seat surface 495 on the lower end of the sleeve 454 while the valve element continues upwardly compressing the spring 484 as the ring seal 490 is withdrawn from within the sleeve 485 into the bore of the valve sleeve above the seat surface 495. The valve element moves upwardly until the upper end edge surface 494 of the cap 482 engages the seat surface 495 at which position the valve is fully closed. During the latter stages of the upward movement of the valve element, the shoulder surface 4530: on the valve element engages the lower end surface of the annular piston 456 which is exposed to control tfluid pressure over its upper surfaces above the ring seals 457 and 458. The sudden increase in effective area of the valve element exposed to control fluid by lifting the annular piston 456 provides an increase in the downward force applied by the control fluid opposing the upward movement of the valve element toward its closed position whereby the movement is somewhat dampened causing the valve element to slowly move to its fully closed position.

When reopening of the safety valve 360 is desired, the control fluid pressure as transmitted through the line 23 is increased to force the valve element back downwardly to its open position. The control fluid pressure acts on both the valve element and the annular piston 456. At the maximum upper end or closed position of the valve element, the lower end surface of the annular piston 456 is engageable with the shoulder 453a on the valve element so that the downward force of the control fluid pressure is effective to force the valve element downwardly over an area defined by the line of sealing engagement of the outer ring seal 458 on the annular piston with the inner wall surface defining the bore of the sleeve 454 above its shoulder 465.

The control fluid pressure forces the annular piston 456 and the valve element downwardly breaking the seal between'the cap member end surface 494 and the sleeve member end surface 495. The annular piston and valve element move downwardly until the annular piston engages the internal shoulder surface 465 in the sleeve 454 at which position the valve element is slightly open having been moved downwardly a short distance by the maximum force supplied by the pressure of the control fluid acting over the full area of the annular piston. After the lower limit of travel of the piston 456 is reached, it is held against further downward movement with the valve element continuing to be forced downwardly by the control fluid pressure acting over the effective area of the valve element defined by the line of sealing engagement of the inner ring seal 457 with the outer wall surface of the valve element neck. As the valve element moves downwardly the ring seal 490 is moved into its protective sleeve 485 which is biased upwardly against the shoulder surface 495 by the spring 484. When the lower end surface of the portion 474 of the valve element is fully telescoped into the sleeve 485 further downward movement of the valve element carries the sleeve 485 downwardly from the shoulder surface 495 with the protective sleeve remaining biased upwardly over the ring seal 490 as the valve element is moved to and held at its full open position, FIGURE 12. The valve element remains biased downwardly and held at such open position by the downward force of the control fluid acting over the net effective area defined within the inner ring seal 457 while the same net effective area below the ring seal is exposed to the well fluid pressure biasing the valve upwardly. So long as the control fluid remains at a pressure in excess of the well fluid pressure the valve is thus held at its open position. The annular piston provides a large effective area exposed to the control fluid pressure for breaking the initial seal when the pressure drop across the valve element is at its maximum and moving the valve to a partially open position. The pressure drop across the valve is reduced and the valve is moved farther to its full open position by the control fluid acting over the smallereffective area within the inner ring seal of the annular piston.

It will now be seen that a still further form of a new and improved subsurface safety valve has been described and illustrated.

It will be seen that an annular piston is included in the valve for providing a maximum effective cross sectional area to move the valve during its initial stages of opening from a closed to a partially open position at the time when a maximum pressure drop in the well fluids is imposed across the valve. The annular piston travels downwardly only a portion of the stroke of the main valve element so that the latter stages of the opening of the valve element when the pressure differential across the valve from the well fluids is substantially reduced is effected by control fluid pressure applied over a smaller area than provided when the annular piston is acting on the valve element.

It will be also seen that the valve element includes a ring seal protectable by a sleeve biased over the ring seal by a spring when the valve element is at its lower open position and telescopically retractable from over the ring seal against the force of the spring when the valve element moves back upwardly to its closed position.

