CA2415631A1 - Backpressure adapter pin and method of use - Google Patents
Backpressure adapter pin and method of use Download PDFInfo
- Publication number
- CA2415631A1 CA2415631A1 CA002415631A CA2415631A CA2415631A1 CA 2415631 A1 CA2415631 A1 CA 2415631A1 CA 002415631 A CA002415631 A CA 002415631A CA 2415631 A CA2415631 A CA 2415631A CA 2415631 A1 CA2415631 A1 CA 2415631A1
- Authority
- CA
- Canada
- Prior art keywords
- tubing
- backpressure
- adapter pin
- tubing string
- hanger
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/02—Surface sealing or packing
- E21B33/03—Well heads; Setting-up thereof
- E21B33/04—Casing heads; Suspending casings or tubings in well heads
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/12—Packers; Plugs
Abstract
A tubing assembly including a tubing string and tubing hanger provides a fluid passage with backpressure threads for securing a backpressure plug in a fluid-tight seal below the tubing hanger, so that the tubing hanger can be removed from the tubing string. The back pressure threads are preferably incorporated in a backpressure adapter pin connected between the tubing string and the tubing hanger. The adapter pin may also incorporate external weight-bearing shoulders for snubbing and/or suspending the tubing assembly. The backpressure plug is inserted or removed using a backpressure plug tool that slides through a packing in a pressurized casement that maintains pressure in an axial passage through a control stack of the wellhead.
Description
SOR File No.9-13523-31CA
BACKPRESSURE ADAPTER PIN AND METHODS OF USE
CROSS-REFERENCE TO RELATED APPLICATIONS
This is th.e first application filed for the present invention.
MICROFICHE APPENDIX
Not Applicable.
TECHNICAL FIELD
The invention relates to the field of oil and gas well operations, and more particularly to a backpressure adapter pin and method of using the adapter pin to facilitate servicing operations for oi.l and gas wells.
BACKGROUND OF THE INVENTION
Modern methods for st=imulating hydrocarbon flow in oil and gas wells, has increased demand for well servicing knowledge and equipment. Conunon wel=L servicing operations include removing and instal=l.ing spools, valves, blowout preventors and other elements in a control stack on the wellhead, inserting downhole tools =into the well, and/or injecting high-pressure well stimulation fluids. Modern equipment permits many of these operations to be performed without killing the wel=L. ~l'his is advantageous because killing fluids are expensive and have the potential to reverse the beneficial effects of a well stimulation procedure.
The Applicant has invented many methods and tools for protecting wellhead components from pressurized fracturing fluid, to permit the fluid to be pumped into hydrocarbon wells, as described, for example, in co-pending SOR File No.9-13523-31CA
G
United States Patent Application Patent number 6,364,024, entitled BLOWOUT PREVENTOR PROTEC'_TOR AND ME~PHOD OF USING
SAME, which issued on January 28, 2000. The fracturing fluids may be strongly acidic, or alkaline fluids and may be loaded with an abrasive proppant such as bauxite or sharp sand. Applicant's blowout preventor protectors have several advantages over the prior art, particularly because they permit a tubing st=ring to be run into or out of the well, and accessed during the stimulation treatment. In order to insert the blowout: preventor prote~~tor into the wellbore, the tubing hanger must be removed. Before the tubing hanger can beg removed, the tubing si=ring must be plugged to prevent. an escape of hydrocarbons too atmosphere.
This is preformed by setting a plug in the tubing string using a wireline lubricator, for example. This is an expensive and time consuming procedure that requires the use of wireline equipment to set the plug, as well as to remove it. As can be appreciated by those skilled in the art, if the tubing st:rinc~ is to be used during the stimulation process, for example as a "dead st=ring" used to monitor downhole pressurf=, or as an extra stirnulation fluid conduit or "flow back" tubing, the wireline plug must be set and removed two times during the well stimulation process. A first t=une 1=o remove the tubing hanger, and a second time to re-attach it to the tubing string.
As is known in the art, some tubing hangers have backpressure threads for_ receiving commercially available plugs to seal the tubing string. Thus, the tubing hanger serves as a common point for sealing both annular and circular spaces in the well,. as is well known in the art.
