AU610385B2 - Surface controlled subsurface safety valve - Google Patents

Description

io tho Comm lofi on r of iaItanto m1flmonwOal i of Auntralln VT' IF1 At. 7,TED AND AINAU ND TS Ai.L A Yr' LD 11# w 0, IfI II iH 4 4fI FI I14f 1 0f 11 o t0 i Ij ii II 21 I_ I 6180385 COMMONWEALTH OF AUSTRALIA Putants Aot 1952 COMPLETE SPECIFICATION (Original) FOR OFFICE USE Application Number: Class Lodged; Class Int.

Complete Specification Lodged: Accepted; Published: Priority: Related Art; 1.his document contains the anlundtents made unLdr Section ei9 and is correct for priting, TO BE COMPLETED BY APPLICANT Name of Applicants: OTIS ENGINEERING CORPORATION Address of Applicants: P 0 Box 819052, Dallas, Texas, 75381- 9052, United States of America.

Actual.

SIZER,

Robert Inventors: Michael Burl VTNZANT, Phillip Spelman Ronald Keith CHURCHMAN, Rennie Lee DICKSON and Roddie

SMITH.

S Address for Service:- Wray Associates Primary Industry House 239 Adelaide Terrace Perth Western Australia 6000.

Complete Specification for the invention entitled: "SURFACE CONTROLLED SUBSURFACE SAFETY VALVE" The following statement is a full description of this invention, including the best method of performing it known to us:- 1 A

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-2- This invention relates to surface controlled subsurface safety valves used in the oil and gas industry and is particularly concerned with a mechanism for temporarily locking the valves open and for remedial cycling of the valves.

It is common practice to complete oil and gas producing wells with systems including a subsurface safety valve controlled from the well surface to shut off fluid S" flow in the well tubing string. Generally such a valve is controlled in response to control fluid pressure conducted 00 o o to the valve from a remote location at the well surface via 04 00 0 0 a small diameter conduit permitting the well to be o selectively shut in as well conditions require. However, the present invention is not limited to use with safety *0 '115 valves that respond only to fluid pressure signals. The S' surface controller is typically equipped to respond to emergency conditions such as fire, broken flow lines, oil spills, etc. Frequently it is necessary to conduct well servicing operations through a subsurface safety valve.

20 When a safety valve malfunctions, it may be necessary to install a second safety valve. In any event, it may be desirable either permanently or temporarily to lock the safety valve open. For example, if the ,well servicing operation requires a wireline tool string to extend through 4 1 1 -3 the subsurface safety valve, it is preferable to use a lock open system which is not dependent upon control fluid pressure from the well surface. When operations are being carried out through an open subsurface safety valve such as pressure and temperature testing, it can be extremely expensive and time-consuming for a valve to accidentally close on the supporting wireline causing damage to the wireline and sensing apparatus supported therefrom.

Additional well servicing procedures are required to retrieve the damaged equipment. Subsurface safety valves including both permanent and temporary lock open mechanism are disclosed in United States Patents Nos. 3,786,865; 3,882,935; 4,344,602; 4,356,867; and 4,449,587. The present invention particularly relates to a subsurface safety valve of the type concerned in United States Patent Nos. 3,786,865 and 4,449,587 employing a temporary lockout arrangement for the flapper type of valve closure included in the subsurface safety valves. These listed prior patents are incorporated by reference for all purposes in 'Chis application.

In tubing retrievable flapper type safety valves having a housing connectable with a well tubing string and a bore therethrough for communicating well fluid flow with the tubing string, the flapper valve is mounted in the housing for movement between a first open position and a -4second closed position, and an operator tube may be provided in the housing to shift the flapper valve between its second position and its first position. The operator tube normally moves in response to a control signal from the well surface but a shifting tool can releasably engage the operator tube for movement independent of the control signal. A lockout sleeve may be mounted in the housing in tandem with the operator tube for movement between a first position engaging and holding the flapper valve open and a second position of disengagement from the flapper valve.

The present invention is concerned with a shifting 000 tool having means for releasabJly coupling with the operator 09 0 0 0 0 tube and the lockout sleeve, respectively, of safety valves 04 01 o0 S 4 of this kind. Shifting tools in accordance with the present invention can be arranged to be used with other 0000 00 types of surface controlled subsurface safety valves, 044* however, to cycle the valve closure mechanism if it is 0 49 4 stuck or the control signal is inoperative.

