US3457991A

US3457991A - Well tools

Info

Publication number: US3457991A
Application number: US706034A
Authority: US
Inventors: Phillip S Sizer; Donald F Taylor Jr
Original assignee: DONALD F TAYLOR JR; PHILLIP S SIZER
Current assignee: DONALD F TAYLOR JR; PHILLIP S SIZER
Priority date: 1968-02-16
Filing date: 1968-02-16
Publication date: 1969-07-29
Anticipated expiration: 1986-07-29

Description

July 29, 1969 P. s. SIZER ET AL 3,457,991

WELL TOOLS Filed Feb. 16, 1968 5 SheetsSheet 1 INVENTOR Donald F. Tpy|or,Jr. 4 Phillip S. S|zer Fig. I

BY M

ATTORNEY$ July 29, 1969 P. s. SIZER ET AL 3,457,991

WELL TOOLS I Filed Feb. 16, 1968 3 Sheets-Sheet 2 INVENTOR Donald F. Taylor, Jr.

Phillip S. Sizer w W BY July 29, 1969 p. 5, suz ET AL WELL TOOLS 3 Sheets-Sheet Filed Feb. 16, 1968 INVENT )R ww m ,6 Phillip W4 S N r J m r r m A 0 TS S 0 n 0 D United States Patent 3,457,991 WELL TOOLS Phillip S. Sizer, 14127 Tanglewood Drive, Dallas, Tex. 75234, and Donald F. Taylor, Jr., 3555 Vancouver, Dallas, Tex. 75229 Filed Feb. 16, 1968, Ser. No. 706,034 Int. Cl. E21b 33/06, 33/122 US. Cl. 166--.5 3 Claims ABSTRACT OF THE DISCLOSURE A well flow control assembly which includes a plurality of flowout preventers and an automatic subsurface safety valve positioned in the blowout preventers. The valve is biased to closed position and is moved to open position by pressure fluid which is controlled by means positioned at the surface of the well.

This invention relates to well tools and more particularly to a flow control assembly for a well installation.

One object of this invention is to provide a new and improved flow control assembly, which is installable in the well during the drilling of the well, through which various operations may be performed, such as perforating, short time production testing, and the like; which is held in place in the well installation by blowout preventers of the well installation used in the drilling of the well; which is provided with a valve located below the blowout preventers and which may be controlled from the surface for controlling flow from the well.

Another object is to provide a flow control assembly in which the valve is biased toward its closed position for automatic closing and which is movable to open position by pressure fluid means controllable from the surface; which is provided with a full bore opening therethrough to permit movement of well tools therethrough into and from the well; and which may be readily closed to prevent undesired uncontroled flow from the well.

Another object is to provide a well flow control assembly usable in a well installation employed in the drilling of a well below a body of water wherein the valve of the flow control assembly is positioned beneath or near the ocean floor, and wherein the control valve assembly is positioned in the well and held by blowout preventers which closes the annular passage about the well flow control assembly; and, wherein the annulus between the casing and the drill pipe or tubing string in which the valve assembly is connected is closed off by the blowout preventers, and the bleed lines, or kill lines, between the blowout preventers provide a passage therebetween for conducting control fluid from the surface to the valve to control the opening and closing of the valve; and wherein the blowout preventers hold the flow control assembly against movement from the well installation.

An important object of the invention is to provide a valve having a housing in which a pair of balls provided with axial passages are mounted, each of which is separately biased toward its closed position and has an operator means for moving it to open position, the housing having means for simultaneously conducting control fluid under pressure to the two operator means to cause the balls to be moved to their open positions; and, wherein the valve housing is provided with a flow passage through which control fluid under pressure is transmitted to the operator means to move the ball to its open position against the force exerted thereon by the means biasing the piston member.

A further object is to provide a new and improved means for locating the control valve assembly with rem 3,457,991 Ice Patented July 29, 196

spect to the blowout preventers and the control fluid conduit of the valve properly disposed for introduction of control fluid pressure thereto.

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 is a schematic illustration of a well installation with a flow control assembly embodying the invention disposed therein;

FIGURES 2 and 3 are an enlarged schematic illustration showing the flow control assembly in position between the blowout preventers in the well installation;

FIGURE 4 is a vertical, partly sectional view of the upper portion of the valve of the flow conductor assembly;

FIGURE 5 is a View similar to FIGURE 4, being a continuation thereof showing an intermediate portion of the valve;

FIGURE 6 is a view similar to FIGURE 5, being a continuation thereof, showing the bottom portion of the valve;

FIGURE 7 is a fragmentary enlarged view of a portion of the upper portion of the valve shown in FIGURE 4; and

FIGURE 8 is an enlarged fragmentary sectional view of another portion of the upper portion of the valve shown in FIGURE 4.

