Source: https://patents.google.com/patent/US20070074870A1/en
Timestamp: 2020-06-04 14:30:41
Document Index: 619325490

Matched Legal Cases: ['art 39', 'art 40', 'art 41', 'art 41', 'art 40', 'art 40', 'art 39', 'art 51', 'art 51', 'art 51', 'art 5']

US20070074870A1 - Dual-type plug for wellhead - Google Patents
Dual-type plug for wellhead Download PDF
US20070074870A1
US20070074870A1 US10/557,435 US55743504A US2007074870A1 US 20070074870 A1 US20070074870 A1 US 20070074870A1 US 55743504 A US55743504 A US 55743504A US 2007074870 A1 US2007074870 A1 US 2007074870A1
US10/557,435
US7654329B2 (en
Hans Lindland
Stein Folkner
2003-05-22 Priority to NO20032330 priority Critical
2003-05-22 Priority to NO20032330A priority patent/NO322829B1/en
2004-05-19 Application filed by FMC Kongsberg Subsea AS filed Critical FMC Kongsberg Subsea AS
2004-05-19 Priority to PCT/NO2004/000151 priority patent/WO2004104364A1/en
2006-10-10 Assigned to FMC KONGSBERG SUBSEA AS reassignment FMC KONGSBERG SUBSEA AS ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FOLKNER, STEIN, LINDLAND, HANS JORGEN
2007-04-05 Publication of US20070074870A1 publication Critical patent/US20070074870A1/en
2010-02-02 Publication of US7654329B2 publication Critical patent/US7654329B2/en
241000191291 Abies alba Species 0.000 claims description 20
In a horizontal type Christmas tree the production tubing hanger is located within the tree and having a horizontal passage aligned with the horizontal production outlet in the tree. The production control valves are located in the horizontal outlet. The tubing hanger passage extends above the production outlet to gain access to the well and this passage must be closed off during production.
In a conventional Christmas tree, the tubing hanger is se in the wellhead and the production control valves are located in the vertical passage of the tree. The control valves function as barriers during normal production and the tubing hanger includes means for setting a plug in case the well must be closed down.
In recent years larger type's completion has become the norm, with tubing sizes up to 9″. The size of the intervention equipment has therefore also grown bigger, since the internal diameter of the pressure control valves and workover riser must be large enough to pull the correspondingly sized plug(s) through. At the same time, intervention tools have become smaller, down to perhaps 2″ or less. Therefore the need for pulling the plug(s) limits the scaling down of the equipment. This means that smaller equipment cannot be employed even if only small size tools are needed for the work in the well. For example, a standard type completion has a 6″ tubing and therefore a 6″ plug. The equipment must therefore be dimensioned with a nominal 6″ bore even if the tool to be used is only 2″ and could be run in on cable or wireline.
The plug according to the invention comprises a cylindrical housing, which may be adapted to the bore where the plug is going to be set. It further comprises releasable locking devises for holding the plug in fixed relations to the bore, and sealing devises. The sealing devises may be a part of the main cylindrical houses or separate elements hold in position by the plug. The sort of sealing devises necessary will depend on the working environment for the plug, like pressure, temperature, corrosivity etc.
By the plug according to the invention there is in the main cylindrical housing at, least one bore comprising at least one inner separate retrievable plug. The inner plug is preferably arranged coaxially with the outer main plug. Alternatively it may be arranged asymmetrically in relation with the main plug. There may also be more than one inner separate retrievable plug, for instance two arranged coaxially within each other.
The plug may comprise locking devises that cooperate with grooves in the bore where it is supposed to be set, this may also be the case for the inner plug by shaping the bore in the main cylindrical housing so that is corresponds with the locking devises for the inner plug.
FIG. 2 is a: vertical section through a plug according to the invention, and
FIG. 3 is a schematic drawing showing various intervention methods.
In FIG. 1 there is shown a Christmas tree of a type that is well known in the art. This is meant for illustration purposes only and it should be understood that many types of Christmas trees with various configurations and designs exist and can be used with the invention. Therefore only the main components relating to the invention will be described, since such design must be considered well known for persons skilled in the art.
FIG. 2 shows a plug 30 according to the invention. The plug is a sliding fit within bore 7 in the tubing hanger. The plugs 30 main housing includes outer cylindrical housing 31 and inner cylindrical housing 33, the inner housing being of shorter length than the outer part. The outer and inner cylindrical housing defines between them an annular space. The sealing devise in the form of a seal 43 is located around the outer surface of the plug 30, to seal between plug 30 and bore 7 when the plug is set. Outer housing 31 has a number of regular spaced openings 42 radially through its wall. In the openings are located the locking devises, in this embodiment in the form of locking dogs 41 that are held in a normally retracted position but can be made to extend radially to interface with a groove (not shown) in the tubing hanger bore 7. The inner wall of outer housing 31 has an upwardly facing shoulder 32. Inner wall of outer housing 31 is, along part of its upper end, machined out to form a circumferential slot 37.