According to the inventio-i, there is provided a shifting tool for use in operating a lockout sleeve of a well safety valve comprising inner core means slidably disposed within a housing means, means for attaching one end of the inner core means to a wireline tool string, first means for releasably engaging the inner core means to the housing means to prevent relative movement therebetween, selective profile keys projecting radially through first windows in the housing means, latch dogs projecting radially through second windows in the housing means and spaced longitudinally from the selective keys, the first releasable means holding the inner core means in a first position which allows compression of the selective keys and latch dogs radially inward, and second means for releasably engaging the inner core means to the housing means and holding both the selective keys and the latch dogs radially expanded.

According to a further form of the invention, there is provided a shifting tool for use in operating a lockout sleeve of a well safety valve comprising inner core means slidably disposed within a housing means, means for attaching one end of the inner core means to a wireline o o tool string, first means for releasably engaging the inner 0 core means to the housing means to prevent relative o0000 movement therebetween, selective profile keys projecting 00 radially through first windows in the housing means, the 00 0@ :o first releasable means holding the inner core means in a 0 first position which allows compression of the selective a° a 4 0 keys radially inward, and second means for releasably engaging the inner core means to the housing means and holding the selective keys radially expanded.

0r0c Preferably said shifting tool further comprises latch dogs projecting radially through second windows in the housing means and spaced longitudinally from the selective keys, said first and second releasable engagement means also respectively allowing compression of the latch dogs radially inwards and holding the latch dogs radially expanded.

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By way of example, the invention will be described in more detail with reference to the accompanying drawings in which:- Figure 1 is a schematic sectional elevation illustrating a typical well completion including a tubing retrievable subsurface safety valve with a flapper type valve closure means; Figures 2A, 2B, 2C and 2D taken together form a longitudinal part-sectional elevation illustrating a subsurface safety valve and lockout sleeve showing the safety valve in its open position; 9 0o o 9 o 9 0 0 e 0

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/v o i arY~x-r* -iri I- 6 Figs. 3A and 3B taken together form a longitudinal part-sectional elevation illustrating one embodiment of the shifting tool of the present invention; Fig. 4 is a section taken along the line 4-4 of Fig. 3; Figs. 5A, 5B and 5C taken together form a longitudinal part-sectional elevation showing the safety valve of Figs. 2A to 2D with the valve closure means open, o the lockout sleeve of the safety valve in its inoperative 0 0 position, and the shifting tool of Fig. 3 engaged Q0 therewith;' 04 0 0 Sa Figs. 6A, 6B and 6C taken together form a view similar to Figs. 5A, 5B and 5C showing the shifting tool 4o and the safety valve after shifting of the lockout sleeve o 15 to hold open the valve closure means; Figs. 7A, 7B and 7C taken together form a view similar to Figs. 6A to 6C showing the shifting tool released from the operator tube in the safety valve after I -7 shifting the lockout sleeve to hold open the valve closure means; Fig. 8 is a view similar to Figs. 7B and C showing the valve closure mneans temporarily locked open with the shifting tool removed; Figs. 9A and 9B taken together form a longitudinal. part-sectional elevation illustrating an alternative embodiment of the shifting tool; and Figs. 10A and 10B taken together form a longitudinal part-sectional elevation illustrating another alte-rnative embodiment of the shifting tool.

o 0 Referring firstly to Fig. 1, a well completion includes a casing string 28 extending fromi the well surface to a hydrocarbon producing formaation (not showan), a tubing string 21 is concentrically disposed within the c asing string 28 and extends from wellhead 23 through a production packer 22 which seals between the tubing string 21 and the casing 28. The packer 22 directs fluids, such as oil, gas, water or the like,A ntothetubngstring 21 frmperforations (not son in the casing 28, which per-forations admit formation fluids into the well bore. Flow control valves 24a and 24b at the well surface control fluid flow from the tubing 00 0 0 0 0 o 0 0 00o 00 0 Q040 00 0 0 0 040 0. 0 0 0 0 a' 0 0 0 0 0 000 0 00 00 0 0 0 0 0 ocan 0U 0 0000 00 a o 0 0 o>o au 0 S0 0 9 i 6 8 string 21. A wellhead cap 27 is provided on the wellhead 23 to permit servicing of the well 20 via the tubing string 21 by .wireline techniques which include the installation and removal of various flow control devices such as valves (not shown) from within the tubing string 21. Other well servicing operations which may be carried out through the tubing string 21 are bottom hole temperature and pressure surveys.

A surface controlled subsurface safety valve 10 embodying the features of the invention is installed in the well 20 as a part of the tubing string 21 to control fluid flow to the well surface via the tubing string 21 from a downhole location. The safety valve 30 is operated by control fluid conducted from a hydraulic 15 manifold 25 at the well surface via a control line conduit 26 which directs control fluid signals to the safety valve 30. The hydraulic manifold 25 generally includes pumps, a fluid reservoir, accumulators, and control valves (not shown in detail) for the purpose of providing 20 control fluid pressure signals for holding the safety valve 30 open or allowing this valve 30 to close when desired. The manifold 25 also includes apparatus which functions in response to temperature, surface line leaks, and other emergency conditions under which the well should be shut in.