Referring now to FIGURE 1 of the drawings, the well installation 30 at the bottom of a body of water, which is used during the drilling of the well, includes a casing 31 secured in the usual manner to a casing head 32, a stack of blowout preventers 33 mounted on the casing head, a latch head 35 mounted on the uppermost blowout preventer and a riser tube 36 releasably connected to the upper end of the latch head and extending above the surface of the water and through an aperture in a work platform 37, which may be a floating platform or a pile supported or a fixed platform. This well installation provides a longitudinal continuous passage 38 from above the surface of the water to the well through which a flow conductor 39 having a flow control assembly 40 connected therein may extend and be supported adjacentv the bottom of the body of water by means of one or more of the blowout preventers 33. The blowout preventers may be of any well known and suitable type, and be manually operable by divers or may be remotely operated, as for example, hydraulically, in which event suitable control fluid lines would extend therefrom to the work platform. Such blowout preventers have means for holding the flow conductor 39 which extends therethrough against longitudinal movement and for sealing therearound. The usual bleeder or kill flow lines or conductors 41 are connected to the well installation and provide for flow communication between the bore of the casing between adjacent pairs of the blowout preventers and pumps, flow lines or other apparatus at the work platform for loading or cleaning the well bore or circulating fluids into or out of the well bore in the usual manner.

The flow conductor assembly includes a string of tubing or drill pipe 44 which extends to any desired depth in the well and which usually has a packer (not shown) for closing the annulus between the tubing and the casing above a producing formation, and a valve 45 which controls flow of fluids through the string of tubing or drill pipe. The flow control assembly also includes a surface flow conductor 49 connected to the upper end of the valve. The flow conductor 49 is employed to properly locate the valve 45 relative to the blowout preventers.

In use, after the drilling operations have been completed and while the drilling well installation 30 is still in place, if it is desired to perform short time production testing operations on the well the valve 45 may be connected to the upper end of the drill pipe; or if the well has been completed and the flow string of tubing is lowered in the well the valve 45 is connected to the upper end of the string of tubing, and the surface flow conductor 49 is connected to the upper end of the valve, whereby the drill pipe or tubing string and valve are lowered into place through the passage 38 into the well.

When the string of tubing or drill pipe and the flow control assembly 40 are in the desired location in the well, at least one of the upper blowout preventers is operated to engage a tubular support connector 46 at the upper end of the valve to hold it against upward or downward movement in the well installation 30 and also to seal therebetween. Suitable surface control equipment 60 is connected to the upper end of the surface flow conductor 49 to control the flow therethrough from the string of tubing 44 and to permit introduction of well tools into the tubing through the surface conductor 49.

Control fluid under pressure is supplied to the valve 45 from a suitable control manifold 61 through one or more of the kill lines 41 to control operation of the valve. Such operation of the valve may require that one or more of the blowout preventers 33 below the upper one engaged with the support connector 46 be closed to direct control fluid passage to the valve, as will be hereinafter more fully explained. Tools may be run through the flow control assembly and the tubing string to perforate the easing at the location of the producing formation and, if desired, cementing or other well operations, and the like, may also be performed by use of the flow control assembly and the tubing string. The valve 45 is closed and opened as required by such operations.

The production of well fluids from the earth formation may be tested by permitting their flow upwardly through the string of tubing to the surface. The valve 45 may be closed at any desired time by decreasing the fluid pressure which is transmitted thereto from the manifold 61.

If it is necessary to remove the conductor 49 and the riser pipe 36 from the latch head, as due to the occurrence of store conditions at the location of the well, the control fluid pressure in the kill line is released, and kill lines disconnected from the platform, whereupon the valve 45 is automatically closed, and the surface conductor 49 then detached from the connector head as by unscrewing it. The riser pipe 36 may also be detached from the latch head. The working platform itself, if floating, either be left anchored in place or removed prior to the arrival of the storm. The string of tubing 44, the valve 45, and the support connector 46 are now left supported in the well by the blowout preventers. Since the water conditions at the bottom of the body of water are always relatively quiet with little or no wave action, there is little likelihood that the portions of the flow conductor assembly left in the well will be damaged. The valve 45, which is below the blowout preventers, closes the upper end of the tubing and the blowout preventers close off the annulus between the tubing and the casing, so that the well is shut in. Also, in the event the riser pipe and the flow conductor 49 are damaged or broken away from the support connector and latch head, as in the event the work platform is struck by a vessel or a sudden storm or unpredicted earthquake wave occurs, the valve 45 may be closed by operation of the control fluid manifold 61 controlling the pressure in the kill line 41; or, if the kill line is damaged or broken the valve will automatically close. The assembly from the blowout preventers downwardly will in all likelihood not be broken away when the riser pipe, the flow conductor 49 or the kill lines 41 are so detached or broken away from it.