It will further be seen that the piston structure of the valve illustrated in FIGURE 12 makes it possible for the valve to be of relatively short length and be operable by a relatively small volume of control fluid delivered thereto which is desirable in installations where the speed of operation of the valve is of importance or Where the surface control means which provides the control fluid is of relatively small capacity and can deliver only a limited volume of control fluid.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool comprising: a body having a flow passage with an inlet and a longitudinally spaced lateral outlet; valve means in said body having a flow passage therein with a lateral inletand a longitudinally spaced lateral outlet and having a closure member, said valve means being movable between a first position in which said closure member closes said body inlet and a second open position in which said lateral inlet of said valve means is open and said lateral outlet of said valve means is in flow communication with the lateral outlet of said body for controlling fluid flow through said flow passage of said body; said valve means having first surface portions for application of fluid pressure thereto for biasing said valve means toward said open position; means for imposing fluid pressure on said first surface portions independently of the pressure of the fluid controlled by said valve means; and said valve means having second surface portions for application of said pressure of said fluids controlled by said valve means for biasing said valve means toward said closed position.

2. A valve device comprising: an elongate valve housing open at one end; lateral port means in the wall of said housing spaced from said open end and with said open end providing fluid passage means through said housing; an elongated valve element slidably positioned in said housing and movable longitudinally therein between an open position and a closed position to control the flow of fluid through said fluid passage means; said valve element comprising means enclosing one end thereof and a skirt portion extending therefrom and having lateral port means therein in constant communication with said lateral port means of said housing; a valve seat adjacent the open end of said housing; and a valve closure affixed. to the skirt portion of said valve element disposed outwardly therefrom and adapted to sealingly contact said seat to close said open end of said housing, said closure being spaced from said valve seat when said valve element is in said open position.

3. A valve device comprising: an elongate valve housing open at one end and having lateral port means in the wall thereof, said lateral port means and said open end of said housing providing flow passage means through said housing; an elongate valve element slidably positioned in said housing and movable between an open position and a closed position to control the flow of fluid through said housing flow passage means; said valve element comprising piston means at one end thereof and an elongate central portion extending from said piston means and having means providing passage means in said housing flow passage means between the housing and said central portion in constant communication with said lateral port means of said housing; a valve seat adjacent the open end of said housing; and a valve closure means aflixed to the end of said central portion of said valve member opposite said piston and adapted to engage said seat to close said open end of said housing to cut off flow therethrough, said closure being spaced from said seat when said valve is in said open position.

4. A valve device as defined in claim 3 wherein said piston means has seal means sealing around said piston means within said housing separating first surface portions of said valve element from second surface portions of said element, said second surface portions being in communication with said housing flow passage means, and further flow passage means in said housing in communication with said first surface portions.

5. A valve device as defined in claim 3 including seal means on said valve element for sealing with said housing between said open end and said lateral port means and a sleeve movably supported on said valve element for covering said seal means when said valve element is at said open position and adapted to retract from said seal means when said seal means is moved into sealing engagement with said housing.

6. A well tool as defined in claim 5 including an annular piston disposed within said housing around said valve element, said annular piston having surface portions exposed to control fluid for moving said valve element an initial portion of the distance between said closed position and said open position.

7. A valve device as defined in claim 5 wherein said piston means has seal means sealing around said piston means within said housing separating first surface portions of said valve element from second surface portions of said element, said second surface portions being in communication with said housing flow passage means, and further flow passage means in said housing in communication with said first surface portions.

8. A valve device as defined in claim 5 wherein said valve closure means is movable relative to said seal means, said closure means sealing with said valve seat when said valve element is at said closed position, said closure means being adapted to receive said seal means and said sleeve in telescopic relationship and said closure means being adapted to remain in said sealed relationship with said valve seat until said seal means and said sleeve are moved into said closure means during movement of said valve element from said closed position to said open position.

9. A valve device as defined in claim 8 wherein said piston means has seal means sealing around said piston means within said housing separating first surface portions of said valve element from second surface portions of said element, said second surface portions being in communication with said housing flow passage means, and further flow passage means in said housing in communication with said first surface portions.

10. A Well tool as defined in claim 9 wherein said closure means is provided with a seat surface for sealing with said open end of said housing and an annular skirt portion for receiving said sleeve on said valve element while said valve element is at said closed position and including resilient means for biasing said sleeve toward said seal means on said valve element.

11. A valve device as defined in claim 10 wherein said passage means in communication with said first surfaces of said valve element includes lateral port means for receiving control fluids flowing radially inwardly from passage means in a landing nipple supporting said valve device.

12. A Well tool as defined in claim 10 wherein said passage means in communication with said first surfaces of said valve element includes a central longitudinal flow passage extending into said housing from the other end thereof.