-9- The safety valve 30 includes flapper type valve closure means 31 mounted by hinge 34 (see Fig. 2C) for swinging between a closed position schematically represented in Fig. 1 and an open position which permits fluid flow in tubing string 21. When a predetermined pressure signal is applied to the safety valve 30 through the control line 26 from the manifold 25, the valve closure means 31 is maintained in its first or open position. When the control pressure signal is released, the valve 30 is 0 allowed to move to its second or closed position. A Q 0lockout sleeve 50 is provided in the valve 30 for movement 00 between a first position which holds the valve closure 0 00 00 means or flapper 31 open and a second position in which the 0 °1 valve closure means or flapper 31 is free to open or close.

With the flapper 31 restrained open by the lockout sleeve 0 50, various well servicing operations may be conducted 0 o without fear of inadvertent closure of the valve 30 which can be damaging to the servicing equipment.

Details of the construction of the safety valve and the lockout sleeve 50 are shown in Figs. 2A to 2D. A shifting too]. 70 for operating the lockout sleeve 50 is illustrated in Figs. 3A and 3B and will also be described in detail. The subsurface safety valve 30 has housing means 60 formed by a top sub 61a, a bottom 1 1 1 t sub 61b, and interconnected housing subassemblies 62, 64, 65 and 66 which are suitably interconnected by threaded joints as illustrated. The housing means can be generally described as being a long thick-walled cylinder with a longitudinal bore 67 extending therethrough. The top and bottom subs 61a and 61b may be internally or externally threaded to provide means on opposite ends of the housing means 60 for connection with the tubing string 21 as represented in Fig. 1. The 10 top sub 61a includes locking grooves 68 machined on its inside diameter. The locking grooves 68 provide means for installing a secondary or retrievable safety valve (not shown) within the longitudinal bore 67 if the safety 4 a Svalve 30 should become inoperative. The secondary valve may be designed to operate in response to the same control signal as the safety valve 30 or may be designed to respond directly to changing well conditions.

4 t 1 The housing subassembly 62 has a threaded connection 29 to allow connection of the control line 26 to the safety valve 30. Control fluid pressure signals are communicated from the well surface via the control line 26, the threaded connection 29, a passageway 81, and j an opening 82 to the longitudinal bore 67. A cylinder 83 is positioned within the longitudinal bore 67 adjacent to the opening 82. During normal operation of the safety 114" 7Ii -11valve 30, control fluid pressure signals are directed to an operator tube 40 via an annular passageway 84 formed between the inside diameter of the housing subassembly 62 and the outside diameter of the cylinder 83.

A permanent lockout sleeve 80 is slidably disposed within the longitudinal bore 67. This permanent lockout sleeve 80 is sixed to fit concentrically within the cylinder 83. During normal operation of the safety valve 30, a knockout plug 85 holds the permanent lockout sleeve 80 in its inactive position shown in Fig. 2A. If the safety valve 30 should become inoperative, a profile I 86 on the inside diameter of the permanent lockout sleeve S° 80 can be engaged by a suitable shifting tool (not shown) to force the sleeve 80 into abutting contact with the 6604 S, 15 operator tube 40 and to open the safety valve 30. Move- 0'o. ment of the sleeve 80 causes the knockout plug 85 to shear, Sallowing communication fo control fluid pressure signals therethrough, A snap ring 87 is carried by the housing subassembly 62 within the longitudinal bore 67 to lock the sleeve 80 in place after it has moved. Matching teeth 88 are carried on the outside diameter of the sleeve .80 and the inside diameter of the snap ring 87. The use of locking grooves or recesses 68, the permanent locking sleeve 80, and associated components to instal a secondary safety valve within a bore, such as the longitudinal bcre 67, is well known in the art.

I i operator tube 40 is slidably disposed within the longitudinal bore 67 to shift the valve closure means 31 from its second, closed position to its first, open position as shown in Fig. 2C. For ease of mianufacture and assembly, the operator tube 40 is constructed from two generally hollow cylindrical subassemblies designated 40a ana 40b. These subassemblies 40a and 40b are joined together by a threaded connection 41. Movable piston seal means 42 is carried on the exterior of the operator tube 40 to form a sliding fluid barrier with the inside diameter of the housing subassembly 63 adjacent thereto. Stationary seal means 43 is carried by the cylinder 83 to form a fluid barrier with the 0 exterior of the operator tube 40. The stationary seal means 43, the movable piston seal means 42, and the exterior of the operator tube 40 therebetween define in 4 4 apart a variable volume control fluid chamber 48. Control fluid pressure from the annular passageway 84 is received 0 within the chamber 48 to act upon the piston seal means 42 and to slide the operator tube 40 longitudinally towards the valve closure means 31 in response thereto.