When the storm ceases or if for any other reason it is desired to come back and reconnect the flow conductor 49 to the connector head in order to perform further or additional operations on the well, the floating working platform 37 is again positioned over the well head assembly, the riser pipe 36 is connected to the latch head 35 and preferably any water within the well head assembly above the blowout preventers neck is removed, as by pumping or circulating it out. The flow conductor 49 is lowered through the riser pipe and connected to the support connector 46, and the kill or bleeder line 41 is again connected to the control fluid manifold 61. If kill lines 41 are reconnected immediately after reconnecting the riser pipe 36, displacing the sea water from the riser pipe can be done with ease by circulation through the kill lines. Further operations then may be performed through the flow control assembly and the string of tubing, such as further production testing, cementing and the like.

The valve 45 includes an elongate tubular mandrel which includes a top section 101 provided with internally threaded section 103 into which the lower end of the support connector 46 is threaded, and an internally threaded section 102 in which the lower end of an outer flow conductor may be threaded, if desired. The top mandrel section is provided with one or more vertical upwardly opening longitudinal passages 105 each having a threaded socket 98 at its upper end, shown closed by a threaded plug 99 having seal means thereon sealing b..- tween the plug and the bore wall of the passage. A plurality of lateral ports 105:! are provided in the top mandrel section each communicating at its inner end with one of the vertical passages 105, and each of these lateral ports also has a threaded socket 98a at its outer end which may be plugged by a plug 99, if desired. In the form and installation illustrated, however, the lateral ports remain open to communicate with the annulus between the valve and the casing and between the upper and lower blowout preventers to provide for entry of control fluid into the passages 105. The lower end of the passages 105 opens through a transverse bore 106 to an annular passage 107 between the mandrel and a sleeve 109 whose upper end portion is threaded on the intermediate portion of the reduced lower end section 110 of the top mandrel. The upper end of the passage 107 is closed by a seal assembly 112 which may include an O-ring 113 which engages the external surface 114 of the top mandrel section below a downwardly facing annular shoulder 115 thereof and the internal surface 117 of the sleeve 109 above an upwardly facing shoulder 118 thereof. The seal assembly also includes a back-up ring 119 whose downward movement is limited by its engagement by the shoulder 118, a pair of back-up

rings

121 and 122, and a thrust ring 123 whose upward movement is limited by its engagement with the shoulder 115. The lower end of the annular passage is similarly closed by a seal assembly 125 whose O-ring 126 engages the external surface 127 of the mandrel and the internal surface 128 of the sleeve below its internal annular shoulder 129. The seal assembly includes an upper back-up ring 131 whose upward movement is limited by its engagement with the sleeve shoulder 129, a pair of back-up

rings

132 and 133, and a thrust ring 134 whose downward movement is limited by its engagement with the upwardly facing end surface or shoulder 135 of the seal assembly retainer member 1312 threaded in the lower end of the sleeve.

The mandrel 100 includes an upper cylinder section 137 whose upper end is threaded on the reduced lower end portion of the top mandrel section 101, a connector section 138 whose upper portion is threaded into the lower portion of the upper cylinder section 137, an upper operator section 139 whose upper portion is threaded on the lower reduced portion of the connector section 138, a connector section 140 whose upper portion is threadedly secured into the lower end of the upper operator section 139, a lower cylinder section 141 whose upper end is threaded on the connector section 140, a connector section 142 whose upper end telescopes into the lower cylinder section 141 and is threadedly secured thereto, a lower operator section 143 whose upper end is threaded on the reduced lower end portion of the connector section 142, and a bottom section 144 which extends into the lower end portion of the lower operator section and is threadedly connected therein. Each of the mandrel sections may be held against rotation relative to the other adjacent sections to which it is connected by means of set screw 145 which extends through end slots of one section into a threaded bore of the other. The

connector mandrel sections

138, 140, 142 andthe bottom section 144 have seal assemblies, which may include an O-ring 148 and a back up ring 149 positioned in external recesses thereof which seal between the connector sections and the mandrel sections into which they telescope.

The ball valve 150 is pivotally mounted in the lower operator mandrel section 139 by means of pins 151 whose outer portions are rigidly secured in suitable lateral bores 152 of the mandrel section 139 and whose inner portions extend into slots 153 of the ball. The engagement of the pivot pins 151 with the surfaces of the ball defining the slots which extend angularly relative to the central axis of the ball causes the ball to rotate substantially 90 degrees from its open position wherein its axial passage 155 extends longitudinally relative to the mandrel and a closed position wherein its passage 155 extends transversely relative to the longitudinal axis of the mandrel when the ball valve is moved upwardly a predetermined distance in the housing. The valve is moved between its lower open position and its upper closed position by an operator assembly 160 which includes a piston 161, a tubular piston member 162 whose upper end is connected to the piston, a tubular housing 163, upper and lower

annular seats

164 and 165 disposed above and below the ball, and a pair of cooperative upper and lower locking rings 166 and 167 which hold the ball and the seats against displacement from the housing.

