GB2351310A - Tubing hanger and tree with horizontal flow and annulus ports - Google Patents

Abstract

A well production assembly comprises a production tree having a vertical axis, an axially extending bore and a lateral production passage extending from the bore through a sidewall of the tree transverse to the vertical axis. A generally upward facing shoulder is formed in the bore. A tree auxiliary passage extends through the sidewall of the tree and has an auxiliary connector at the upward facing shoulder. A tubing hanger lands sealingly in the bore and is connected to a string of tubing which extends into a well. The tubing hanger has a lateral production passage which extends from an axial production passage and aligns with the lateral production passage of the tree. A tubing hanger auxiliary passage extends through the tubing hanger and has an auxiliary connector which mates with the auxiliary connector in the tree when the tubing hanger lands, to communicate the tree auxiliary passage with the tubing hanger auxiliary passage.

Description

2351310 2 3 4 TUBING EANGER AND TREE WITH HORIZONTAL FLOW 6 AM ANNULUS

PORTS 7 Inventor: Philippe Nobileau 21 This invention relates in general towellhead 12 equipment, and in particular to a production tree having 13 a tubing hanger therein, the tubing hanger and production 14 tree having lateral production passages.

16 BACKGROMM AR7! 17 A conventional subsea wellhead assembly includev7a is wellhead housing which supports one or more casing 19 hangers located at upper ends of strings of casing extending into the well. A tubing hanger lands in the 21 wellhead housing above the casing hanger and supports a 22 string of production tubing that extends through the 23 smallest diameter casing. The tubing hanger has a 24 production bore which is offset slightly from the longitudinal axis. An annulus bore also extends through 26 the tubing hanger, parallel to and offset from the axis, 27 for communicating the tubing annulus to above the tubing 1 hanger. The annulus bore is needed during installation 2 of the tubing hanger and tubing to establish circulation 3 down the tubing and back up the annulus. After the well 4 has been completed, a removable plug is installed in the annulus bore, then a production tree is mounted to the 6 wellhead housing. Access through the production tree to 7 the tubing may be made for various workover operations 8 that are needed.

9 In the last few years, operators have begun installing a different type of wellhead ass emb ly, 11 referred to generally as a horizontal tree. In a 12 horizontal tree, the tubing hanger lands in the tree, not 13 in the wellhead housing located below the tree. The 14 tubing hanger has a lateral flow passage extending from is its vertical f low passage. The lateral f low passage 16 registers with a lateral flow passage extending through 17 a sidewall of the tree. Gallery seals are employed to 18 seal the junction between the lateral production 19 passages. The gallery seals comprise seal rings which are coaxial with the vertical axis, with one of the seals 21 located above the lateral passage and the other located 22 below. The lower seal necessarily will be of a smaller 23 diameter than the upper seal in order to provide 1 clearances f or installation.

2 With the horizontal tree, a tubing hanger can be 3 pulled through the horizontal tree without removing the 4 tree. This cannot be done with a conventional tree.

While this is an advantage, one disadvantage is the 6 horizontal tree tubing hanger has inadequate room to 7 utilize a vertical annulus passage extending through the a tubing hanger as with a conventional tubing hanger.

9 Instead, tubing annulus communication is accomplished generally by utilizing a bypass passage through the tree 11 from below the tubing hanger and back into the tree above 12 the tubing hanger. While a bypass passage is workable, -13 it relies on a valve on the exterior for closing the 14 annulus. Some-operators believe that a removable plxg is installed within an annulus passage in a tubing hanger is 16 safer than a valve.

17 Another disadvantage of a typical horizontal tree 18 tubing hanger has to do with the need to communicate 19 auxiliary fluid to downhole equipment. For example, downhole safety valves are used in a tubing string at 21 some distance below the surface. A safety valve remains 22 open so long as it is supplied with hydraulic fluid 23 pressure. In the absence of f luid pressure, it will I close. Consequently, if the production wellhead assembly 2 is severely damaged, the well would be held under control 3 through the safety valve. In conventional tree tubing 4 hangers, passages are drilled through the tubing hanger from the upper end to the lower end. The upper ends of 6 the hydraulic passages have connectors which matewith 7 connectors on the tree to supply hydraulic fluid. in the 8 horizontal tree, however, this cannot occur because the 9 tubing hanger lands within the tree, not in the wellhead housing below.