13. A valve device for controlling the flow of a fluid through a conduit, said device comprising: a tubular valve housing open at one end to place the interior thereof in flow communication with said fluid; housing port means in the wall of said housing communicating the interior with the exterior thereof; a sleeve element slidably positioned in said housing adjacent said housing port means, said sleeve element having one end open to said fluid and being enclosed at the opposite end; sleeve port means in the wall of said sleeve element, said sleeve port means being in constant flow communication with said housing port means; sealing means between said housing and said sleeve element on the opposite side of said port means in said housing from said open end of said housing; valve seat means adjacent to open end of said housing; a valve cap member aflixed to said sleeve element and movable therewith to sealingly contact said valve seat means when said device is closed and being spaced from said valve seat means when said device is open to permit fluid flow through said device; and a tubular mandrel adapted to be installed in said conduit to form a portion thereof; mandrel port means in the wall of said mandrel; said housing being inserted in said mandrel so that said housing port means are in flow communication with said mandrel port means.

14. The device of claim 13 further including means for applying pressure against the closed end of said sleeve element to resiliently maintain said device in the open position during normal operation.

15. A valve device comprising: an elongated tubular valve housing, said housing being open at one end; housing port means in the wall of said housing; an elongated sleeve element slidably positioned in said housing to slide longitudinally therein between an open position and a closed position to control the flow of fluid through said housing port means; said sleeve element comprising a stem member enclosing one end thereof and a skirt member extending from said stem member toward said open end; a valve seat adjacent the open end of said housing; a valve cap aflixed to said sleeve element extending therefrom outwardly of said skirt member to sealingly contact said valve seat and to close said open end of said housing and being spaced from said valve seat when said sleeve element is in said open position.

16. The device of claim 15 wherein said skirt member is provided with sleeve port means constantly registrable with said housing port means.

17. A valve device for controlling the flow of a fluid through a conduit, said device comprising: a tubular valve housing open at one end to place the interior thereof in fl'uid communication with said fluid; housing port means in the wall of said housing communicating the interior with the exterior thereof; a sleeve element slidably positioned in said housing adjacent said port means, said sleeve element having an opening adjacent one end open to said fluid and being enclosed at the opposite end; sleeve port means in the wall of said sleeve element, said sleeve port means being in continuous flow communication with said housing port means; sealing means between said housing and said sleeve element; valve seat means adjacent the open end of said housing; a valve cap member aflixed to said sleeve element and movable therewith to sealingly contact said valve seat means and being spaced from said valve seat means when said sleeve element is in open position to permit fluid flow through said device.

18. The device of claim 17 further including a tubular mandrel adapted to be installed in said conduit to form a portion thereof, mandrel port means in the wall of said mandrel port means in the wall of said mandrel, said housing being inserted in said mandrel so that said housing port means are in flow communication with said mandrel port means.

19. The device of claim 18 further including means for applying pressure against the closed end of said sleeve element to resiliently maintain said device in the open position during normal operation.

20. A subsurface safety valve comprising: an elongated tubular mandrel adapted to be connected into a string of well conduit to form a portion thereof; mandrel port means in the wall of said mandrel; a tubular valve housing insertable in said mandrel and provided with housing port means in the wall thereof communicating with said mandrel port means; upper and lower sealing means between the inner wall of said mandrel and the outer wall of said housing on either side of said port means; the lower end of said housing being opened to communicate the interior of said housing with the interior of said mandrel below said lower sealing means; a sleeve element slidably positioned in said housing, said sleeve element comprising a skirt member provided with sleeve port means communicating with said housing port means and means closing said skirt member above said port means; sealing means between said sleeve element and the inner wall of said housing above said housing port means; valve seat means adjacent the lower end of said housing; a valve cap aflixed to said sleeve element and movable therewith, said valve cap being disengaged from said valve seat means when said valve device is in the open position and being sealingly engaged with said valve seat means when said valve device is in the closed position; and stop means in said housing for limiting the sliding travel of said sleeve element therein.

21. The valve of claim 20 further including means for maintaining pressure in said mandrel above said sealing means of said sleeve element to resiliently maintain said valve in the open position during normal operation.

