annular safety valve free sample
This application claims the benefit of U.S. Provisional Application No. 62/773640, filed on Nov. 30, 2018, entitled Annular Safety Valve with Groove Around Port, the contents of which is hereby incorporated in its entirety by this reference.
The present disclosure relates generally to an annular safety valve (ASV) that can be positioned downhole within a wellbore, and more particularly (although not necessarily exclusively), to an ASV that includes a groove positioned around a port or an opening of the ASV.
Certain aspects and features of the present disclosure relate to an ASV that can be positioned in the wellbore. The ASV may be a part of a completion string that is positionable downhole in a wellbore. The ASV can actuate between an open and a closed position. The ASV can include a housing having one or more openings for gas injection. The ASV can further include a poppet positioned within the opening. A surface region of the poppet can close or seal against a seat of the opening in the closed position. The ASV can be actuated to the closed position in response to an emergency situation to shut in injected gas pressure in the annulus of the wellbore for safety reasons. In the closed position, the ASV traps the injection gas pressure in the annulus below the ASV. In the open position, the poppet may not close or seal the opening such that under normal gas injection conditions, the ASV allows gas injection via the annulus to move past the ASV. The position of the poppets of the ASV can be controlled via an actuator within the ASV that may move the poppet (or a set of poppets) off a seat (i.e. move the poppet sealing-face off the seat of the housing) surrounding the opening to position the ASV in the open position. The actuator may be coupled to a control line. The actuator may also move the poppet (or a set of poppets) onto the seat to position the ASV in the closed position. To close the ASV, the control line pressure can be bled off and pressure from a spring can push the poppet(s) (i.e. the poppet sealing-face) back onto the seat, moving the ASV to the closed position and trapping annulus pressure below the ASV. With the ASV in the closed position and pressure trapped below the poppets, the housing can subjected to tubing pressure and axial loading on the poppets.
FIG. 1 is a schematic illustration of a well system 10 having a wellbore assembly according to one aspect of the present disclosure. The well system 10 includes a borehole that is a wellbore 12 extending through a surface 14 and various earth strata. The well system 10 may be a land based well system or a sea based well system. A casing string 13 may be positioned within the wellbore 12, and a tubing string 15 may be positioned within the casing string 13. The tubing string 15 may be for example a completion string. The tubing string 15 may include an ASV 16. The ASV 16 may provide a communication path in an annular area between the tubing string 15 and the casing string 13. The ASV 16 may have an open position to allow pressure to transmit between a first annular area 18 of the wellbore 12 (e.g. annular area between the casing string 13 and the tubing string 15) below the ASV 16 and a second annular area 20 of the wellbore (e.g. annular area between the casing string 13 and the tubing string 15) above the ASV 16. The ASV 16 may have a closed position to prevent pressure to transmit between the first annular area 18 of the wellbore 12 below the ASV 16 and the second annular area 20 of the wellbore 12 above the ASV 16.
As described above with respect to FIG. 2, the grooves 112, 124 can separate a portion of the seats 110, 122 from the other portions of the housing 200. The separation between the seat 110, 122and other portions of the housing 105 can allow the housing 105 to deform into the groove 112, 124 in response to pressure, without affecting the shape or size of the openings 104, 120, or the seats 110, 122. For example, the grooves 112, 124 can isolate a sealing face of the seats 110, 122that contacts and seals against a poppet (not shown) from the influence of the remainder of the housing 105 expanding due to internal tubing pressure or annular pressure below the ASV 100. Thus, the grooves 112, 124 can provide a certain amount of flexibility to the respective seats 110, 122 and allow the portions of the respective seats 110, 122 that seal against the poppets to retain their shapes. The sealing between the poppets and the respective seats 110, 122 can be improved and gas leakage between the poppets and the respective seats 110, 122 when the ASV 100 is in a closed position can be reduced by providing the grooves 112, 124.
Example 1 is an annular safety valve positionable in a wellbore, the annular safety valve comprising: a housing having an opening extending through the housing to allow to allow pressure to transmit between a first annular area of the wellbore below the annular safety valve and a second annular area of the wellbore above the annular safety valve, wherein the housing defines the opening by a seat face; a poppet extending through the opening; and a groove at least partially surrounding the seat face for maintaining a shape of the seat face in response to an increase in pressure in the first annular area of the wellbore, wherein the shape of the seat face corresponds to a surface of the poppet for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in a closed position.
Example 2 is the annular safety valve of example(s) 1, further comprising: a second opening, wherein the housing defines the second opening by a second seat face; a second poppet extending through the second opening; and a second groove at least partially surrounding the second seat face for maintaining a shape of the second seat face in response to an increase in pressure in the first annular area of the wellbore, wherein the shape of the second seat face corresponds to a surface of the second poppet for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in the closed position.
Example 5 is the annular safety valve of example(s) 1-4, further comprising at least two additional openings, each opening of the two additional openings is associated with a respective groove at least partially surrounding each of the at least two additional openings.
Example 6 is the annular safety valve of example(s) 1-5, further comprising a seat insert positioned within opening, the seat insert having a seat face for maintaining a shape of the seat face in response to an increase in pressure in the first annular area of the wellbore, wherein the shape of the seat face corresponds to a surface of the poppet for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in a closed position in response to an increase in pressure in the first annular area of the wellbore.
Example 7 is an annular safety valve positionable in a wellbore, the annular safety valve comprising: a housing having an opening extending through the housing to allow pressure to transmit between a first annular area of the wellbore below the annular safety valve and a second annular area of the wellbore above the annular safety valve; and a poppet extending through the opening; at least one of (a) a seat insert positioned within opening, the seat insert having a sealing surface for maintaining a shape of the sealing surface in response to an increase in pressure in the first annular area of the wellbore, wherein the shape of the sealing surface corresponds to a surface of the poppet for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in a closed position in response to an increase in pressure in the first annular area of the wellbore, or (b) a groove at least partially surrounding the opening for maintaining a shape of the seat face in response to an increase in pressure in the first annular area of the wellbore, wherein the shape of the seat face corresponds to a surface of the poppet for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in a closed position.