11 Some manufacturers have drilled ports through the 12 sidewall of the tree to communicate with hydraulic 13 passages drilled within the tubing hanger. These 14 manufacturers have employed gallery type seals to seal the junctions of the ports. This again requires a 16 reduction in inner diameter of the bore of the tree.

17 There may be several ports for auxiallary fluid passages, is requiring several sets of gallery seals. U.S. Patents 19 5,465,794 and 5,555,935 show ports on the exterior of a tubing hanger that do not requires gallery seals. These 21 ports locate on a spherical surface formed on the tubing 22 hanger and in the bore of the tree.

23 According to the present invention there is provided a well production assembly comprising in combination: a production tree having a vertical axis, an axially extending bore, and a lateral production passage extending from the bore through a sidewall of the tree transverse to the vertical axis; generally upward facing shoulder formed in the bore; tree auxiliary passage extending through the sidewall of the tree and having an auxiliary connector located at the upward facing shoulder; a string of tubing extending into a well; a tubing hanger which lands sealingly in the bore and is connected to the string of tubing, the tubing hanger having a lateral production passage extending from an axial production passage, the lateral production passage aligning with the lateral production passage of the tree; and a tubing hanger auxiliary passage extending through the tubing hanger, having an auxiliary connector which telescopingly and sealingly mates with the auxiliary connector in the tree when the tubing hanger lands, to communicate the tree auxiliary passage with the tubing hanger auxiliary passage.

BRIE? Dmoal"-10N or M:HZ DRAWINGS Figurbs IA and 1B comprise a vertiral sectional view of a wellhead assembly constructed in accordance with this invention.

Figure 2 is an enlarged partial sectional view of a portion of the wellhead assembly of Figures 1A, IB.

Figure 3 is a sectional view of a portion of the wellhead assembly of Figwes IA, IB, taken along the line 3-3 of Figure 2, with the left '.side showing an installation stop and the right side showing the assembly after installation has been completed.

Figure 4 is a sectional view of the wellhead assembly of Figures IA, 1B, taken along the line 4-4 Of Figure 1.

I DETAT LED DESPRIPTION OF- THE PREFMED IMODIMENT 2 Referring to Figure 1B, a subsea wellhead is shown, 3 including a tubular low pressure housing 11 that lands in 4 a guide base 13 supported on the sea f loor. Housing 11 is connected to a large diameter conductor extending into 6 the well to a f irst depth. A high pressure housing 15 7 lands in the low pressure housing 11. High pressure a housing 15 is also a tubular member, and it is secured to 9 a string of casing 17 which extends into the well to a second depth. A lower casing hanger 3-9 lands in wellhead 11 housing 15 and supports a string of casing 21 which 12 extends into the well to a third depth. An upper casing 13 hanger 23 lands on top of lower casing hanger 19 and 14 supports a string of casing 25 which extends to the is bottom of the well in the embodiment shown. Both casing 16 hangers 19, 23 are conventionally sealed to the bore of 17 high pressure housing 15.

18 A lower tubing hanger 27 lands in the bowl of the 19 upper casing hanger 23. Lower tubing hanger 27 is secured to a string of production tubing 29 which extends 21 into the well f or providing a conduit f or the f low of 22 production f luid. Lower tubing hanger 27 has a vertical 23 production passage 31 which is coaxial with tubing 29.

I An annulus passage 33 is also axial o'r Vertical, and 2 extends alongside production passage 31. Annulus passage 3 33 is in communication with an annulus space surrounding 4 tubing 29.

Lower tubing hanger 27 is secured conventionally in 6 upper casing hanger 23 by means of a cam sleeve 35, lock 7 ring 37, and actuating sleeve 39. Actuating sleeve 39 8 extends upward above the upper end of lower tubing hanger 9 27, as shown in Figure IB, and can be shifted by a running tool between an upper released position and a 11 lower locked position. A downhole safety valve 38 is 12 located in tubing 29 some distance below wellhead housing 13 11. Safety valve 38 is connected to a hydraulic line 40 14 which extends upward to lower tubing hanger 27.

is Hydraulic pressure in line 40 maintains safety valve 38 16 in an open position. The absence of hydraulic pressure 17 in line 40 causes safety valve 38 to close.