22. A well production valve adapted to be positioned within a bore forming a flow passage to prevent fluid flow from the upper end of said bore and divert fluid flow entering the lower end of said bore laterally outwardly through a side port communicating with said bore, said valve comprising: a mandrel; locking means secured on the upper end of said mandrel for detachably locking said valve in said bore; packing means secured around said mandrel for sealing between said mandrel and the wall forming said bore; said mandrel being provided with a downwardly opening central bore and means providing flow passages through said mandrel into said central bore;

a sleeve secured on the lower end of said mandrel extending downwardly therefrom, said sleeve having a lower end annular seat surface; packing means secured around said sleeve near the lower end thereof; a longitudinally movable valve element disposed through said sleeve into said downwardly opening bore of said mandrel, said valve element having an upper end section slidably disposed in said bore of said mandrel, a central piston section the outer cylindrical surface of which is spaced apart within said sleeve forming an annular cylindrical chamber within said sleeve around said valve element, a port section having an elongated transversely extending port partially alignable with said lateral ports through said sleeve, and a lower enlarged end section having an upwardly facing annular seat surface engageable with said seat surface on the lower end of said sleeve when said valve element is in closed position; said valve element having an external annular seal above said lower enlarged end section engageable with the inside surface of said sleeve when said valve element is in an upper closed position; sleeve means carried by said lower enlarged end section of said valve element for protecting said seal means around said valve element from direct contact with well fluids when said valve element is in a lower open position; an annular piston slidably disposed within said sleeve around said piston section of said valve element, said annular piston being adapted to engage said valve element to displace said valve element downwardly for opening said valve element responsive to pressure applied by control fluid within said annular chamber above said piston; and said upper end section of said valve element having flow passage means for conducting fluid flow from said bore of said mandrel downwardly through said valve element into said annular cylinder above said annular piston.

23. A well production valve adapted to be detachably secured within a bore forming a flow passage to prevent upward flow from said bore and direct fluid flow entering the lower end of said bore laterally outwardly from said bore through a lateral port communicating therewith, said valve comprising: a mandrel provided with a downwardly opening central bore; locking means secured on the upper end of said mandrel for detachably locking said valve within said bore; external annular packing engaged on said mandrel for sealing around said mandrel with a bore forming a flow passage in which said valve is positioned; a downwardly extending sleeve secured on the lower end of said mandrel, the lower end of said sleeve providing a downwardly facing annular seat surface; external annular packing means on said sleeve to seal with said wall forming said bore in which said valve is positionable; said sleeve having lateral ports above said packing means around said sleeve; a longitudinally movable elongate valve element positioned through said sleeve into said bore of said mandrel, said valve element having an upper end section slidably disposed within said bore of said mandrel, a piston section below said upper end section, said piston section having an outer cylindrical surface spaced apart within said sleeve forming an annular cylinder between said sleeve and said piston section; an annular piston slidably disposed within said annular cylinder adapted to engage said valve element for moving said valve element from a closed to a partially open position; said mandrel and said upper end section of said valve element being provided with fluid flow passage means communicating into said annular cylinder against the upper end surfaces of said annular piston for displacing said valve element downwardly with said piston responsive to said control fluid pressure; said valve element being further provided with a port section having an elongated lateral port communicating with said lateral ports through said sleeve, said lateral port in said valve element being in communication with said bore in which said valve is releasably locked below the lower end of said sleeve when said valve element is in a downward open position; said valve element being further provided with an enlarged lower end section forming an upwardly facing external annular seat surface engageable with said seat surface on the lower end of said sleeve when said valve element is in an upper closed position; said valve element having an external annular packing above said enlarged lower end section engageable with the inside wall of of said sleeve to seal between said valve element and said sleeve when said valve element is in an upper closed position; and a longitudinally movable sleeve carried by said lower end section of said valve element and adapted to be moved over said packing around said valve element when said valve element is in a downward position for protecting said packing from erosive effects of well fluids flowing around said valve element when. said valve element is in open position.