Example 8 is the annular safety valve of example(s) 7, further comprising: a second opening in the housing; a second poppet extending through the second opening; and a second seat insert positioned within second opening, the second seat insert having a second sealing surface for maintaining a shape of the second seat face in response to an increase in pressure in the first annular area of the wellbore, wherein the shape of the second sealing surface corresponds to a surface of the second poppet for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in the closed position.
Example 9 is the annular safety valve of example(s) 7-8, further comprising at least two additional openings, each opening of the two additional openings is associated with a respective seat insert extending within each opening of the at least two additional openings.
Example 10 is the annular safety valve of example(s) 7-8, wherein the housing comprises a first material and wherein the seat insert comprises the first material.
Example 11 is the annular safety valve of example(s) 7-10, wherein the housing comprises a first material and wherein the seat insert comprises a second material that is different from the first material.
Example 15 is the annular safety valve of example(s) 7-14, wherein the sealing surface of the seat insert has a concave shape and wherein the surface of the poppet has a convex shape.
Example 16 is the annular safety valve of example(s) 7-15, further comprising a groove at least partially surrounding the opening for aiding in maintaining the shape of the sealing surface in response to an increase in pressure in the first annular area of the wellbore.
Example 17 is a downhole assembly positionable within a casing string of a wellbore comprising: a completion string including an annular safety valve, wherein the annular safety valve further comprises: a housing having a plurality of openings extending through the housing to allow to allow pressure to transmit between a first annular area of the wellbore below the annular safety valve and a second annular area of the wellbore above the annular safety valve, a plurality of seat faces, each seat face of the plurality of seat faces defining an opening of the plurality of openings; a plurality of poppets, each poppet of the plurality of poppets extending through a respective opening of the plurality of openings, wherein each poppet of the plurality of poppets has a surface that corresponds to a surface of each respective seat face for preventing pressure from transmitting between the first annular area of the wellbore and the second annular area of the wellbore when the annular safety valve is in a closed position; and a plurality of grooves, each groove of the plurality of grooves extending at least partially around a respective seat face of the plurality of seat faces for maintaining a shape of the respective seat face in response to an increase in pressure in the first annular area of the wellbore.
The invention relates to an annulus safety valve for use in a subterranean oil and/or gas well and to a method of controlling pressure within an annular area using the safety valve.
Just as safety valves must be provided to selectively sealingly block the interior of the production or workstring so that flow of fluid hydrocarbons from the production zone to the top of the well may be shut off at such safety valve to prevent a "blow out" in the event of an uncontrollable situation, such as fire, or the like, so the well "annulus" must likewise be controlled if it is exposed to a second production zone or is to be used for injection of fluid for one reason or another from the top of the well to a given production zone within the well.
While annulus safety valves have been utilized in the art, none are "full opening", so the internal diameter of such safety valve components for the annulus is not substantially equal to the internal diameter of the production or workstring, such that tools carried on remedial coiled tubing, wire or electric line, may safely and completely pass therethrough without any interference to longitudinal and/or rotational movement.
As set forth above, the purpose of such annulus safety valves herebefore utilized has been to control well pressure below such valves from communicating the tubing/casing annulus across such valves. It would be desirable to provide control of the annulus, yet permit selective injection of chemical inhibitor, kill fluid, and the like within the annular area between the tubing and casing from above the annulus safety valve to the area therebelow and within the interior of the casing on a selective volumetric basis.
Furthermore, it would be desirable to permit increased fluid flow across such annulus safety valve, selectively, merely by increase of fluid pressure within the tubing casing annulus above the annulus safety valve by permitting plug means which may be shearingly removed from sealing engagement within the valve to permit increase in fluid flow therethrough, such plug means also being replaceable by additional valve head and seat members of the same design and operation as other valve head and seat members forming the annulus safety valve.
The present invention addresses the above-identified problems and provides a unique annulus safety valve as described below and in the drawings incorporated herein.
The present invention provides a subterranean well annulus safety valve for control of fluid flow between outer and inner tubular conduits concentrically disposed within the well, said conduits extending from a first end of the safety valve to a point in the well.
The annulus safety valve comprises a cylindrical central housing securable to the inner of said tubular conduits. A fluid flow passageway is defined through the central housing and is in fluid flow communication with the interior of the inner of the tubular conduits.
Control valve means include valve head seat members which are disposed in the second housing with the head and seat members being in normally closed position to prevent fluid between the outer and inner tubular conduits from flowing through the central valve means, with the head and seat members being movable relative to one another to permit fluid flow through the control valve means.
The apparatus also includes, in one embodiment, a ported housing with a series of ports defined therethrough and circumferentially extending around the housing and at least one of the ports receiving the valve head and seat means.
The apparatus also includes pressure equalizing means within the ported second housing which is selectively movable while the valve head and seat means are in closed position from a first closed and sealed position to a second open pressure equalizing position to thereby equalize pressure across the valve head and seat means and the exterior of the central housing.
In the preferred embodiment, there is provided a series of valve head and seat members, with the valve head and seat members including members thereon to initiate movement of each of the valve head and seat members in sequence from a normally closed position to permit fluid flow therethrough in response, preferably, to varied application of pressure thereacross as well as when well pressure upstream of the members is greater than pressure downstream of such members.
As used herein, both in the claims and in the specification, the term "normally closed" means the position at which the valve head and seat members are located when there is no pressure differential thereacross.
FIG. 1 is a longitudinal section schematic illustration of a well incorporating the annulus safety valve system of the present invention, in schematic view.
FIGS. 3, 4, and 5 together are a more detailed view of the valve of FIG. 2, in one-quarter longitudinal section view, with FIG. 3 representing the uppermost portion of the valve, FIG. 4 representing the middle portion of the valve, and FIG. 5 representing the lowermost portion of the valve.
The end opposite the opening 123a of the ported second housing 105 defines a circumferentially subscribed angularly beveled metallic valve seat 107 for companion receipt of a valve head end 108a of a valve head member 108. These valve head and seat members are normally biased to the closed position, but are selectively openable upon either application of pressure through the opening 123a into the passage 123 from the top of the well, or, more preferably and conventionally, by means of application of hydraulic or pneumatic control fluid pressure through the control fluid passageway 301 extending to a control conduit (not shown), to the top of the well, as described hereafter. The valve head 108 and the valve seat 107 members together consitute the control valve means 106.