is Referring also to Figure IA, a'christmas tree 41 19 lands on top of wellhead housing 15. A conventional hydraulic connector 43 carried by tree 41 connects tree 21 41 to a grooved profile 45 formed on housing 15 near its 22 upper end. Tree 41 is a large tubular member that has a 23 grooved prof ile 47 on its upper end that is identical to I wellhead profile 45. Tree 41 has a production passage 49 2 that is horizontal, perpendicular to the longitudinal 3 axis, and extends from its bore 48 to the exterior. A 4 production master valve 51 controls the flow of production fluid out tree horizontal passage 49. Tree 41 6 also has an annulus passage 53 that is horizontal and 7 perpendicular to the vertical axis. In the embodiment a shown, it is located 180 degrees from and is coaxial with 9 horizontal passage 49. Tree annulus passage 53 also extends from the tree bore 48 to the exterior. An 11 annulus valve 55 can be controlled from the surface for 22 opening and closing annulus passage 53.

-13 Tree 41 is installed by lowering it on guidelines 14 attached to guide posts (not shown) of guide base 13 in is a conventional manner. As shown in Figure 2, tree 41 has 16 an orientation sleeve 56 mounted to it that extends 17 around actuating sleeve 39 of lower tubing hanger 27. A is key 58 on the exterior of lower tubing hanger 27 engages it a slat in orientation sleeve 56. Orientation sleeve 39 orients lower tubing hanger 27 if tubing hanger 27 is 21 being installed after tree 41 has already been installed.

22 If lower tubing hanger 27 is installed before tree 41 is 23 installed, it will be oriented by a conventional method 1 using an orientation internal groove on the BOP stack 2 wellhead connector.

3 Referring again to Figure IA, an upper tubing hanger 4 57 is supported in the bore of tree 41. Upper tubing hanger 57 has a vertical bore 59 that extends through it 6 offset from and parallel to the longitudinal axis of tree 7 41. A lateral passage 61 extends horizontally outward a from vertical bore 59 perpendicular to the vertical axis.

9 A seat ring 63 is mounted in a counterbore in tree horizontal production passage 49 at the junction with 11 tree bore 48. Seat ring 63 is sealed to passage 49 and 12 has a hole through it that is the same diameter as 13 passage 49. Seat ring 63 has an inner face 63a that is 14 flat but inclined relative to the axis of tree 41. The is upper edge of inner face 63a is f arther from the axis of 16 tree 41 than its lower edge. Seat ring 63 is sealed to 17 passage 49 but is removable. Upper tubing hanger 57 has is a mating seat ring 65 with a f lat inclined outer face 19 that is located at the outer end of lateral passage 61.

Seat ring 65 seals against flat face 63a of seat ring 63 21 in metal-to-metal sealing engagement.

22 Similarly, upper tubing hanger 57 has an annulus 23 vertical bore 67 which extends completely through upper 1 tubing hanger 57 off set from and perpendicular to 2 vertical bore 59. An annulus passage 69extends 3 horizontally from vertical bore 67. A seat ring 71 4 locates sealingly in a counterbore formed in tree annulus passage 53 at the junction with tree bore 48. Seat ring 6 71 is constructed the_ same as seat ring 63, except that 7 its hole is smaller because the tree annulus passage 53 8 is smaller in diameter than the production passage 49.

9 Upper tubing hanger 57 has a seat ring 72 that sealingly mates with the flat inclined face of seat ring 71.

11 A crown plug 73 of a conventional wireline 12 retrievable type is installed in upper tubing hanger -13 vertical bore 59. Crown plug 73 is located above 14 horizontal passages 61, 49. An annulus plug 75, also is wireline retrievable, is located in annulus vertical bore 16 67.

17 Referring to Figure 2, a production isolation sleeve 18 77 is sealingly secured to the lower end of upper tubing 19 hanger vertical production bore 59. Sleeve 77 extends sealingly into lower tubing hanger bore 31. An annulus 21 isolation sleeve 79 secures sealingly to upper tubing 22 hanger annulus bore 67. Annulus isolation sleeve 79 23 extends sealingly into lower tubing hanger annulus I passage 33. Upper tubing hanger 57 has an orientation 2 key 81, shown in Figure 2, that engages orientation 3 sleeve 56 of tree 41. This orients upper tubing hanger 4 57 relative to tree 41.