A locking sleeve 35 is mounted for axial movement in the plug in annular space between outer 31 and inner 33 cylindrical housing. A downward facing shoulder 34 on the sleeve engages with shoulder 32 to act as a stop. Shoulder 34 divides locking sleeve in a lower part 39, middle part 40 with a greater outer diameter and upper part 41. Upper part has an inward facing flange 36. Also in upper part 41 but in the outer surface, a radial groove is machined out and a ring 38 located in the groove. The ring 38 protrudes outwards from locking sleeve to slide in slot 37. This, together with shoulder 34 acts as a limit for upward and downward movement of locking sleeve 35.
When locking sleeve is in its lower position as shown in FIG. 2 the middle part 40 pushes the locking dogs 41 outwards to engage with a ring groove in tubing hanger bore 7. Using a suitable tool to engage with flange 36, the locking sleeve can be pulled upwards. Locking dogs 41 will move out of engagement with middle part 40 and into engagement with lower part 39. The locking dogs 41 are now free to move into their retracted position. The plug 10 can now be pulled out from engagement with the tubing hanger bore 7.
An inner plug 50 is shown position co-axially within plug 30. Inner plug 50 is cup-shaped, with cylindrical part 51 and bottom 52. Inner plug 50 is a sliding fit within plug 30. Cylindrical part 51 has an outer wall with a downward facing shoulder 57 and regular spaced radial openings 62. The inner wall of cylindrical part 51 has an upward facing shoulder 55. At its upper end there is machined out a slot 56 of the same construction as slot 37. At the lower end of the plug are located seals 63 to seal against the surface 44 of plug 30. Locking dogs 53 are located in openings 62 and are held in a normally retracted position but can be made to extend radially to interface with groove 46 in inner wall of plug 30. A locking sleeve 54 is mounted within cylindrical part 5 1. Locking sleeve has a downward facing shoulder 60 that abuts against shoulder 55. At its upper end locking sleeve 54 has an inward facing flange 58. At its upper end is a circumference groove in which a ring 59 is mounted. The ring 59 slides in slot 56 to limit the locking sleeves axial movement. The locking sleeve 54 is thus movable between a lower position (as shown in FIG. 2) with shoulder 55 acting as a stop, and an upper position (not shown). When locking sleeve 54 is in the position shown in FIG. 2, the sleeve will force the dogs 53 outwardly into engagement with groove 46. The inner plug 50 is now locked within plug 30. Using a suitable tool acing on flange 36, the locking sleeve can be moved upwards to allow locking dogs 53 to retract and go out of engagement with groove 46. The inner plug is now unlocked from plug 30 and can be retrieved.
Three types of vessels are shown, a full drilling or intervention rig 70, an intermediate boat-type vessel 71 and a relatively small boat 72. The rig is used for heavy intervention type work, having full facilities for all type of intervention work and would include a tower hoist system, heave compensation system, storage space for risers, drillpipe and blowout preventers (BOP) and so on. The intermediate vessel 71 may also be equipped with tower hoist systems capable of running drillpipe but will normally be used for coil tubing operations and smaller workover risers or wireline work, and do not have the large handling capacity of the rig. This type of vessels is normally held in position with dynamic positioning (DP) systems.
The small vessel 72 have limited handling capacity and are therefore restricted in the type of work and in what weather conditions it can be used and will normally only be used to run equipment on wireline, cable or slickline. This type of vessel are only equipped with cranes.
Three types of intervention are also illustrated. The equipment shown can be connected to a Christmas tree that can either be a conventional 73 or horizontal 74 Christmas tree. Different designs are talken care of by using adapters between the XT and workover equipment.
To gain access to the well, the pressure control assembly (LRP) is fist connected to the Christmas tree. Then the workover riser and EDP are connected to the LRP. A second pressure control assembly (surface BOP) is attached to the top of the workover riser. A tool is run in to remove plug 10 to open the well 10. If only smaller tools are scheduled to be used during intervention, a smaller LRP and workover riser can be used. A tool is run in to engage with flange 36 to pull the inner plug 30.