The valve mandrel 111 also has an enlarged lower head member 111a having a upwardly facing shoulder 111a" for selective abutting contact and engagement with a companion downwardly facing shoulder 114c and the shoulder 111a" defines the equalizing travel 305 required to equalize fluid across the apparatus 100 prior to the control mandrel 115 shifting the control valve means 106 to the open position subsequent to manipulation to the open position of the equalizing valve head 303 and the equalizing valve seat member shown in FIGS. 12 and 13.
In the preferred embodiment, there are a series of passageways 123 with openings 123a circumferentially defined through the ported second housing 105 with a plurality of control valve means 106 disposed therethrough. Approximately 180° from the first control valve means 106 is the equalizing valve means, including the equalizing valve seat member 302 and its equalizing valve head 303, as further described hereafter.
As shown in FIG. 11c, one or more of the passageways 123 may contain a plug element 200 which is secured to the ported second housing 105 by means of threads 201, shear pin, or the like, thus the plug means 200 replacing one or more of the control valve means 106.
The power spring 116 is, in effect, a biasing means and may be provided in the form of Belleville washers, a collapsible spring element, or the like. At any rate, the function of the biasing or power spring element 116 is to transmit a closing force from the inner conduit 102 through the control mandrel 115 to the control valve means 106, such that the valve head 108 is in sealing engagement with its companion valve seat 107 and the valve head end 108a extends, slightly, within the passageway 123. The force defined through the biasing means or power string 116 may, of course, be selectively varied, such that the control valve means 106 may be manipulated from the normally closed position to the open position to permit fluid flow through the passageway 123 at varied pressure.
Moreover, the biasing force through the power spring 116, together with the force defined through the control spring 112 may be selectively varied with respect to two or more control valve means 106, such that the various valve heads 106 within the ported second housing 105 may be serially manipulated to open position.
Alternatively, or concurrently, the size and configuration of the valve head 108 may be altered or varied, slightly, such that each of the control valve means 106 are manipulated to the open position upon various changes in fluid pressure encountered thereacross.
The annulus safety valve apparatus 100 of the present invention may be manipulated from the normally closed position, shown in the drawings, to the open position to permit fluid flow through the passageway 123 between the inner conduit 102 and the external or outer conduit B by means of application of hydraulic control pressure from the top of the well through the control conduit (not shown), which communicates into the control fluid passageway 301 and which is secured at threads 300 to the ported second housing 105.
Additionally, if it is desired to pump fluid in the tubing/casing annulus from the top of the well through the apparatus 100, thence through the packer in the annular area defined between the inner conduit 102 and the outer conduit B to the area of the well below the packer PKR, the control valve means 106 can be provided such that the bias towards the closed position defined as the power through the power spring 116 in combination with the control spring 112 can be varied such that any anticipated pressure through such annular area from the top of the well will open such control valve means 106 for injection purposes. However, it will be appreciated that by manipulating such control valve means 106 in such fashion, such control valve means 106 will not be able to be first manipulated to pressure equalizing condition and that such manipulation of the control valve means 106 should preferably be done only when pressure across the control valve means 106 is substantially equal and that there is no effective differential pressure thereacross which could adversely affect the sealing integrity of the valve members 108, 108a.
Referring now to FIGS. 12 and 13, for equalization purposes, an equalizing valve seat member 302 receives an equalizing valve head 303 defining the uppermost end of the valve head stem 311.
The equalizing valve head 303 is moved away from the the equalizing valve seat member 302 to equalizing position which is defined as the equalizing travel 305 between the shoulder 314c and the shoulder 311a between the valve mandrel 311 and the control mandrel 115. Until such equalizing travel 305 is completed, the control valve means 106 will not be moved from the normally closed position, thus enabling the equalizing valve members 302, 303 to be manipulated from fully closed position to fully open position prior to actuation of the control valve means 106, thus assuring that there is no differential pressure across the control valve means 106.
Now with reference to a hydraulic actuator 499 as shown in FIGS. 6-9, a sealing assembly 306, 307 provides a metal to metal seal to control fluid line. A piston collar 308 retains the seal assembly 306, 307 relative to the valve head stem 304. A piston member 309 is stationarily attached to the second ported housing 105 and locates a cylinder member 320. A metal to metal seal assembly is defined between the lowermost end 321 of the member 320 and the uppermost end 322 of cylindrical stop member 350 which, in turn, is secured at threads 323 to a cylindrical central housing member 324 which, in turn, is secured at threads to a lower closed end member 326.
The apparatus 100 will be run into the well W and positioned as shown in FIG. 1. When it is desired to open the control valve means 106, the apparatus 100 is first equalized by moving the equalizing valve head 303 from the equalizing valve seat member 302. This is effected by first applying an increase of pressure within the control fluid conduit through the passageway 301 to pressurize the interior of the cylinder below the lower dynamic wiper seal 327a to extend the cylinder away from the ported second housing 105. The cylinder stop 350 contacts the control mandrel 115 which moves the control mandrel 115 downwardly against the power spring 116 to compress such power spring 116. Now the shoulder 314c of the control mandrel 115 will move toward the shoulder 311a the distance of travel being the equalizing travel distance 305. As the shoulders 314c and the head 311a come together, the valve head 303 is stroked away from the seat member 302, thus permitting annulus fluid 401 to be equalized with pressure below the ported second housing 105. When the equalizing travel 305 is completed by continued application of fluid pressure through the control fluid passageway 301 from the control fluid line, the power spring 116 continues to be further compressed and one or more of the control valve means 106 are manipulated to open position with the valve head 108 being moved from the valve seat 107, respectively, depending upon the additional power defined through the control spring 112. Likewise, the control valve means 106 are manipulated to closed position by reduction in control fluid pressure through the control fluid conduit and the control fluid passageway 301, and the valve head means 106 are manipulated to closed position as the power in the spring 116 overcomes the fluid pressure in the control fluid passageway 301.