Referring to Figure 3, a plurality of hydraulic 6 fittings or connectors 83 are mounted to lower tubing 7 hanger 27 and face upwardly. Hydraulic connectors 83 a connect to hydraulic lines 40 (Fig. IB) for opening and 9 closing downhole safety valves 36 (Figure IB) - Female hydraulic fittings or connectors 83 are secur ed to the 11 lower end of upper tubing -hanger 57. Hydraulic 12 connectors 85 will stab over hydraulic connectors 83 to 13 make up a connection. Belleville springs 87 provide a 14 positive pressure to retain the connection. Similarly, is hydraulic connectors 89 are located on an upward facing 16 shoulder 90 in bore 48 of tree 41 outside of where upper 17 tubing hanger 57 will land. Downward facing female is hydraulic connectors 91 are mounted to upper tubing 19 hanger 57 to stab onto hydraulic connectors 89 when upper tubing hanger 57 is installed. Hydraulic connectors 89 21 are connected to paLssages which lead to a source of 22 hydraulic fluid pressure for opening safety valve 38 23 (Fig. IB) or performing other auxiliary functions.

1 Connectors 89 are also shown in Figure 4.

2 Referring to Figure 3, upper tubing hanger 57 is 3 secured in tree bore 48 by a lock member 93 which is 4 pushed outward by a cam member 95. The left side of Figure 3 shows upper tubing hanger 57 prior to insulation 6 while the right side shows upper tubing hanger 57 after 7 it is completely installed.

8 Referring again to Figure 1A, an internal tree cap 9 97 locates within tree bore 48 above upper tubing hanger 57. Internal tree cap 97 has two vertical bores 98, 100 11 which align coaxially with the upper tubing hanger bores 12 59, 67. Wireline retrievable plugs 99, 101 are located -13 within the bores 98, 100. A corrosion cap 103 is 14 installed over the upper end of tree 41 for protection.

=z ' is Referring to Figure 4, lateral annulus passage 53 leads 16 to a crossover passage 105 which will selectively connect 17 annulus passage 53 with the production passage 49.

18 Valves 107 will control opening and closing of crossover 19 passage 105.

In one Taode of operation, after the well has been 21 drilled and the casing hangers 19, 23 and lower tubing 22 hanger 27 oriented and installed, the operator can run 23 christmas tree 41 and secure it by connector 43. The 1 operator then installs upper tubing hanger 57, which 2 orients by means of its key 81 (Fig. 2) engaging tree 3 orientation sleeve 56. After testing procedures, the 4 operator installs wireline retrieval plugs 73, 75, internal tree cap 97, and wireline retrievable plugs 99, 6 101. The production fluid will flow-Up production tubing 7 29 and out horizontal passage 49.

a Several workover options are available. In one 9 mode, a drilling riser having a blowout preventer (not shown) will land on tree profile 47 after removing 11 corrosion cap 103. The internal tree cap 97 is removed 12 through the drilling riser using a recovery string 13 extending through the riser. Closing the downhole safety 14 valves (not shown) allows one to remove the wireline is plugs 73, 75. An adapter on the recovery string stabs 16 into the vertical production bore 59 while the annulus 17 vertical bore 67 communicates with the drilling riser is annulus around the recovery string and thus with the 19 riser choke and kill lines once the blowout preventer is closed around the recovery string. one conduit leading 21 to the production tubing 29 and one to the annulus space 22 is then established with the workover vessel.

1 Prior to removing tubing 29, the well ordinarily 2 must be killed. During this procedure, the well 3 production fluid is replaced with a heavier fluid. The 4 operator can kill the well by opening the downhole safety valve, and pumping down the recovery string and 6-- production tubing 29. The fluid flows out a port at the 7 lower end of the production tubing 29, back up the tubing a annulus, upper tubing hanger annulus bore 67, and up one 9 of the choke and kill lines.

After the well is killed, the operator can retrieve 11 production tubing 29 with the recovery string by pulling 12 upper tubing hanger 57, then pulling tubing hanger 27 -13 along with tubing 29. After the workover operation, 14 tubing 29 and lower tubing hanger 27 are lowered through is tree 41 and re-installed. Lower tubing hanger 27 Will 16 orient by engagement of key 58 with orientation sleeve 56 17 (Fig. 2) during the installation. Alternately, the 18 operator may remove tree 41 without pulling tubing 29.

19 In this instance, preferably another wireline plug (not shown) will be installed in a grooved profile in lower 21 tubing hanger 27 before removing tree 41. When tree 41 22 is pulled upward, upper tubing hanger 57 and isolation 23 sleeve 77 will be pulled with tree 41, while tubing I hanger 27 and tubing 29 remain in place.