Biasing means in the form-, of a spring 44 is carried on the exterior of the operator tube 40 between a shoulder 64a on the inside diameter of the housing subassembly 64 and a shoulder-45 on the extearior of the operator tube This biasing means 44 applies a force tu shift t-he operator tube 40 longitudinally opposite from control 13 fluid pressure in the chamber 48. When control fluid pressure in the'chamber 48 is decreased below a preselected value, the spring 44 moves the operator tube longitudinally upwards to allow the valve closure means 31 to return to its closed.position. A spring 35 coiled around the hinge 34 also assists in moving the flapper 31 to its closed position.

A selective key profile 46 is formed on the interior of the operator tube 40 intermediate the ends thereof.

S 10 This profile 46 provides means for releasably engaging the operator tube 40 with a shifting tool whereby the shifting So, tool can move the operator tube 40 independently of the 0 Co. control signal. The use of shifting tools 70, 170, and 270 with respect to the profile 46 and the operator tube 15 40 will be described later in detail. The configuration and dimensions of the profile 46 are selected to be.

different from the locking recess 58 and the profile 86.

Therefore, the operator tube 40 can be engaged only by a 2 shifting tool having selective keys which the match profile 46.

The lockout sleeve 50 which is a second lockout sleeve, is slidably disposed in the housing means 60 in tandem with the operator tube 40. In comparison to first lockout sleeve 80, the second sleeve 50 can be classified as a temporary lockout device. This lockout sleeve L 14 has a first position, shown in Fig. 8, which holds the valve closure means 31 in its first position, and a second position, shown in Fig. 2D, which does not restrict movement of the valve closure means 31 between its first and second positbns. As shown in Figs. 2D and 8, the lockout sleeve 50 has a relatively smooth uniform inside diameter. Therefore, it is difficult for a wireline tool accidentally to engage the lockout sleeve and shift it to an undesired position. The smooth, 10 uniform inside diameter'of the lockout sleeve 50 is an 4 important preferably feature of the present invention.

0 4 0 o A plurality of longitudinal slots 51 are machined 09 44 a° 'through the sleeve 50 intermediate the ends thereof.

These slots 51 are circumferentially spaced to provide S0 4* 0 0 15 a plurality of collet fingers 52. An external boss 53 is provided on each collet finger 52. Internal grooves Qo.a 54 and 55 are provided on the interior of the housing subassembly 66 to receive the bosses 53 therein. The a, grooves 55 and 54 are spaced longitudinally from each other to correspond respectively with the first pqsition and second position .for the lockout sle.eve 50. The.

collet fingers 52, the bosses 53, and the grooves 54 and 55 cooperate to provide means for releasably holding the lockout sleeve 50 in its first or second position.

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15 Longitudinal movement of the lockout sleeve within the longitudinal bore 67 is limited by a shoulder 66a on the interior of the housing subassembly 66 contacting a shoulder 57 on the exterior of the sleeve 50 and by the sleeve 50 resting on a spacer ring 69.

As best shown in Fig. 2D, the inside diameter of the spacer ring 69 is larger than either the sleeve 50 or the bottom sub 61b of the housing. The spacer ring 69 is used to define a recess 58 in the housing means below the lockout sleeve 50. It will be explained later how the recess 58 is used to shift the lockout sleeve 0 00n o o to its first position.

0 0 0 0 0 0o 0 coo 0 000 u 0 The shifting tool 70, shown in figs. 3A and B, is 0 o0 0" used to shift"'he lockout sleeve 50 from its second to 0 o its first position. This shifting tool 70 is adapted Ooo for insertion into the longitudinal bore 67 by use of 11 00 o0" conventional wireline techniques. The shifting tool has an inner mandrel or core means 71 slidably disposed within cylindrical housing means 72. For ease of manufacture and assembly, the core means 71 comprises several subsections 71a, 71b and 71c. The subsections 71a and 71b are two generally solid cylindrical rods connected to each other by threads 73. A fishing neck: 74 is provided on the upper end of the subsection 71a which extends from housing means 72. This fishing neck 11- %A 4-NA--to pWAA JV i.Lt;.LUJ tAII(A t 16 hollow cylindrical subsections designated 72, 72b, and 72c which are attached to each other by appropriate threaded connections. During initial insertion of the shifting tool 70 into the longitudinal bore 67, a first releasable means, in the form of a shear pin 75, extends through both the core means 71 and the housing means 72, as shown in fig. 3A, to prevent undesired relative S° longitudinal movement therebetween, 0 00 0 0o A plurality of selective keys 76 are disposed O0 4 0 within windows 77 extending through the housing subsection oo A 72a. Leaf springs 78 are carried on the inside diameter of the subsection 72a adjacent to these selective keys 76. The springs 78 are designed to project the keys 76 radially outward through the windows 77. The core means 71 has a reduced diameter portion 91 which allows the keys 76 to be compressed radially inward by restrictions in either the tubing string 21 or the safety valve 30. The shear pin 75 is used to hold the reduced diameter portion 91 radially adjacent to the keys 76 during insertion of the tool 70. A plurality of bosses 92 are provided on the reduced diameter portion 91 adjacent to each key 76.