The tubular piston 161 includes a tubular upper extension 171 which extends upwardly into the top mandrel section 101 and on which are mounted upper and lower seal assemblies 175 which seal between external surfaces 173 of the upper extension and the internal surface 174 of the top mandrel section. Each of the assemblies may include a plurality of pressure sensitive type packing rings for sealing in both upward and downward directions as shown. Downward movement of the upper seal assembly 175 is limited by the upwardly facing end shoulder 176 of a retainer ring 177 whose downward movement is limited by engagement of its internal downwardly facing annular shoulder 178 with top surfaces of a plurality of ring segments 182 whose inner portions extend into an annular recess 183 of the piston extension. Upward movement of the upper seal assembly 175 is limited by the bottom annular shoulder 186 of a packing retainer ring 185. The retainer ring 185 may be secured to the top end of the packing extension in any suitable manner, as by means of pins 187 which extend through suitable lateral bores of the retainer ring into the lateral bores of the piston extension. Upward movement of the lower packing assembly on the piston extension is prevented by a back up ring 179 whose top annular surface engages the downwardly facing annular surfaces of ring segments 182 which extend outwardly beyond the limits of recess 183. Downward movement of the lower packing assembly on the piston extension 171 is limited by the upwardly facing shoulder 180 of the piston extension 171.

The lower end of piston 161 has upper and lower packing or seal assemblies 191 and 192 mounted thereon above and below its external annular flange 193. The seal assembly 191 may include a plurality of packing rings 194i, a back up ring 195 which engages the top annular shoulder 196 of the flange 193 to limit downward movement of the packing rings, and a retainer ring 198 which limits upward movement of the packer rings. The retainer ring is secured to the piston by suitable pins 199 which extend through lateral apertures of the retainer ring into lateral bores of the piston. The lower seal assembly 192 similarly may include a plurality of packer rings 201 whose back up ring 202 engages the downwardly facing annular shoulder 203 of the piston flange 193 to limit upward movement of the packer rings on the piston. Downward movement of the packer rings is limited by a retainer ring 205 secured to the piston by screw pins 207 which extend through suitable lateral apertures of the retainer ring into lateral bores of the piston.

The upper end of the tubular piston member 162 telescopes into the enlarged lower portion of the bore of the piston and its upward movement into the piston is limited by the engagement of its annular external shoulder 211 with the downwardly facing internal shoulder 212 of the piston. The piston member is held releasably against downward movement relative to the piston by a split snap ring 214 whose inner portions extend into an external annular recess 215 of the tubular member and whose outer portions extend into the internal annular recess 216 of the piston.

The snap ring has an upwardly and outwardly inclined outer cam surface 217 whose engagement with the annular shoulder 217a of the piston defining the lower end of the recess 216 when the piston member is forced downwardly relative to the piston causes the snap ring to contract and move inwardly into the recess 215 of the piston member and thus release the piston member for downward movement relative to the piston. The snap ring also has an upper external downwardly and outwardly inclined shoulder 217b whose camming engagement with the bottom end surface of the piston 161, as the piston member is telescoped upwardly into the piston, causes the snap ring to be moved resiliently inwardly into the recess 215 of the piston member. The snap ring moves resiliently outwardly into the piston recess 216 when it moves into alignment therewith.

The piston and the mandrel define an annular piston chamber 218 above the piston and below the bottom annular end surface 219 of the top mandrel section. The annular passage 107 communicates with the piston chamber 218 through one or more lateral ports 220 of the upper piston mandrel section 137.

The piston is biased upwardly by a. pair of

springs

221 and 222 disposed about the piston member in an annular spring chamber 223 between the piston member and the piston mandrel section 137. The upper end portions of the spring abut the downwardly facing

annular shoulders

224 and 225 respectively, of a spring retainer ring 227 rigidly secured to the piston member by a plurality of screws 228 threaded in the lateral bores 229 of the spring retainer whose pin end portions 230 extend into the apertures 231 of the tubular member. The lower ends of the springs engage the top annular shoulder 232 of the connector mandrel section 138.

Fluid may flow into and out of the spring chamber as the piston moves upwardly and downwardly in the mandrel through a plurality of ports 233 of the piston member.