FIG. 3 is a view of the upper portion of annular safety valve 100 of the present invention in one-quarter longitudinal section view. Annular safety valve 100 includes ported second housing 105 which mates at threads 101 with production tubing A. The preferred annular safety valve 100 of the present invention includes two paths for receiving fluid. The first is a connector 509 which is adapted for coupling to a high pressure fluid hose which provides a control fluid to annular safety valve 100 of the present invention. Fluid directed from the control line of the high pressure hose is directed inward into annular safety valve 100 via fluid passage 301. The second opening is passageway 123, which will allow wellbore fluid in the annular region between tubing string 101 and casing C to pass through when valve 106 is in open condition.
FIGS. 11a and 11b show connector 509 and valve 106 in enlarged view. As shown in FIG. 11a, valve 106 includes valve head 108 which releasably engages valve seat 107. As shown, valve seat 107 is merely a circular passageway which is adapted in size and shape to sealingly engage a tapered portion of valve head 108. In the preferred embodiment of the present invention, valve head 108 and valve seat 107 are maintained in a normally-closed position, and cooperate in preventing the passage of fluid into annular safety valve 103, until a predetermined amount of pressure is applied by a high pressure hose to control port 301. As shown in FIG. 11b the uppermost extent of control port 301 is threaded or otherwise adapted to receive a control hose fitting 300. In the preferred embodiment of the present invention, other fluid passageways 123 and valve assemblies 106 are provided circumferentially around annular safety valve 100. Fluid passageways 123 which are not equipped with valve assemblies 106 may be plugged, as shown in FIG. 11c.
FIG. 10 is a cross-section view of annular safety valve 100 of the present invention in full cross-section view, as seen along lines A--A of FIG. 3. As shown, a plurality of valve assemblies 106 are provided, preferably three, each positioned 90 degrees apart. Also shown in FIG. 10 are fluoroplastic bearings 505 which receive guide members 507.
Returning now to FIG. 3, as shown, valve head 108 is biased upward relative to control mandrel 115 by spring 112, into normally-closed sealing engagement with valve seat 107. As shown, valve seat 107 is merely the end portion of ported second housing 105, which is equipped with a cylindrical fluid passage 123, and which is adapted in size and configuration to sealingly engage valve head 108a of valve member 108, when it is biased upward by spring 112. Valve head 108a is integrally formed with valve mandrel 111. Valve mandrel extends through the central region of spring 112, and is adapted to slidably engage a stationary piece 111a.
In the preferred embodiment of the present invention, high pressure fluid is directed from a high pressure fluid hose through fluid passage 301. The high pressure fluid operates to move a hydraulic actuator 499 between a normally-closed position and an open position, which serves to equalize the fluid pressure differential across annulus safety valve 100. In the preferred embodiment, as hydraulic actuator 499 is moved between a normally-closed position and an open position, control mandrel 115 (which extends circumferentially around inner conduit 102) is urged downward relative to inner conduit 102, causing valve assembly 106 to be moved from a normally-closed position and an open position, allowing annulus fluid to flow through the annulus safety valve 100.
The operation of hydraulic actuator 499 is graphically disclosed in FIGS. 6, 7, 8, and 9. FIGS. 6 and 7 together depict hydraulic actuator 499 in its normally-closed position. FIGS. 8 and 9 together depict hydraulic actuator 499 in an open position. The relative positions of hydraulic actuator 499 and valve assembly 106 is graphically disclosed in FIG. 12.
As shown in FIG. 4, movement of central mandrel 115 downward relative to inner conduit 102 causes compression of power spring 116. Therefore, as soon as high pressure fluid of a sufficient amplitude is no longer provided to fluid passage 301 to actuate hydraulic actuator 499, power spring 116 will urge control mandrel 115 upward relative to inner conduit 102, causing valve head 108a to engage valve seat 107, thus preventing the passage of fluid between annular safety valve 100 and fluid passageway 123.
FIG. 5 shows the lower end of annulus safety valve 100 of the present invention. As shown, annulus safety valve 100 is provided with external threads 122, which releasably engage a conventional wellbore packer assembly.
As shown in FIG. 6, piston lock nut 320 is secured in position relative to ported second housing 105 by threads 511. At its uppermost end, piston 309 includes piston stem 304, which is circumferentially engaged by piston collar 308 and seal assembly 306, 307. Piston lock nut 320 is provided exteriorly of piston 309. Piston lock nut 320 is in abutting relationship with cylindrical stop 350. Cylinder stop 350 and cylinder 324 are coupled together at threads 513. Annular region 515 is provided between stationary piston 309 and movable cylinder 324.
The discussion and exposition of hydraulic actuator 499 will continue with reference to FIG. 7. As shown, a number of components are provided in annular space 515 between stationary piston 309 and movable cylinder 324. These components include seal 325a, spring 325, and bearing 326. In addition, wiper seal 327 is provided in annular space 515 between stationary piston 309 and movable cylinder 324. Also provided in annular space 515 are support ferrule 328, lower wiper seal 327a, bearing 329, and wedge 330. All of the above components in annular space 515 are held in position by lock nut 331. These components do not interfere with the movement of piston 309 relative to movable cylinder 324.
At its lowermost end, stationary piston 309 terminates at seat 333, which engages plug stop seat 332, in a normally-closed mode of operation. The components disposed in annular space 515 between stationary piston 309 and movable cylinder 324 do not interfere with the movement of movable cylinder 324 relative to stationary piston 309. As high pressure fluid is directed downward within piston fluid channel 501 of stationary piston 309, force is exerted against plug stop seat 332.
Plug stop seat 332 is coupled to cylinder plug 326, and engages expander shim 334 at its lowermost end. Expander shim 334 engages spring 335. As fluid pressure is applied to the seat 333 of plug stop seat 332, plug stop seat 332 is urged downward relative to stationary piston 309, and causes expander shim 334 to compress spring 335. As seat 333 is brought out of contact with the lowermost end of stationary piston 309, fluid is allowed to enter the annular space 305 between cylinder 324 and piston 309. The pressure differential created across wiper seals 327, causes movable cylinder 324 to be urged downward relative to stationary piston 309, as shown more fully in FIGS. 8 and 9.