r irst means for releasably engaging the inner core means to

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,4 i The bosses 92 and the interiors of the keys 76 are designed to allow inward compression of the keys 76 when the shear pin 75 is installed.

The keys 76 each have an exterior profile which matches the profile 46 of the operator tube 40. Engagement of the kIys 76 with the profile 46 prevents further downward movement of the shifting tool 70 relative to the safety valve 30 due to the presence of square shoulders 93 and 94 (see Figs. 3A and 2B). Force can then be applied to the core means 71 to shear the pin 75 and ao a 0 0 slide the core means 71 longitudinally relative to the housing means 72. This longitudinal movement positions oa a the bosses 92 radially adjacent to and contactinrv a S 0 0 a. portion of their respective keys 76 to lock the keys 76 radially projected as shown in Fig. 0004 0 o a A second shear pin 95 is carried by the housing subsection 72a and is biased radially inwards by a leaf *t spring 96. The exterior of the core means 71 has an annular groove 97 formed on its exterior. The location of this annular groove 97 is selected so that the shear pin 75 will normally hold the groove 97 spaced longitudinally from the second shear pin 95. When the core means 71 moves relative to the housing means 72, the groove 97 is designed to be engaged by the second shear ro

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18 pin 95. The groove 97 and the shear pin 95 cooperate to provide, second releasable means for preventing undesired relative movement between the core means 71 and the housing means 72 to hold the keys 76 radially expanded.

The shifting tool 70 has a plurality of latching dogs 100 space longitudinally from the selective keys 76. These latching dogs 100 are slidably disposed within second windows 101 of the housing subsection 72c.

A leaf spring 102 is provided to project each dog 100 o radially outward. The inner core means section 71c has o a reduced diameter portion 103 which allows the dogs 100 to be compressed radially inward by restricting in the 4a Q0 tubing string 21 including portions of the safety valve o04 oO 30. The dogs 100 are specifically sized to fit within the recess 58 below the lockout sleeve 14 t The shear pin 75 normally holds the reduced diameter Sportion 103 radially adjacent to the dogs 100. When the pin 75 is sheared, the core means 71 can move longitudinally to position an enlarged outside diameter portion 104 of subsection 71c radially adjacent to the dogs 100.

The enlarged portion 104 prevents the dogs 100 from flexing radially inwards. The second shear pin 95 and the annular groove 97 cooperate to lock the dogs 100 radially expanded.

The hifing ool70 as aplualiy oflathin 4

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19 Ooeratinq sequence 00* 00 co 0 0 0 0 00 00 For purposes of describing the operation of this embodiment, it will be assumed that the safety valve is installed in a well completed as shown in Fig. 1 Control fluid pressure is communicated from the manifold 25 via the control line 26 to the housing means 60 of the safety valve 30. Using standard well servicing techniques and surface wireline equipment (not shown), the shifting tool 70 is introduced into the tubing string 21 via the wellhead cap 27.

10 In Figs. 5A, 5B, and 5C, the safety valve 30 is shown in its first position with control fluid pressure in the chamber 48 acting on the operator tube 40 to hold the flapper 31 open. A wireline tool string (not shown) would be attached to the fishing neck 74 to eanable the 15 shifting tool 70 to be manipulated within the longitudinal bore 67. The selective keys 76 are engaged with the profile 46 in the operator tube 40 to prevent further downward movement of the shifting tool 70 relative to the safety valve 30. This engagement allows force to be 20 applied to the fishing neck 74 by the wireline tool string to shear the pin 75 into two pieces 75a and 75b as shown in fig. 5A. The force applied to the fishing neck 74 causes the inner core means 71 to slide longitudinally downward until the fishing neck 74 rests on the top of the housingy means 72. This downward movement of the 00 O 4' O 000 44 0 0 0 0 C~r 20 core means 71 will position the bosses 92 behind their respective keys 76 and the enlarged outside diameter portion 104 behind the dogs 100. Leaf spring 96 will force the shear pin 95 into the annular recess 97 which locks the keys 76 and the latching dogs 100 in their radially expanded conditions.