The method of the invention therefore allows for a wider choice of both equipment and vessels and allows the equipment to be more specifically tailored to the work. When work is planned in a well, it will first be analysed what type of work is necessary. If only small tools are to be used, the choice of workover equipment will be chosen accordingly and a suitable vessel commissioned. After connecting the equipment to the well, a tool is run in to release and retrieve the plug. If the job is light, only the inner plug will be retrieved through the smallbore riser; The work in the well is completed and the equipment disconnected from the well. If it is desired to use larger tools, again a suitable size of workover riser and vessel is chosen. After connecting to the well, a tool is run in, this time to retrieve the main plug, allowing larger tools to be run into the well.
a main plug which includes a cylindrical housing, a number of first releasable locking devises for holding the housing in position within the bores and means for sealing between the housing and the bore; and
wherein the inner plug may be retrieved separately from the main plug.
2. The retrievable plug according to claim 1, wherein the inner plug comprises a number of second releasable locking devises for holding the inner plug in position within the main plug, and means for sealing between the inner plug and the main plug.
3. The retrievable plug according to claim 2, wherein the main plug and the inner plug have similar locking devises and sealing means.
4. The retrievable plug according to claim 1, wherein the main plug and the inner plug are arranged coaxially within the bore.
5. The retrievable plug according to claim 1, further comprising a second inner plug which is arranged off centre in relation to a centre axis of the main plug.
6. The retrievable plug according to claim 2, wherein the housing comprises a plug bore which includes a ring groove, and the locking devises comprise locking dogs which are received in the ring groove.
7. A Christmas tree apparatus comprising a central bore which is sealed by at least one plug which comprises a main plug and at least one inner plug that is releasably mounted in the main plug.
a tubing hanger which is mounted in the central bore and which includes a vertical tubing hanger bore and a horizontal production passage which extends between the tubing hanger bore and a horizontal production outlet in the Christmas tree;
wherein the plug is located in the tubing hanger bore above the production passage.
a tree cap which is located in the central bore and which includes a vertical passage;
wherein the plug is located in the vertical passage.
10. A method for well intervention in a well comprising a Christmas tree and at least one plug which is located in the Christmas tree and which includes a main plug and at least one inner separately retrievable plug, in the method comprising:
retrieving the plug with either the inner plug or both the main plug and the inner plug through the riser; and
performing the intervention.
re-setting the plug with either the inner plug or both the main plug and the inner plug; and
disconnecting the subsea lubricator or workover riser from the Christmas tree.
US10/557,435 2003-05-22 2004-05-19 Dual-type plug for wellhead Expired - Fee Related US7654329B2 (en)
NO20032330 2003-05-22
NO20032330A NO322829B1 (en) 2003-05-22 2003-05-22 Gjenopptagbar plug, xmas tree connector and method of feeding for intervention in a well with at least one plug
PCT/NO2004/000151 WO2004104364A1 (en) 2003-05-22 2004-05-19 Dual-type plug for wellhead
US20070074870A1 true US20070074870A1 (en) 2007-04-05
US7654329B2 US7654329B2 (en) 2010-02-02
ID=19914789
US10/557,435 Expired - Fee Related US7654329B2 (en) 2003-05-22 2004-05-19 Dual-type plug for wellhead
US (1) US7654329B2 (en)
GB (1) GB2418945B (en)
NO (1) NO322829B1 (en)
WO (1) WO2004104364A1 (en)
US6109353A (en) * 1995-09-20 2000-08-29 Expro North Sea Limited Single bore riser system
GB8617698D0 (en) 1986-07-19 1986-08-28 Graser J A Wellhead apparatus
EP1350919B1 (en) * 1997-10-07 2005-12-14 FMC Technologies, Inc. A blow out preventer adapter for subsea well completion
2003-05-22 NO NO20032330A patent/NO322829B1/en not_active IP Right Cessation
2004-05-19 WO PCT/NO2004/000151 patent/WO2004104364A1/en active Application Filing
2004-05-19 GB GB0526178A patent/GB2418945B/en not_active Expired - Fee Related
2004-05-19 US US10/557,435 patent/US7654329B2/en not_active Expired - Fee Related
US6810954B2 (en) * 2000-01-27 2004-11-02 Kvaerner Oilfield Products, Inc. Production flow tree cap
GB2418945B (en) 2007-05-23
WO2004104364A1 (en) 2004-12-02
NO20032330L (en) 2004-11-23
NO20032330D0 (en) 2003-05-22
GB0526178D0 (en) 2006-02-01
US7654329B2 (en) 2010-02-02
GB2418945A (en) 2006-04-12
NO322829B1 (en) 2006-12-11
US7150323B2 (en) 2006-12-19 Shoulder ring set on casing hanger trip
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LINDLAND, HANS JORGEN;FOLKNER, STEIN;REEL/FRAME:018399/0220;SIGNING DATES FROM 20060907 TO 20060922
Owner name: FMC KONGSBERG SUBSEA AS,NORWAY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LINDLAND, HANS JORGEN;FOLKNER, STEIN;SIGNING DATES FROM 20060907 TO 20060922;REEL/FRAME:018399/0220