As shown in FIGS. 8 and 9, the preferred hydraulic actuation device 499 of the present invention is moved by high pressure fluid to an open position, with movable cylinder 324 moved downward relative to stationary piston 309. As shown in FIG. 8, cylinder stop 350 and piston lock nut 320 are separated by distance D1. This distance of travel is an amount sufficient to move valve head 108a a selected distance away from valve seat 107.
FIG. 12 is fragmentary longitudinal section view of annulus safety valve 100, which depicts the interrelationship between hydraulic actuator 499 and equalizing valve assembly 521. As movable cylinder 324 is moved downward, to the right, relative to stationary piston 309, in response to high pressure fluid directed downward through passage 301 to piston fluid channel 501, control mandrel 115 is likewise moved downward (to the right) along with movable cylinder 324. As discussed above, control mandrel 115 extends circumferentially around inner conduit 102, and thus will move valve head 303 out of sealing engagement with valve seat 302, causing equalizing valve 521 to be moved a selected distance 305 to allow equalization of pressure across annular safety valve 100. As shown in FIG. 12, equalizing valve 521 is similar in construction to valve members discussed above, and includes spring 525 which biases valve head 303 against valve seat 302. Valve head 303 is integrally formed and coupled with valve stem 311, which is movable downward relative to stationary guide pieces 527, 529, 531.
FIG. 13 is a fragmentary, longitudinal section view of the preferred annular safety valve 100 of the present invention, which depicts the relationship between valve assembly 106, and equalization valve assembly 521.
As shown in FIG. 13, when equalization valve assembly 521 is in an open condition, valve assembly 106 remains in its normally-closed condition, with valve head 108 sealingly engaging valve seat 107. The fluid path 551 which supplies fluid to equalizing valve assembly 521 is a tiny fluid path, much smaller in cross-sectional area than the fluid passage which provides fluid to valve assembly 106. The fluid path 551 of FIG. 13 allows for minute quantities of extremely high pressure fluid to be passed through annular safety valve 100 to equalize the pressure differential across annular safety valve 100 before valve head 108 is brought out of sealing engagement with valve seat 107. This is a safety feature which prevents catastrophic failure which frequently occurs when valves are open at high pressure differentials.
In broad terms, the present invention, valve assembly 106, hydraulic actuator 499, and equalizing valve assembly 521 cooperate together to allow the passage of fluid through annular safety valve 100. The process begins when hydraulic actuator 499 is actuated, so that movable cylinder 324 is displaced relative to stationary piston 309, in response to high pressure fluid directed into annular safety valve 100 by a high pressure hose (or control line). Movement of movable cylinder 324 relative to stationary piston 309 causes equalizing valve assembly 521 to move between a normally-closed position and an open position, to equalize pressure across annulus safety valve 100 prior to movement of valve assembly 106 between a normally-closed position and an open position. Valve assembly 106 is the final component in annular safety valve 100 which moves between closed and open positions.
In the preferred embodiment of the present invention, a plurality of valve assemblies 106 may be provided circumferentially about inner conduit 102, all mechanically coupled together by central mandrel 115, which extends circumferentially about inner conduit 102. Each of the plurality of valve assemblies 106 may be calibrated to open at a different fluid pressure level which is provided by a high pressure hose or control line, by fixing the length and position of valve mandrel 111 relative to control mandrel 115. For example, one valve assembly 106 may be adapted to open upon movement of movable cylinder 324 relative to stationary piston 309 by a selected distance D1. A second valve assembly 106 may be adapted to open at another, different distance D2 of travel of movable cylinder 324 relative to stationary piston 309. A third and final valve assembly 106 may be provided to move between closed and open positions upon movement of movable cylinder 324 relative to stationary piston 309 by a predetermined longer distance D3. As high pressure fluid is supplied to hydraulic actuator 499, it will move first to distance D1, then to distance D2, and finally to distance D3. Thus, the plurality of valve assemblies 106 may be sequentially and successively actuated at predetermined pressure thresholds. Of course, equalizing valve assembly 521 will actuate prior to any of valve assemblies 106 to equalize the high pressure differential across annular safety valve 100. In other embodiments, multiple equalizing valve assemblies 521 may be provided.
Finally, the present invention need not communicate with high pressure hoses or control lines. Instead, the annular region between the tubing and casing may be pressurized with a wellbore pump, or surface pump, to obtain sufficient pressure levels to operate hydraulic actuator 499, equalizing valve assembly 521, and one or more valve assemblies 106.
Surface-controlled subsurface safety valves (SCSSVs) are critical components of well completions, preventing uncontrolled flow in the case of catastrophic damage to wellhead equipment. Fail-safe closure must be certain to ensure proper security of the well. However, this is not the only function in which it must be reliable—the valve must remain open to produce the well. Schlumberger surface controlled subsurface safety valves exceed all ISO 10432 and API Spec 14A requirements for pressure integrity, leakage acceptance criteria, and slam closure.
Through decades of innovation and experience, Schlumberger safety valve flapper systems are proven robust and reliable. The multizone dynamic seal technology for hydraulic actuation of subsurface safety valves is a further improvement in reliability performance when compared with traditional seal systems in the industry.
The multizone seal technology is currently available in the GeoGuard high-performance deepwater safety valves, which is validated to API Spec 14A V1 and V1-H.
The safety system of this invention is usable to control flow of fluids in a well wherein the well environment may include high pressure conditions, such as 20,000 psi gas pressures; high corrosive fluids, such as H2 S or CO2 ; and/or high temperatures, all of which are detrimental to resilient seals.
The combination of a tubing safety valve and an annulus safety valve to control flow of fluids within a well is disclosed by U.S. Pat. No. 3,035,642 to J. S. Page; U.S. Pat. No. 3,313,350 to J. S. Page, Jr.; and U.S. Pat. No. 3,252,476 to J. S. Page, Jr. Annulus safety valves for controlling flow in the annulus between concentric well pipe are disclosed by U.S. Pat. Nos. 3,045,755; 3,156,300; both to Page, et al and U.S. Pat. No. 3,299,955 to J. S. Page, Jr.
Some of the aforementioned safety valves have been commercialized as illustrated on pages 4115 through 4117 of the "COMPOSITE CATALOGUE OF OIL FIELD EQUIPMENT & SERVICES", 1974-1975 edition.