The connector mandrel section 138 is provided with an internal annular downwardly opening recess 235 in which is disposed a seal assembly 236 which seals between the connector mandrel section and the tubular piston member below the ports 233 thereof. Upward movement of the seal assembly, which may include a plurality of packing rings 237 is limited by the downwardly facing annular shoulder 238 of the connector mandrel section and down ward movement thereof is limited by an annular seal retainer ring 240 threaded in the lower enlarged end portion of the connector section. An O-ring 241 seals between the retainer nut and the connector mandrel section. The seal assembly 236 prevents upward flow of fluids into the spring passage and then inwardly into the tubular piston member when the ball is in closed position.

The housing 163 has an upper annular portion 245 which is telescoped on the reduced lower portion 246 of the tubular piston 162 and is rigidly secured thereto in seal tight relationship in any suitable manner, as by a weld 247. The upper annular seat 164 is disposed in the downwardly facing annular recess 250 of the housing and its upward movement in the housing is limited by the engagement of its top shoulder with an internal downwardly facing shoulder 252 of the housing. An O-ring 253 disposed in an upper external recess of the seat seals between the upper seat and the housing. The upper seat may have an annular seat ring 255 of a suitable hard surfaced low friction substance, such as is commercially available under the names Hostaloy and Colmonoy, interposed between its internal annular arcuate surface 256 and the outer spherical surface of the ball 150. The seat ring may be bonded or otherwise suitably secured to the seat.

The housing has a plurality of dependent resilient collet fingers 260 which extend below the ball 150 and are provided with internal bosses 261 at their lower ends whose lower portions are received in an internal annular upwardly facing recess 262 provided by the lock rings 166 and 167. Outward movement of the lower ends of the collet fingers is limited by the engagement of the external surfaces of the bosses 261 with the internal annular shoulder 263 of the upwardly extending annular lock flange 266 of the lower locking ring 167, Upward movement of the collet fingers relative to the upper lock ring is limited by the engagement of the upper shoulders 267 of their internal bosses with the downwardly facing annular shoulder 268 provided by the external annular flange 269 of the upper lock ring.

The two lock rings are secured to one another by a plurality of socket head cap screws 270 which extend upwardly through suitable apertures in the lower lock ring into the downwardly opening threaded bores 271 of the upper lock ring. Lock washers 272 are interposed between the heads of the cap screws and the downwardly facing shoulders 274 provided by the downwardly opening bores 275 of the lower lock ring in which the heads of the cap screws are recieved.

Downward movement of the lower seat 165 is limited by the engagement of its bottom surfaces 278 with the top surface 279 of the upper lock ring 166. The lower seat has an internal upwardly facing annular arcuate surface 280 to which is bonded or otherwise suitably secured a seat ring 281 of a suitable low friction material which engages the spherical outer surface of the ball 150. The lower seat 165 is biased upwardly toward engagement with the ball by a plurality of springs 284 disposed in a plurality of downwardly opening circumferentially spaced bores 285 of the lower seat. The upper ends of the springs engage the downwardly facing surface 286 defining the upper end of the bore and their lower end portions engage the top surface 279 of the upper lock rings. The upper and lower lock rings have pins 288 whose inner portions are secured in suitable lateral bores of the lock rings and whose outer portions extend outwardly into the longitudinal slots 289 between the collet fingers to engage the collet fingers and prevent rotation of the lock rings relative to the housing 163. The pivot pins 151 also extend into the recesses of the ball through two of the longitudinal slots 289. It will be apparent that the upper and lower seats, the ball and the upper lock ring 166 may be inserted upwardly into the housing 163 between the collet fingers whose lower end portions flex resiliently outwardly to permit such upward movement of these components and then flex inwardly as the top internal shoulders 267 of their bosses 261 move below the lower shoulder 268 of the upper lock ring flange 269. The lower lock ring is then moved upwardly to telescope its lock flange 263 about the lower end portions of the collet finger bosses and is then secured to the upper lock ring by the cap screws 270 thus locking the collet fingers against outward movement.

Downward movement of the piston member 162 and the housing is limited by the engagement of the downwardly facing shoulder 289 of the lower lock ring 167 with the internal upwardly facing shoulder 290 of the connector mandrel section 140.

The lower ball 150a and its operatively and structurally associated elements are similar in structure and mode of operation to the ball 150 and its operatively and structurally associated elements and, accordingly, the elements associated with the lower ball have been provided with the same reference numerals, to which the subscript a has been added, as the corresponding elements operatively associated with the upper ball 150. Fluid may flow between the passage 107 and the piston chamber 218a above the piston 161a via the port 220a of the lower piston mandrel section 141. Downward movement of the piston 16211 is limited by the engagement of the shoulder 289a of the lower lock ring with the shoulder 293 of the bottom mandrel section 144. The upward force exerted on the piston 162 by the

springs

231 and 222 and the upward force exerted on the piston 162a by the spring 221a and 222a are greater than the static pressure of the fluids in the conductor 46 and in the passage 48 between the conductors 46 and 47 so that the pistons will move upwardly and rotate the balls to their closed positions when the fluid in the small surface flow conductor is not maintained under pressure.