Consequently, it is possib:Le to remove and install the control stack elements without having to plug the production tubing using a wireline plug. However, if the SOR File No.9-13523-31CA
tubing hanger is removed, the plug is removed with it, leaving the tubing string open to atmosphere. Since many well servicing operations require that the tubing hanger be removed and/or set, =i_t is generally necessary to call in wireline equipment with crew at least twice during each such well servicing procedure.
To reduce the costs associated with well servicing procedures , i t i:~ thereforedesirable to provide a method and apparatus for permit=ting a tubing string to be plugged below a tubing hanger without the use of wireline equipment.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a method and apparatus for selectively plugging a production tubing below a tubing hanger in a live hydrocarbon well.
The invention therefore provides a backpressure adapter pin for use in well servicing operations. The backpressure adapter pin comprises a tubing joint having a top and a bottom end and an axial passage that extends between the top and bottom ends, t:he top and bottom ends being adapted to be connected between a tubing string and a tubing hanger, wherein an inner wall of the axial passage includes backpressure threads adapted t=o retain a backpressure plug that. is removably secured in a fluid-tight seal by the backpressu.re threads of the adapter pin.
The backpressure adapter p.in may be adapted to be sealingly connectecl to a top of a coil tubing string or a jointed tubing string, and may be inserted or removed using a backpressure plug tool.
SOR File No.9-13523-31CA
An outer wall of the adapter pin may be contoured so that when the adapter pin is connected i~o the tubing string, the adapter pin provides a 'weight-bearing shoulder for supporting and/or snubbing the tubing string.
The invention furtrer provides a tubing assembly comprising a tubing string, and tubing hanger, the tubing hanger supporting the tubing string in a control stack for an oil or gas well. The tubing assembly comprises a backpressure thread on an internal wall of the tubing assembly below the tubing hanger. 'hhe backpressure thread is adapted to secure a backpressure plug in a fluid-tight seal for sea ling the tubing string when the tubing hanger is removed from the tubing string.
The tubing assembly may further comprise a contoured surface below t=he tubing hanger that. is shaped to provide a weight--bearing shoulder for suspending and/or snubbing the tubing string.
The backpressure threads may be located on an inner wall of an adapter pi:n connected between the tubing hanger and the tubing string.
The invention further provides a method for removing a tubing hanger from a wellhead of a live well.
The method comprises a first step of- inserting a plug in a backpressure adapter pin installed between the tubing hanger and the tubing string to seal the tubing string.
After the plug is inserted, a landing joint i~~ connected to a top of the tubing hander, and the tubing hanger and the tubing string are lif.~ed from a tubing head spool of the wellhead by raising the landing joint. An annulus of the live well is then closed and the tubing string is supported SOR File No.9-13523-31CA
below the tubing hanger. The landing joint and the tubing hanger are then removed from the tubing string.
The tubing string may be raised a predetermined distance to align the adapter pin with slip blocks for supporting the tubing mitring and the slip blocks are closed around the adapter pin t=o support the tubing string.
The invention furt=her provides a method for inserting a backpressure plug into a tubing assembly connected to a tubing hanger from which the tubing assembly is suspended in a live well . The method compr_ ises a first step of mounting a backpressure plug tool to a top of a control stack on the wel=L. Fluid pressure is then balanced between the well and a space between the back:pressure plug tool and a blocking point in the control stack beneath the backpressure plug tool. After the fluid pressure is balanced, a backpressure plug is lowered through the axial passage using the backpressure plug tool and screwed into a backpressure adapter p n to plug the tubing string.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
FIG. 1a is a schematic diagram of an adapter pin in accordance with the present invention, having pin threaded top and bottom ends;
FIG. 1b is a schematic diagram of an adapter pin in accordance with the present invention, having box threaded top and bottom ends SOR File No.9-13523-31CA
FIG. 1c is a schematic diagram of an adapter pin in accordance with t=he present invention, with a pin threaded top end, a box threaded bottom end, and shoulders for snubbing and supporting a tubing assembly;
FIG. 1d is a schematic diagram of an adapter pin in accordance with t:he present invention, with a pin threaded bottom end, a box threaded top end, and a shoulder for supporting a tubing assembly;
FIG. 1e is a schematic diagram of an adapter pin in accordance with the invention, having box threaded ends, and a recess defining shoulders for snubbing and supporting a tubing assembly;
FIG. 2 is a schematic diagram of an adapter pin in accordance with the invention having a shoulder for supporting a tubing assembly, installed between a tubing hanger and tubing string supported by the tubing hanger;
FIG. 3 is a ~~chemat=is diagram of a backpressure plug tool for setting or retrieving a backpres:~ure plug;
FIG. 4 schematically illustrates principal components for removing or =Landing a tubing hanger using the backpressure pin adapter in accordance with the present invention; and FIG. 5 schematically illustrates alternative components for removing or landing the tubing hanger using the backpressure pin adapter in accordance with the present invention.