The present annulus safety valves in combination with tubing safety valves, provide controlled flow through concentric well pipes. However, in the high temperature, high corrosive, and/or high pressure environment of some wells, these annulus safety valves are insufficient.
The valve member of the aforementioned U.S. Pat. Nos. 3,035,642; 3,253,476; and 3,156,300; and the valve member illustrated in the "COMPOSITE CATALOGUE" is moved in response to pressurizing a pressure chamber. The resilient seals of the pressure chamber are exposed to the well environment even after the valve member closes the annulus flow path. The high corrosive, and/or high temperature well environment could deteriorate these resilient seals and high pressure well fluids could blowout through the pressure chamber.
All of the aforementioned annulus safety valves utilize a sleeve valve member with resilient seals to block the annulus flow. The resilient seals may deteriorate and leak. It is not economically feasible to obtain a metal to metal seal with a sleeve valve member because expansions and contractions due to temperature variations cannot be accommodated and because sand collects around the sleeve valve member and inhibits a good metal to metal seal. Also, with a sleeve valve, the higher the fluid pressure of the fluid contained by the valve, the greater the tendency of the valve to leak.
The aforementioned annulus valves, except for the U.S. Pat. No. 3,035,642, disclose utilizing a valve member which closes the annulus flow path at a position other than at its upstream end. Additionally the valve housing is not integral. Therefore, potential leak paths from the annulus flow path through the valve housing exist. Even though the valve member closes the annulus flow path, the safety valve could fail to perform its function of shutting in the well due to a leakage through one of these potential leak paths.
The aforementioned annulus valves, except for the U.S. Pat. No. 3,035,642, all have a tortuous annulus flow path. High velocity flow of well fluids through these tortuous flow paths cause flow cutting of valve components and/or the surrounding well pipe.
The aforementioned U.S. Pat. No. 3,035,642 has a metal to resilient seal between a sleeve valve member and a resilient packer. The resilient seat could deteriorate in a high corrosive well environment preventing a good seal with the sleeve valve member.
Problems with the aforementioned annulus safety valves can be summarized as follows: Valve components, including the operating means for the valve member, are subject to downhole well fluids even though the valve member is in a position closing the annulus flow path. There is more than one seal location, and thus additional structures to seal, even though the valve member is in a flow path closing position. The greater the well pressure the greater the likelihood that the valve will fail due to leakage past the sleeve valve member. The resilient seals may deteriorate and/or prove ineffective in some well environments. Additionally the tortuous flow path through the valve member results in flow cutting of either the valve member or the surrounding well pipe.
An object of this invention is to provide a surface controlled subsurface annulus safety valve wherein the control chamber and its seals are isolated from upstream well fluids or pressure when the valve is in a closed position.
Another object of this invention is to provide a surface controlled subsurface annulus safety valve in which the operating piston is protected against a large pressure differential when the valve is closed.
Another object of this invention is to provide a surface controlled subsurface annulus safety valve with only one sealing location among the valve housing and valve member components.
Another object of this invention is to provide a surface controlled subsurface annulus safety valve wherein, when the valve is closed, the greater the downhole well pressure, the more effective the seal provided by the valve.
Another object of this invention is to provide a surface controlled subsurface annulus safety valve having a substantially straight through flow path to eliminate flow cutting and having a control chamber whose seals are isolated from upstream well fluids or pressure when the valve is closed.
Another object of this invention is to provide a surface controlled subsurface annulus safety valve having a control chamber whose seals are disposed out of the fluid flow path through the valve to minimize the likelihood of control chamber seal failure due to erosion or deterioration.
Another object of this invention is to provide a surface controlled subsurface safety system for controlling flow in concentric well pipes including a tubing safety valve to control flow in the inner pipe and an annulus safety valve to accomplish any of the aforementioned objects, the safety system including a single control conduit to control the operation of both valves.
To control the flow of well fluids in the annulus 18 an annulus safety valve 20 may be provided. Because of the environmental conditions encountered in some wells, there are certain desirable features for an annulus safety valve 20. The annulus safety valve 20 should have a high pressure rating on the order of 20,000 psi. The closed valve 20 should seal against high pressure well fluids even at high temperatures and even though the well fluids are highly corrosive. When the valve 20 is open, it should provide a relatively straight, non-tortuous, baffle-free flow path to minimize flow cutting of valve parts and the surrounding well pipe. Preferably, the valve 20 is controlled from the surface, and the control system should be arranged so that the valve is not accidentally or unintentionally opened. As illustrated in FIG. 1, control conduit means 22 extends from the surface to the valve 20 to control the valve 20. Through control conduit means 22 hydraulic control fluid may be pumped to pressurize a chamber to in turn open the annulus safety valve 20.
To control the flow of well fluids in the bore or the inner pipe 16 a tubing safety valve may be provided. The tubing safety valve is controlled by fluid pressure transmitted to it through conduit means extending from the surface to the tubing safety valve. The tubing safety valve control conduit may be a separate conduit. However, to simplify the controls of the subsurface safety system, both the annulus safety valve 20 and the tubing safety valve are controlled by pressurized fluid conducted to them through conduit means 22.
The annulus valve includes mandrel means 24 forming a portion of the inner pipe, passage means 26 through mandrel means 24, valve member means 28 to control flow through passage means 26, and means for operating the valve member means 28.
With this arrangement of mandrel means 24, including flange means 36 through which extend passage means 26, an integral housing is provided for the annulus safety valve. Therefore only one main seal, packer means 32, exists, in addition to the seal provided by the valve itself.
To provide a portion of the valve seal, valve seat means 38 on mandrel means 24 is associated with passage means 26. Preferably, valve seat means 38 is located at the upstream end of passage means 26 so that when it is engaged by valve member means 28, the means for operating the valve member means 28, including the operating piston, the pressure chamber and their respective seals, are protected from the downhole well environment and isolated from the upstream well pressure. If passage means 26 includes the plurality of passageway means extending through flange means 36, then, valve seat means 38 may comprise an annular valve seat means on the lower surface 36a of flange means 36.
Valve member means 28 controls the flow of well fluids through passage means 26. Valve member means 28 is axially movable on mandrel means 24 between a position wherein its valve head means 40 sealingly engages valve seat means 38 to block flow through passage means 26 and a position spaced from valve seat means 38 to permit flow through passage means 26.