24. A well production valve adapted to be releasably locked within a bore forming a flow passage, said valve comprising: a mandrel provided with a downwardly opening bore; locking means engaged on the upper end of said mandrel for releasably locking said valve within said bore; upper and lower external annular packing engaged on said mandrel spaced apart from each other, the outside diameter of said packing being greater than the outside diameter of said mandrel between said packing thereby providing an annular space around said mandrel between said packing when said valve is releasably locked in said flow passage bore; said mandrel being provided with radial fluid flow passages extending into said bore of said mandrel between said upper and lower packing; a valve sleeve connected to and extending downwardly from said mandrel, said sleeve having a lower end annular seat surface around a longitudinal bore through said sleeve; external annular seal rings around said sleeve for sealing between said sleeve and the wall forming said flow passage bore; said sleeve having an external annular downwardly r facing shoulder above said packing rings to provide a seat surface for supporting said valve against downward movement in a flow passage bore having an internal annular shoulder to support said valve; an elongate valve element slidably positioned through said sleeve into said bore of said mandrel, said valve element comprising an upper end neck section slidable within said bore of said mandrel, a central piston section threaded along an upper end portion thereof into said neck section, said piston section being spaced apart within said sleeve below said mandrel forming an annular cylinder below said mandrel between said sleeve and said piston section of said valve element, said neck section and said piston section having flow passages communicating downwardly from said bore of said mandrel through said valve element into said annular cylinder to permit the control fluid pressure to be applied from said bore of said mandrel into said annular cylinder; said valve element including a ported section formed with said piston section below said piston section and having a diameter larger than said piston section thereby providing an upwardly facing shoulder on the upper end of said ported section, said ported section having an elongate lateral port therethrough, said port being sufficiently long to communicate with said lateral ports through said valve sleeve downwardly through said sleeve and below the lower end of said sleeve when said valve element is in a lower open position; said valve element being further provided with an enlarged lower end section secured on said ported section, said enlarged lower end section providing an upwardly facing external annular seat surface engageable with said seat surface on the lower end of said valve sleeve when said valve is in an upper closed position; an external annular seal ring secured on said valve element above said lower end section to seal with the inside surface of said valve sleeve forming said bore through said sleeve when said valve is in an upper closed position; said lower end section of said valve element having an upwardly opening annular chamber therein; an annular seal ring sleeve adapted to slide upwardly over said annular seal ring around said valve element to protect said seal ring when said valve element is in open position; a spring within said annular chamber of said lower end section of said valve element biasing said seal ring sleeve upwardly over said seal ring when said valve element is in a lower open position; the upper end of said seal ring sleeve being engageable by the lower end seat surface of said valve sleeve to depress said seal ring sleeve against said spring permitting said seal ring to engage said valve sleeve when said valve element is in the upper closed position to retract said sleeve from over said seal ring against said spring; and an annular piston slidably disposed within said annular cylinder between said valve sleeve and said piston section of said valve element, the lower end of said piston being engageable with the upper end of said ported section of said valve element to force said valve element downwardly to a partially open position responsive to control fluid pressure through said mandrel and said valve element into said annular cylinder.

25. A valve as defined in claim 24 wherein said valve element is held against further downward movement when in its full lower open position by a shoulder surface on the lower end of said neck section of said valve element and when said valve element is in said lower open position the upper end of said ported section of said valve element engageable by the lower end of said annular piston is spaced apart below said lower end of said annular piston, said valve element being moved to its full open position after initial opening by said annular piston by control fluid pressure acting on an effective area defined within a line of sealing engagement between said annular piston and said piston section of said valve element.

26. A valve as defined in claim 25 wherein the line of sealing engagement between the external surface of said annular iston with the bore through said valve element sleeve defines an effective area greater than the effective area within the line of sealing engagement between said seal ring on said valve element above said lower enlarged end section and the bore of said valve sleeve adjacent to the lower end of said sleeve.

27. A valve as defined in claim 26 including an elongated upwardly opening slot in the neck section of said valve element to receive a guide pin secured through said mandrel to maintain said valve element in alignment with said valve sleeve whereby said slot through said valve element registers with said slots through said valve sleeve.

28. A subsurface safety valve comprising: a tubular mandrel open at a first end provided with a valve seat surface at said first end thereof and port means spaced from said first end for communicating the interior and exterior of said mandrel; external annular seal means supported on said mandrel between said port means and said first end; said mandrel having an external annular shoulder seat surface between said seal means and said port means for supporting said safety valve in a well conduit landing nipple; locking means on said mandrel for releasably securing said safety valve in said landing nipple; external annular packing means 011 said mandrel between a second end of said mandrel and said mandrel port means; a valve element slidably positioned within the bore of said mandrel for movement between open and closed positions, said valve element having a piston portion supporting external annular seal means engageable with an inner wall surface portion of said mandrel defining a portion of said bore through said mandrel between said second end and said port means whereby control fluid pressure within said mandrel bore between said second end of said mandrel and said valve element piston portion biases said valve element away from said second end of said mandrel toward open position; said valve element having longitudinally extending passage means permitting fluid flow along said element from said first end of said mandrel to said mandrel port means when said valve element is at an open position relative to said mandrel; said valve ele-