With the safety valve 30 and the shifting tool positioned as shown in figs. 5A, 5B, and 5C, the next step towards temporarily locking open the safety valve 30 is to decrease control fluid pressure in the chamber 48 below a preselected value. Since the keys 76 are 0 9 0° locked into the profile 46 and the latching dogs 100 are 00 °locked outward into the recess 58, the operator tube o4 o0 and the lockout sleeve 50 must mvoe in unison. Force can be applied to the shifting tool 70 via the wireline attached to the fishing neck 74 to assist the spring 44 Sin shifting the operator tube 40 to its second position and the lockout sleeve 50 to its first position as shown in Figs. 6A, 6B, and 6C.

With the lockout sleeve 50 in its first position, additional upward force can be applied to the fishing neck 74 to shear the pin 95 into two pieces as indicated at 95a and 95b. The inner core means 71 is then free to move to its initial longitudinal position with respect to the housing means 72 which allows the keys 76 and the r.ua.as inco cne we.u. Dore. ri4ow coftro.L vajv ci 4aaiu 241a at the well surface control fluid flow from the tubing 21 latch dogs 100 to be compressed raially inwiard. Figs.

7A and 7B3 show the shifting tool 70 in this configuration while it is being withdrawn from the longitudinal bore 67.

The final result of these operations is shown in Fig. 8. The lockout sleeve 50 is in its first position holding the f lapper 31 open. The operator tube 40 has been returned to its second position. The shifting tool has been removed from the longitudinal bore 67. As previously noted, the smooth uniform inside diameter of 0 0 a the lockout sleeve 50 greatly reduces the possibility,.

of a wireline service tool or tools accidentally shifting the sleeve 50 and returning it to its second 0 aposition. When the desired well maintenance has been completed, the safety valve 30 can be returned to normal operation by simply applying control fluid pressure to to move to its first position. During this movement' 4 the operator tube 40 abuts the second lockout sleeve a~20 and returns such sleeve 50 to its second position.

During the initial installation of the tubing string 21 withing the casing 28, the lockout sleeve *can be used to check the integrity of the control line 26 and the proper functioning of the safety valve During installation, the safety valve 30 is preferably! and other emergency conditions under which the well should be shut in.

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22 attached to the tubing string 21 wihh the valve closure means 31 and the lockout sleeve 50 both in their first position. The collet fingers'52, the bosses 53 and the groove 55 are designed to allow a substantial amount of control fluid pressure to be applied to the chamber 48 before the operator tube 40 can shift the lockout sleeve to its second position. By applying less than this amount of pressure to the control line 26 from the manifold 25, the integrity of the control line 26 can be monitored. A drop in the control line pressure or a decrease in control fluid level at the manifold indicates a possible leak in the control line 26 which should be investigated before completing the well After the tubing string 21 is properly disposed within 9 9, 15 the casing 28, sufficient pressure can be applied to the control line 26 to shift the lockout sleeve 50 to its second position. Proper operation of the safety valve can be verified by monitoring the control line el pressure and volume required for this shifting.

A 20 Alternative Embodiments The above description has been directed towards an operator tube which opens a flapper type valve closure means. U.S. Patent 3,860,066 to Joseph L. Pearce el al demonstrates that the-operator tube 40 could be modified to open and close ball type and poppet type valve

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1 1! i means ov zoiimu vy t, UUP :JtAAJ U MLCIF CA i 23 closure means as alternatives to the flapper 31. The shifting tool 170 shown in Figs. 9A and 9B may be used to cycle any type of valve closure means between its open and closed position as long as the valve operator tube has been modified for releasable engagement with the tool 170.

Generally, the shifting tool 170 will be used to open the valve closure means. However, it could be usd to move the operator tube 40 to close the valve closure means if required.

Some components and features of the shifting tool 170 are identical to those of the shifting tool 70 and have S given the same (reference numerals). The principal structural differences between the shifting tool 170 and ao the above-identified shifting tool 70 are the replacement 0 0 S" 15 of the fishing neck 74 by an equalising valve and packing assembly 180 and rer val of the core means subsections 71b 0 and 71c and the housing means subsections 72b and 72c. The Sprincipal operating differences are that the equalising valve and packing assembly 180 allows fluid pressure in the tubing string 21 to be applied to the operator tube 40, and latching dogs 100 are not provided to shift the lockout sleeve r is Positioned within the longitudinal bore 67 adjacent to the opening 82. During normal operation of thle safety V 4 24 04 44 4 o 0 4 0 o 40 44 4 '44 04 44 44 o ago 44 44 04 4 4 4 49 44 4 0 4 4 4 o4&( 4 4 4 90 4 4 44 94

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4±4 The equalising valve and packing assembly 130 as shown in Fig. 9A includes a fishing neck 174 for attachment to a standard wireline tool string. This fishing neck 174 is connected by threads to a poppet valve plunger 181 which is slidably disposed in a valve housing '182. Ports 183 communicate fluid between the interior and exter,.or of the valve housing 182. A valve seat 184 is disposed within the valve housing 182 for engagement with the valve plunger 181.