Preferably, a metal to metal seal is provided by the engagement of valve head means 40 with valve seat means 38. Thus, the valve seat means 38 may be an abutment valve seat means with valve head means 40 being a metal abutment valve head means.
If valve seat means 38 comprises an annular valve seat means, then valve member means 28 would comprise an annular valve member means surrounding mandrel means 24.
To provide for a fail-safe, normally-closed annulus safety valve, means are provided for biasing valve member means 28 to a position engaging valve seat means 38. Preferably, spring biasing means 42 is provided to positively bias valve member means 28 to a position engaging valve seat means 38. A spring biasing means 42 would be relatively unaffected by an adverse downhole well environment. The illustrated spring biasing means 42 is shown positioned between a shoulder 44 of valve member means 28 and collar means 46 surrounding mandrel means 24.
Means are provided to move valve member means 28 to a position remote from valve seat means 38 to open passage means 26 to fluid flow by-passing packer means 32. A portion of this moving means comprises chamber means 48 including pressure responsive means 50 adapted to move valve member means 28 when chamber means 48 is pressurized.
Preferably chamber means 48 is protected from the downhole well environment, which may comprise high pressure, highly corrosive well fluids, and high temperatures, when valve member means 28 engages valve seat means 38. To protect chamber means 48 when the annulus safety valve is closed, chamber means 48 is located downstream of valve seat means 38; e.g., a chamber means 48 is located on the side of valve seat means 38 opposite valve member means 28.
The illustrated chamber means 48 is formed by utilizing a portion of at least one passageway (See FIGS. 4 and 5) downstream from valve seat means 38 (See FIGS. 2 and 3) with pressure responsive means 50 disposed in chamber means 48. Pressure responsive means 50 includes piston head means 50a having seal 52 around it to seal with the wall of chamber means 48. Piston head means 50a is adapted to slide axially within chamber means 48 in response to sufficient pressurizing or depressurizing of chamber means 48.
To move valve member means 28 when chamber means 48 is pressurized, rod means 53 depends from piston head means 50a and is attached to valve member means 28.
When chamber means 48 is sufficiently pressurized, pressure responsive means 50 will move to the position illustrated in FIG. 2B with valve member means 28 remote from valve seat means 38. When chamber means 48 is depressurized, spring biasing means 42 will move valve member means 28 to a position engaging valve seat means 38 as shown in FIG. 3.
Means are provided to pressurize chamber means 48. Port means 54 communicates with chamber means 48 and is adapted to be connected to conduit means 22 extending from the surface. Pressurized hydraulic control fluid is pumped through conduit means 22 to chamber means 48 to control the annulus safety valve.
Means are provided to prevent rotation of the annular valve member means 28 about the mandrel means 24. The anti-rotation means may be axial slot means 55 along mandrel means 24 engaged by pin means 56 carried by valve member means 28.
To control fluid flow in the bore 30 of tubular mandrel means 24, a tubing safety valve is provided. The tubing safety valve may be any conventional tubing safety valve. However, in a harmful well environment, the tubing safety valve should provide a metal to metal seal to effectively close the bore 30 to the flow of well fluids and should protect the piston chamber means from the influence of downhole well fluids or pressure when the tubing safety valve is closed.
Valve member operator means 62 moves the valve member means 60 and is itself movable between a first position wherein valve member means 60 opens the bore 30 (see FIG. 2B) and a second position wherein valve member means 60 closes the bore 30 (see FIG. 3).
The means for moving valve member operator means 62 include means 64 for biasing valve member operator means 62 to its second position and a controlled means for moving the valve member operator means 62 to its first position.
The control means, including piston chamber means 66 and piston means 68, is adapted to move valve member operator means 62 to its first position when piston chamber means 66 is sufficiently pressurized.
The hydraulic controls of the illustrated safety system are simplified by including single conduit means 22 extending from the surface to the valves to transmit control fluid to both chamber means 48 and piston chamber means 66. Communicating means are provided between piston chamber means 66 and chamber means 48. The illustrated communicating means 70 includes port means 70a in the tubing safety valve housing in communication with piston chamber means 66, port means 70b in tubular mandrel means 24 in communication with chamber means 48, and annular groove means 70c in tubular mandrel means 24 in communication with both port means 70a and 70b. Although port means 54, which is connected to conduit means 22, communicates with chamber means 48, it could communicate with any one of chamber means 48, piston chamber means 66, or communicating means 70.
Means are provided to lock the retrievable tubing safety valve within recess means of tubular mandrel means 24. Any means may be provided which locks the tubing safety valve within tubular mandrel means 24 against upward movement. Due to the high formation pressures which may be encountered and which will act upwardly through the inner well pipe against the tubing safety valve, the releasable locking means must be able to withstand a considerable pressure differential across the tubing safety valve.
The illustrated releasable locking means (FIG. 2A) generally indicated at 72 is of a type which locks when it enters a suitable recess 74. The releasable locking means 72 may be unlocked and the tubing safety valve retrieved from the tubular mandrel means 24 by an appropriate fishing tool (not shown).
In operation, the safety system of this invention includes an annulus subsurface safety valve and may include a tubing subsurface safety valve when it is desired to control flow in both the tubing bore and the annulus between concentric well pipes. The inner well pipe 16 is run with tubular mandrel means 24 and other associated parts of the annulus safety valve assembled thereon. A tubing safety valve may be installed in the bore of the inner well pipe 16.
To open the valves and permit fluid flow, conduit means 22 is pressurized. The hydraulic control fluid from conduit means 22 pressurizes chamber means 48 of the annulus subsurface safety valve and piston chamber means 66 of the tubing safety valve. Pressure responsive means 50 moves the annulus safety valve member means 28 to a position remote from valve seat means 38 to open passage means 26 to fluid flow in the annulus 18 by-passing packer means 32. Likewise piston means 68 moves valve member operator means 62 to its first position with the tubing safety valve member means 60 opening the bore 30 to fluid flow.