When it is desired to open the two ball valves, the fluid pressure in the passage 107 is increased, as by pumping from control manifold 61, through the kill line 41 to the ports or 105:: of the valve 45 and when the downward force exerted on the pistons 161 and 161a by the fluid pressure in the piston chambers 218 and 218a exceeds the total upward force exterted on the pistons by the

springs

221, 222, and 221a, 222a, any upwardly acting pressure differentials across the balls and their pistons, and any frictional resistance present in the system due to these forces, the pistons will start to move downwardly. Continued pumping from manifold 61 will cause the pistons to continue to move downwardly until stopped by the engagement of the shoulders 289 and 289a of the lower lock rings 167 and 167a with the respective upwardly facing shoulders 290 and 290a of mandrel sections and 144. Continued pumping from the manifold 61 will produce an immediate pressure increase in the fluids being pumped which may be seen on a pressure gauge in the manifold system on the surface. The pressure required at the pistons 161 and 161a is approximately ten (10) percent greater than well pressure acting to close the ball valves. During the downward movement of pistons witthin their limits of travel, the balls and 150a rotate through substantially 90 degrees from a closed position wherein their axial passages and 155a are out of alignment with the axial passages of the housing, the tubular piston members, the pistons, and the mandrel to positions wherein they are in alignment with these axial passages to permit fluid flow through the valve, and the passage of well tools therethrough.

If the pressure in the passage 107 is decreased below the value at which its force holds the pistons in their lower open positions, the force of the springs and of any upwardly acting pressure differential acting across the pistons and balls, moves the pistons and the balls upwardly in the mandrel thus causing the balls to rotate through substantially 90 degrees to positions wherein their axial passages 155 and 155a extend transversely relative to the longitudinal axis of the mandrel and the engagement of their outer surfaces with the seat members 255 and 255a then prevents upward flow of fluid through the mandrel.

Upward movement of the

pistons

161 and 162 is limited by the engagement of the shoulders 294 and 294a of the housings 163 and 163a with the shoulders 295 and 295a of the packer nuts 240 and 24011, respectively. Any upward pressure differential existing across the balls now tends to hold them in sealing engagement with the seat members. During the upward and downward movement of the balls, the lower and

upper seats

164 and 164a and 166 166a of the two balls guide the rotational movement of the ball valves.

The balls when they are in their closed positions may be moved to open positions either by increasing the pressure within the annular passage 107 in the manner described above or by increasing the pressure within the flow conductor 49, as by pumping thereinto at the surface and therefore in the passage 160a above the upper ball 150. When the pressure within the passage 160a is increased to such value and its force acting across the upper ball 150 and the upper piston 161 exceeds the force of the upwardly acting pressure diflerential existing across the ball 150, the force of

springs

221 and 222 and the force of the snap ring 214, the ball valve is moved downwardly and pulls the piston member 162 downwardly therewith, the camming engagement of the external lower cam shoulder 217 of the snap ring with the bottom shoulder 217a of the piston camming the snap ring inwardly into the recess 215 to permit such downward movement of the piston member relative to the piston. The piston is held against downward movement since the pressure in the chamber 218 is now considerably smaller than the pressure below the piston. As more fluid is pumped into flow conductor 49, the ball 150 is moved downwardly and at the same time is rotated to at least partially open position admitting fluid pressure to the passage 160a above the lower ball 150a. The ball 150a and the piston member 162a are then moved downwardly relative to the piston 161a and the ball 150a rotates to at least partially open position. Once the two balls are in at least partially open positions, fluids may be pumped downwardly through the valve and into the tubing 44 which is connected to the lower end of the bottom mandrel section 144. When the pumping is stopped and the pressure across the ball valves tends to equalize, the springs 221a and 220a move the piston 161a and the ball 150a upwardly and the

springs

221 and 222 move the piston 161 and the ball 150 upwardly back to their upper closed positions, and the snap ring 214 enters the recess 216 to relatch the piston 161a to the connector section 140 and the upper operator section.

In use, the tubular support connector 46 may be of sufficient length, as shown in FIGURE 1, to dispose the valve 45 some distance below the surface of the earth in the well bore. Or, if desired, the support connector may be sufliciently short to dispose the valve in position to be engaged by one of the stack of blowout preventers 33, as shown in FIGURES 2 and 3. In either case, the upper blowout preventer 33a has its clamping and sealing rams 503 engaged in an external annular groove 500 formed in the exterior of the support connectors, so that the ram seals off the annular space between the exterior of the connector and the interior wall of the blowout preventer. The shoulders 504 and 505 at the upper and lower ends of the recess are engageable with the rams 503 to prevent undesired longitudinal movement of the support connector, the valve 45 and the tubing spring 44 therebelow, whereby they may be suspended in the well bore supported by the blowout preventer.