2 Further, the well may be killed in other manners 3 than described above. Because of the two vertical bores 4 59 and 67 in upper tubing hanger 57, another method of killing involves stabbing a completion riser, which has 6 two strings side by side, into these bores after removal 7 of 'the internal tree cap 97 and plugs 73, 75. Also, a killing of the well can be accomplished by use of the 9 lateral annulus passage 69 and its crossover passage 105 10' (Figure 4). In this situation, there will be no annulus 11 conduit back to the vessel. Rather, after communication 12 is established between the tubing hanger vertical passage 13 59 and the vessel, production master valve 51 is closed 14 and annulus valves 55 and 107 (Fig. 4) are opened. Kill is f luid is pumped down the production tubing 29, through a is port (not shown) at the lower end and back up the tubing 17 annulus. The return fluid flows out annulus horizontal is passage 53, through crossover passage 105 and out the 19 production line downstream of production master valve 51.

The wireline retrievable plugs 73 and 99 allow 21 various wireline intervention operations without 22 retrieving either tubing hanger 27, 57 or internal tree 23 cap 97. During a wireline intervention when the well is 1 not to be killed, downhole safety valve for tubing 29 2 will be closed to allow wireline plugs 99, 73 to be 3 removed. The wireline, tool will be lowered through a 4 wireline riser which will be capable of withstanding the pressure of the well. The wireline riser comprises a 6 wireline BOP stack mounted to tree 41 to control the well 7 pressure. After the wireline tool has been lowered into 8 tubing 29, the downhole safety valve is opened, allowing 9 the wireline tool to pass through tubing 29.

The invention has significant advantages. Utilizing 11 a f lat seal area on the tubing hanger and in the bore of 12 the tree avoids the need f or gallery seals around the 13 mating lateral passages. This allows a larger diameter 14 tubing hanger for a particular tree bore than in the -Z - is prior art. The larger diameter tubing hanger enables a

16 vertical annulus passage to be drilled therein, which nay 17 be closed with a removable plug rather than a valve as in 18 the prior art. The hydraulic connectors which mate when

19 the tubing hanger lands also avoids the need f or gallery seals.

21 It should be understood that variations to the 22 embodiment may be made. For example, lower tubing hanger 23 27 may be eliminated. In that instance, upper tubing 1 hanger 57 would connect directly to production tubing 29.

2 It would not be possible to remove tree 41 without f irst 3 pulling tubing 29, but it would be possible to pull 4 tubing 29 without retrieving first the tree 41.

t, -is- CLA= 1 A well production assembly comprising in combination: a production tree having a vertical axis, an axially extending bore, and a lateral production passage extending from the bore through a sidewall of the tree transverse to the vertical axis; a generally upward facing shoulder formed in the bore; a tree auxiliary passage extending through the sidewall of the tree and having an auxiliary connector located at the upward facing shoulder; a string of tubing extending into a well; a tubing hanger which lands sealingly in the bore and is connected to the string of tubing, the tubing hanger having a lateral production passage extending from an axial production passage, the lateral production passage aligning with the lateral production passage of the tree; and a tubing hanger auxiliary passage extending through the tubing hanger, having an auxiliary connector which telescopingly and sealingly mates with the auxiliary connector in the tree when the tubing hanger lands, to communicate the tree auxiliary passage with the tubing hanger auxiliary passage.

2. The well production assembly according to claim 1, wherein each of the auxiliary connectors has an axis, and wherein the axes of the auxiliary connectors coincide when mated.

3. The well production assembly according to claim 1, wherein: - 19- the auxiliary connector of the tree is a tubular member which protrudes upward from the upward facing shoulder; and the auxiliary connector of the tubing hanger is a tubular member which protrudes downward from the tubing hanger.

4. The well production assembly according to claim 1, wherein: the auxiliary connector of the tree is a tubular member which protrudes upward from the upward facing shoulder; and the auxiliary connector of the tubing hanger is a tubular receptacle which protrudes downward from the tubing hanger and slides over the auxiliary connector.

5. The well production assembly according to claim 1, further comprising: a downhole safety valve connected into the tubing string for selectively interrupting fluid flow through the tubing string; and a hydraulic line extending from the downhole safety valve to the tubing hanger auxiliary passage for receiving hydraulic fluid pressure from the tree auxiliary passage to actuate the downhole safety valve.

6. The well production assembly according to claim 1, wherein the auxiliary connectors of the production tree and the tubing hanger are parallel to the vertical axis.