When it is desired to stop the flow of fluid in the well, control conduit means 22 is depressurized. Spring biasing means 42 of the annulus safety valve provides an upward acting force against annulus valve member means 28 to overcome the hydrostatic head of fluid within conduit means 22 acting downwardly upon the pressure responsive means 50. The upward acting force of spring biasing means 42, assisted by downhole well pressure, moves valve member means 28 to a position engaging valve seat means 38 to close the annulus flow path. Likewise, biasing means 64 of the tubing safety valve provides an upward acting force on valve member operator means 62 to overcome the hydrostatic head of force acting downwardly on piston means 68. The valve member operator means 62 is moved to its second position and valve member means 60 is moved to a bore 30 closing position.
If desired, the relative biasing forces of spring biasing means 42 of the annulus safety valve and of biasing means 64 of the tubing safety valve may be varied so that either valve may close first or so that both valves may close substantially simultaneously.
With the illustrated construction of the annulus safety valve, once the annulus safety valve is closed a slight unintentional rise of pressure in control conduit means 22 above that of the downhole well pressure will not open the annulus safety valve. This is because the area of piston head means 50a is small compared with the area sealed by the annulus valve member means 28. Thus, pressure sufficiently in excess of downhole well pressure must be exerted on pressure responsive means 50 to move valve member means 28 to a position remote from valve seat means 38. Pressure sufficiently above that of the downhole well pressure would only be introduced in conduit means 22 intentionally. Slight increases in pressure in conduit means 22, which may happen unintentionally, would not open the annulus safety valve.
Likewise, once the tubing safety valve is closed, it will not open in response to ordinary pressures in conduit means 22. This is because the area of piston means 68 is also small compaired with the area sealed by valve member means 60. The difference in areas means that a sufficiently high pressure, in excess of downhole well pressure, would have to be transmitted to piston chamber means 66 to move valve member means 60 to a position opening the bore 30. It is not likely that such a high pressure would ever be applied unintentionally.
From the foregoing it may be seen that an improved subsurface safety valve system has been provided. The subsurface safety valve system controls flow through concentric well pipe and includes an annulus safety valve and may include a tubing safety valve.
The annulus safety valve provides abutment, metal to metal sealing of valve member means with valve seat means. This seating insures an adequate seal in a high pressure, high corrosive, and high temperature well environment.
The annulus safety valve has an integral, single component housing. Therefore when the valve is closed, fluids upstream in the annulus are confined by one main packer seal and the valve seating seal. Other potential leak paths are nonexistent.
The valve seating location is at the upstream end of the annulus flow path through the annulus safety valve thereby protecting the deteriative and pressure sensitive components of the annulus safety valve from the downhole well fluids when the valve member seats against the valve seat. In particular, the chamber and control conduit are protected from the downhole well fluids and a high pressure differential.
The tubing safety valve is usable with the annulus safety valve and also provides a metal to metal seal and protects the piston chamber when the valve is closed.
The hydraulic controls for the safety system are simplified by including a single control conduit through which fluid is pumped to control both the annulus safety valve and the tubing safety valve.
Abstract: An annular safety valve sealing package comprises an annular safety valve comprising a tubular housing; a first annular sealing element comprising a first elastomeric material and disposed about the tubular housing of the annular safety valve; a second annular sealing element comprising a second elastomeric material and disposed about the tubular housing of the annular safety valve adjacent the first annular sealing element; and a third annular sealing element comprising a third elastomeric material and disposed about the tubular housing of the annular safety valve adjacent the second annular sealing element and on an opposite side of the second annular sealing element from the first annular sealing element. At least two of the first elastomeric material, the second elastomeric material, or the third elastomeric material have different compositions.
Abstract: An annular safety valve sealing package comprises an annular safety valve comprising a tubular housing; a first annular sealing element comprising a first elastomeric material and disposed about the tubular housing of the annular safety valve; a second annular sealing element comprising a second elastomeric material and disposed about the tubular housing of the annular safety valve adjacent the first annular sealing element; and a third annular sealing element comprising a third elastomeric material and disposed about the tubular housing of the annular safety valve adjacent the second annular sealing element and on an opposite side of the second annular sealing element from the first annular sealing element. At least two of the first elastomeric material, the second elastomeric material, or the third elastomeric material have different compositions.
Abstract: An annular safety valve sealing package that is suitable for use in the presence of an acid gas and that is capable of retaining its material properties when the annular safety valve is retrieved is provided. The annular safety valve sealing package includes an annular safety valve having a tubular housing, a first annular sealing element including a first elastomeric material and disposed about the tubular housing, a second annular sealing element including a second elastomeric material and disposed about the tubular housing, and a third annular sealing element including a third elastomeric material and disposed about the tubular housing on an opposite side of the second annular sealing element from the first annular sealing element. At least two of the first elastomeric material, the second elastomeric material, or the third elastomeric material have different compositions.
Abstract: The present invention relates to seal ring back-up devices suitable for use on glands in sealing systems. In particular, the present invention relates to seal ring back-up devices that have been designed to fit into essentially all types of glands and close extrusion gaps. Some embodiments of the present invention provide a seal ring back-up device having an annular body having an inner diameter, an outer diameter, and a scarf cut; and where the annular body is configured to fit a gland and engage a seal ring.
Abstract: An annular safety valve sealing package comprises an annular safety valve comprising a tubular housing; a first annular sealing element comprising a first elastomeric material and disposed about the tubular housing of the annular safety valve; a second annular sealing element comprising a second elastomeric material and disposed about the tubular housing of the annular safety valve adjacent the first annular sealing element; and a third annular sealing element comprising a third elastomeric material and disposed about the tubular housing of the annular safety valve adjacent the second annular sealing element and on an opposite side of the second annular sealing element from the first annular sealing element. At least two of the first elastomeric material, the second elastomeric material, or the third elastomeric material have different compositions.
Abstract: The present invention relates to seal ring back-up devices suitable for use on glands in sealing systems. In particular, the present invention relates to seal ring back-up devices that have been designed to fit into essentially all types of glands and close extrusion gaps. Some embodiments of the present invention provide a seal ring back-up device having an annular body having an inner diameter, an outer diameter, and a scarf cut; and where the annular body is configured to fit a gland and engage a seal ring.
The present invention relates to an impr