A packing carrier 185 is attached to the valve housing 182 by threads 187. Packing or seal means 186 is carried on the extei ior of the packing carrier 185.

The dimensions of the seal means 186 are selected Co form a fluid barrier with the inside diameter of the 15 housing top sub 61a when the shifting tool 170 is engaged with the operator tube 40. A hollow longitudinal spacer 188 is used to attach the packing carrier 185 to the core means section 71a by suitable threaded connections. A longitudinal flow passageway 189 20 extends through the valve housing 182, the packing carrier 185 and the spacer 188. A Prot 190 communicates between the exterior of the spacer 1 88 and the longitudinal flow passageway 189.

During installation of the shifting tool 170, the plunge r 131 is spaced longitudinally above the valve 4 i tjieve UO, ancd asociated components to instal. a secondary safety valve withi~n a bore, such as the longitudinal bore 67, is well known in the art.

seat 184 to allow fluid in the tubing string 21 to bypass the seal means 186. When the keys 76 engage the profile 46, the plunger 181 is lowered to contact the valve seat 184 to block fluid flow via the longitudinal passageway 189. The length of the spacer 188 is preferably selected so that the seal means 186 form a fluid barrier with the inside diameter of housing bottom sub 61a immediately below the locking recesses 68. Hydraulic fluid pressure can then be applied fro~m the well surf ace via the tubing string 21 to act on the seal means 186. Since the effective piston area of 0000the seal means 186 is much larger than the piston seal means 42 carried by the operator tube 40, the shifting 000 tool 170 can apply considerably more force to the 00 00 0 15 operator tube 40 to cycle the valve closure means 31.

0 0 type valve closure means. Also, the spacer 188 could ~C>be removed if the operator tube 40 is modified to allow., teseal means 186 to form a fluid barrier therewith.

The shifting tool 170 is released from engagement with the operator tube 40 in the same manner as peviously described for the shifting tool 70. When suffEicient upward force is applied to the fishing neck 174 to shear the pin 95, the core means subsection 71a will move upwards to allow the keys to be compressed 26 radially inwards.

The above description has been directed towards a safety valve which is opened and closed in response to a hydraulic fluid control signal from the well surface. The present invention can be used in conjunction with any type of safety valve control signal including electrically operated valves such as shown in US Patent 3,731,742 to Phillip S Sizer et al or US Patent 4,002,202 to Louis B Paulos et al.

Another alternative embodiment of the present invention involves shifting tool 270 shown in Figs. 10A and and allows both the opening of a safety valve and locking the valve open, if desired, without regard to the *t presence of the valve's normal control signal. This ,15 embodiment is particularly important as a backup feature for safety valve control systems which use electrical, electronic, sound, electrohydraulic, hydraulic pilot or o 0 similarly sophisticated control systems. During periods when the sophisticated control systems are being repaired, the shifting tool 270 allows a safety valve having an operator tube with the profile 46 and the lockout sleeve to be temporarily locked open without regard to the precenrc of the normal control signal. A direct-acting safety valve would preferably be installed until repair of the

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tandem~ with the operator tube 4~U. Inl cowparl~.on to trsr, lockout sleeve 80f the second sleeve 50 can be classif~ied as a temporary lockout device. This lockout sl~eeve -27control system had been completed. Therefore, the present invention is not limited to use with hydraulically controlled safety valves and may in fact provide sufficient reliability to make more complicated control systems commercially acceptable for downhole safety valves.

In the event of a serious control line leak, it may not be desirable to use the permanent lockout sleeve to shift the valve closure means 31 to its first position because formation fluids can then escape via the 6ontrol line leak. The shifting tool 270 allows the valve closure means 31 to be locked open without the use of control fluid pressure and without disturbing the permanent lockout sleeve 80. A direct acting safety valve or STORM CHOKE (Registered Trade Mark) safety valve which does not require hydraulic control fluid can then be installed within the longitudinal bore 67 to maintain well safety. Prior to the p0 present invention, the only solution to a serious control A4 -~line leak was to remove the tubing string 21 from the well bore, which is a very expensive procedure.