As shown in FIGURES 2 and 3, lowermost blowout preventer 330 has its clamping and sealing rams 5030 disposed in sealing engagement with the exterior of the sleeve 109 at the upper end of the valve 45, below the lateral ports 105a in the top mandrel section 101 at the upper end of the valve, and seal ofl the annular space between the exterior of the valve and the interior wall of the blowout preventer 33c.

An annular pressure chamber 506 is thus formed between the upper blowout preventer 33a and lower blowout preventer 33c exteriorly of the valve and the support connector 46, into which control fluid may be introduced through one or more of the kill or bleeder lines 41 which are connected in the usual manner to the lateral openings 507 in the wall of the blowout preventers. The kill or bleeder lines have valves 508 connected therein adjacent the blowout preventers, and the lines extend upwardly, as shown in FIGURE 1, to the work platform 37, where they are connected to the control manifold 61.

The support connector 46 has a head member or bushing 520 to which an inner tubular conductor 521 is connected, as by threads, and an outer tubular sleeve 522 surrounding in spaced relation the inner conductor and also connected, as by threads, to the head member or bushing. The lower end of the inner conductor 521 is connected to the threaded bore 103 of the top mandrel section 101 of the valve 45, and the outer tubular sleeve 522 is connected at its lower end to the threaded bore 102 in said top mandrel section, as shown in FIGURE 4. An annular flow passage 523 is formed between the inner conductor and the outer sleeve extending from the head member 520 of thhe support connector to the top mandrel section 101 of the valve, where it communicates with the vertical ports 105 of the top section. One or more lateral ports 525 are formed in the bushing 520 to provide communication between the annular flow passage 523 in the connector and the exterior thereof. As shown in FIGURE 2, these lateral ports 525 are each closed by a plug 526 threaded into the port and having a seal thereon for sealing with the bushing, but the ports may be left open in such an installation, if desired, to admit control fluid to the annular flow passage. In such event, the plugs 99 would be removed from the vertical ports 105 in the top mandrel section 101 to permit the control fluid to pass through the ports to the passage 107 of the valve. Since the lowermost blowout preventer seals around the valve below the lateral ports 105a, the control fluid may also enter the ports 105 and pass into the annular passage 107 of the valve to act thereon.

If, however, the valve 45 is disposed as shown in FIG- URE 1, the intermediate blowout preventer 33b or the lowermost blowout preventer 330 may be closed about the exterior of the support connector sleeve 522 to seal between the sleeve and the blowout preventer below the lateral ports 525 in the head member or bushing 520 to form an annular pressure chamber 506 between the upper and lower blowout preventers exteriorly of the upper portion of the support connector with the lateral ports 525 in the head member or bushing 520 communicating with said pressure chamber and the annular flow passage 523 to permit control fluid pressure to pass from the pressure chamber through the flow passage 523 into the valve to control opening and closing of said valve. The kill or bleed line 41a between the upper blowout preventer and the intermediate blowout preventer may be used to conduct the control fluid from the manifold 61 to the valve. In this type of installation, the lateral ports 105a in the top mandrel section 101 of the valve would be closed by the plugs 526a installed in the threaded opening 98a, while the vertical ports 105 are opened.

With either type of installation, any desired well operation may be performed, the valve 45 being opened and closed as desired by controlling the control fluid pressure transmitted to the valve through the kill lines 41, the annular pressure chamber 506 and 506a and the ports in the support connector on the valve top mandrel section 101. Obviously, various well tools may be lowered through the flow control assembly, including the valve, into the tubing or drill string 44 therebelow. Also, fluids may be circulated into and out of the well by Way of the kill or bleeder lines 41, the annular space between the tubing or drill spring and the casing, the bore of the tubing or drill string, the valve assembly, the surface flow conductor 49 and the surface control equipment 60. Also, the well may be quickly and completely shut in by releasing the control fluid pressure in the kill or bleeder line 41 communicating with the annular pressure chamber 506 or 506a and the ports of the valve.

Of course, if the well is provided with a packer at the lower end of the tubing string 44, only the upper blowout preventer need be closed, since the annular chamber between the packer and the upper blowout preventer would form the pressure chamber 506b, and control flow pressure may be introduced into that chamber to act through the lateral ports 105a and 525 on the valve at any point in the annular space between the packer and the upper blowout preventer. However, it is preferable that the valve be located near the upper portion of such annular chamber in order that the hydraulic fluid pressure head of the column of control fluid in the annular pressure chamber will not be so great as to prevent the valve from being closed automatically by the spring when the pressure in the bleed lines or kill lines is relieved. Obviously, this arrangement would require only that the upper blowout preventer be closed about the support connector above the lateral ports opening into the valve.

Also, if desired, the structure just described might be utilized to leave a column of loading fluid or mud acting on the packer between the tubing or drill pipe and the casing, and by circulating liquid or washing fluid through the lower kill line or bleed line 410 and out through the upper bleed line or kill line 41a to remove the loading fluid or mud from that portion of the annular space, permit the use of gas or a lighter liquid control fluid pressure in such upper portion of the annular space to control actuation of the valve. This would result in maintaining the loading fluid pressure on the packer but permit the use of the valve with a control fluid providing a relatively light hydrostatic head, so that the spring which closes the valve need not be strong.

Also, it is believed readily apparent that, while a particular valve 45 has been illustrated and described, valves having other structure may be used in the installation; for example, a valve of the type shown in the patent to John V. Fredd, Reissue No. 25,471, dated Nov. 5, 1963, might be used by providing the lateral ports opening to the annulus.

It will be readily apparent that in each of the installations described, the valve is positioned at a location near the bottom of the body of water so that if any damage occurs to the installation above the well, or if the kill or bleeder lines 41 are damaged or broken to release the pressure therein, the valve will automatically close, fail safe, to prevent flow of well fluids through the string of drill pipe or tubing.

It will now be apparent that a new and improved flow control apparatus has been illustrated and described for performing various operations in a well which utilizes the blowout preventers of the equipment which was used during the drilling of the well to support a string of drill pipe or tubing and a valve which controls the flow of fluids through such string.

It will further be seen that the apparatus includes flow conductor means which comprises the customary kill or bleeder line flow conductors to provide a passage for the flow of control fluid to and from the valve and that no extra, special flow conductor is required for the system.

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 flow control assembly for a well having a casing disposed in the well bore and a plurality of blowout preventers at the upper end of said casing, including; a normally closed valve having a flow passage therethrough; said valve having means associated therewith disposed to be engaged by one or more of the blowout preventers at the upper end of the well whereby said valve is held against movement out of said well and an. annular space between the well casing and the valve is sealed off by said blowout preventers; means for conducting a control fluid pressure to the valve through the annular space between the valve and the blowout preventer; conduit means in the valve for admitting control fluid from the annular space between the valve and the blowout preventer to the valve to act on the valve to move the same to open position, said valve being returnable to closed position upon release of pressure.

2. A well flow control assembly for use in a well having a well casing disposed in the'bore of the well provided with a plurality of blowout preventers at the upper end of the casing, and including: a flow conductor and having a flow passage therethrough communicating with the flow passage of the conductor; means on said flow conductor engaged by the blowout preventers for sealing therebetween and for holding the conductor against longitudinal movement in the casing; a second blowout preventer engaged with one of said valve and said conductor to provide an annular pressure chamber between said first blowout preventer and said second blowout preventer for control fluid pressure; a lateral bleed line communicating the annular pressure chamber with a control assembly at the surface of the well for conducting control fluid pressure to said pressure chamber; and flow conduit means in said valve opening to the annular pressure chamber for receiving control fluid pressure from said annular pressure chamber to said valve acting on the valve to open and close the same.

3. A well flow control system for a well having a well casing disposed in the well bore and provided with a plurality of vertically spaced blowout preventers at the upper end of the casing, and having a bleeder line communicating with the bore of the well casing between each of the blowout preventers and below the lower blowout preventer, said flow control assembly including; a flow conductor string disposed in the casing and communicating with the well bore and with the surface of the well above the blowout preventers; a normally closed valve disposed in said flow conductor string and having fluid pressure responsive actuating means for moving said valve between closed and open positions; means in said valve communicating the fluid pressure responsive means of the valve with the exterior of the valve and the flow conductor string; means engageable by one of said blowout preventers to support the flow conductor string and the valve against longitudinal movement in the well casing in sealed relationship therewith; control means at the surface of the well having communication with the lateral bleed lines of the well for conducting control fluid pressure through said lateral bleed lines to the well bore below the blowout preventer closed about the flow conductor to act on the pressure responsive operating means of the valve to open the valve, said pressure being releasable to permit the valve to return to the normally closed position.

References Cited UNITED STATES PATENTS 3,007,669 11/1961 Fredd l66-72X 3,065,793 11/1962 Page 166-72 JAMES A. LEPPINK, Primary Examiner US. Cl. X.R. 16672, 224

UNITED STATES PATENT OFFICE 56g CERTIFICATE OF CORRECTION Patent No. 3,457.991 Dated July 29, 1969 Ihventofls) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

col. 1, line 2, for "flowout" read --b1owout-- col. 8, line 51, for "witthin" read --within-- col. 9, line 60, for "spring" read --string-- SIGNED ANU QSEAL) Anesu Edward MG Fla-whoa In, mm E. 80 m ti g Officer commissioner of Patents