The shifting tool 270 is substantially identical with the shifting tool 70, except that the fishing neck 74 has been replaced by the equalising valve and pack.ing assembly 180 of the shifting tool 170. The shifting tool 28 270 can use fluid pressure in the tubing string 21 to open the valve closure means 31 as previously described for the shifting tool 170. The shifting tool 270 can be manipulated by a wireline tool string attached to the fishing neck 174 to shift the lockout sleeve 50 to its first position as previously described for the shifting tool 170. The shifting tool 270 can be manipulated by a wireline tool string attached to the fishing neck 174 to shift the lockout sleeve 50 to its first position as previously described for the shifting tool The above description is illustrative of only some of the embodiments of the invention. Those skilled in the "o 0art will readily visualise other changes and modifications 0°o'o that may be made without departing from the scope of the 015 invention.

i i t_

Claims (6)

1. sleeve o 4r 0r 0 00 0 o 0 *00 00~o 0o 0 o 0 A shifting tool for use in operating a lockout of a well safety valve comprising: a. inner core means slidably disposed within a housing means; b. means for attaching one end of the inner core means to a wireline tool string; c. first means for releasably engaging the inner core means to the housing means to prevent relative movement therebetween; d. selective profile keys projecting radially through first windows in the housing means; e. latch dogs projecting radially through second windows in the housing means and spaced longitudinally from the selective keys; f. A--first releasable means holding the inner core means in it4 first position which allows compression of the selective keys and latch dogs radially inward; and g. second means for releasably engaging the inner core means to the housing means and holding both the selective keys .and the latch dogs radially expanded. A shifting tool for use in operating a lockout of a well safety valve, comprising: 406 0&

2. sleeve i i *i j Y means 71 moves relative to the housing means 72, the groove 97 is designed to be engaged by the second shear '1: 30 a. inner core means slidably disposed within a housing means; b. means for attaching one end of the inner core means to a wireline tool string; c. first means for releasably engaging the inner core means to the housing means to prevent relative movement therebetween; d. selective profile keys projecting radially through first windows in the housing means; e. the first releasable means holding the inner core means in a first position which allows compression of the selective keys radially inward; and f. second means for releasably engaging the inner core means to the housing means to hold the selective keys radially expanded for the displacement of the lockout sleeve with the tool.

3. A shifting tool according to claim 2 further comprising latch dogs projecting radially through second windows in the housing means and spaced longitudinally from the selective keys, said first and second releasable engagement means also respectively allowing compression of the latch dogs radially inwards and holding the latch dogs radially expanded.

4. A shifting tool according to claim 1 or 3 wherein the latch dogs are sized to abut the lower end of the lockout sleeve when the selective keys are engaged with an o 0 900 0 9 0 0 p~ 0 o 0 0 a 0 1 i 11 J 31 operator tube for displacing the safety valve to an open position, the shifting tool thereby providing means for moving the lockout sleeve in unison with the operator tube.

A shifting tool according to any one of claims 1 to 4 wherein peripheral sealing means are carried on the exterior of the tool to form a fluid barrier for the safety valve whereby fluid pressure can be applied to the tool remotely to open the valve closure means.

6. A shifting tool according to claim 5 arranged to cycle an operator tube of the safety valve by said application of fluid pressure, without releasing said first releasable engagement means. CA7. A shifting tool substantially as hereinbefore 0 described with reference to the accompanying drawings. a Dated this TWENTY NINTH day of JANUARY 1991.q 04 CA OTIS ENGINGEERING CORPORATION Aplcn WRAY ASSOCIATES, Patent Attorneys for the Applicant. ABSTRACT SURFACE CON4TROLLED SUBSUR'ACE SAFETY VALVE A surface controlled subsurface safety valve for use in a well tubing string includes a valve closure member 31, an operator tube 40 for opening the valve closure member 31 and holding it open, an annular piston 42 on the operator tube 40 operative in response to control fluid pressure conducted from the well sur-face, a spring 44 biasing the operator tube 40 to a position at 4 which the valve 31 is closed, and a lockout sleeve 0 4 G 4 mounted in tandem with the operator tube 40 for movement 0 00 0 10 sirulraneously with the operator tube 40 to a position at which the lock-out sleeve 50 holds the valve 31 open. The operator tube 40 and lockout sleeve 50 are engageable by a shifting tool 70, to operate the operator tube 4 and lockout sleeve 50 simultaneously. The lockout sleeve 50 can be returned to an inoperative position by control fluid pressure moving the operator tube 40 to a position which opens the valve closure member 31. The safety valve is also operable by *a modified shifting tool engag- ing the operator tube. The shifting tool includes select- simultaneous coupling of the operator tube 40 and the lockout sleeve