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
SOR File No.9-13523-31CA
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention provides a method and apparatus for permitting the setting of a backpressure plug below a tubing hanger within r-each c>f a backpressure plug tool. The apparatus is preferably embodied in a backpressure adapter pin, which may be a tubing collar, for example. The apparatus may alternatively be otherwise integrated with the tubing string below the tubing hanger, so that the tubing hanger may be removed or landed without setting or retrieving a wireline plug. Methods are provided for setting the backpressure plug, and removing a tubing hanger without the use of a wireline tool.
As illustrated in FIGS. 1a-e, the backpressure adapter pin 10 i:~ a tubing joint having substantially cylindrical inner 12 and outer 14 walls, a top end 16 and a bottom end 18. The t:op end 16 is adapted to be connected to a tubing hanger, or to a pup joint connected to the tubing hanger. The bot=tom end 18 is adapted to be connected to a tubing string. As il_lust:rated in FIG. 1a the top end 16 and bottom emd 18 are external upset end (EuE) threaded so that the adapter pin 10 can threadably connect to standard tubing Inanger:> and standard tubing strings collars. The inner wall 12 of the adapter pin 10 has backpressure threads '~0 commonly used in tubing hangers for receiving and retaining a backpressure plug (not illustrated) in a fluid-tight seal.
The adapter pin 10 illustrated in F'IG. 1a is pin threaded EuE on both the top end 16 and bott=om end 18 , so that, for example, the adapter pin 10 (of FIG. 1a) can connect to a tubing hanger at the top end 16, and to a tubing collar at the Oottom end 18.
SOR File No.9-13523-31CA
_ g _ The adapter pin 10 illustrated in FIG. 1b is box threaded EuE on both the top end 15 and bott:om end 18 , so that, for example, the adapter pin 10 (of FIG. 1b) can be connected to a pin thz:eaded EuE pup joint at the top end 16 and to a joint of a tmbing mitring ate the bottom end 18. The adapter pin 10 shown in FIG. 1 can therefore be used as a tubing collar, the use and function of which are well known in the art.
The adapter p.in 10 shown in FIG. 1c is pin threaded EuE on the top end 16, for coupling with a tubing hanger, for example, and box threaded EuE on the bottom end 18, for connection to a joint of a tubing string. The outer wall 14 of the adapter pin 10 _illustrated in FIG. 1c includes two weight bearing circumferential shoulders. A
shoulder 19a is adapted to mate with a slip block, and a shoulder 19b is adapted to :mate with a snubbing block. The shoulder 19a is contoured to mate with the slip block of a slip spool, described in applicant's co-pending United States Patent application, serial number 10/034,032, filed December 19, 2001, entitled SLIP SFOOL AND METHOD OF USING
SAME, which is incorporated herein by reference.
The adapter pin 10 illustrated in F=LG. 1d has box threaded EuE top end 16, and pin threaded EuE bottom end 18, permitting cc.nnection of a tubing collar to the bottom end 18, and a pup joint to the top end 16. The adapter pin 10 shown in :SIG. 1d has a circumferential shoulder 19a which may be used to support a tubing string to which it is connect=ed. The shoulder 19a shown in FIG. 1d is designed to be ;~upport;ed by substantially any slip block.
FIG. 1e il.lustrate:~ an adapter pin :LO that is box threaded EuE on bot=h the tow end 16 and bottom end 18, and SOR File No.9-13523-31CA
__ provides shoulders 19a For supporting and 19b for snubbing the tubing string. The shoulders 1'~a,b are respectively formed in a circumferential recess in the outer wall 14.
As will be understood by persons skilled in the art, although the adapter pin 10 shown in FIGS 1a-1e is configured with EuE t=hreads, other thread patterns or other types of connections can be used for the same purpose. As will be further understood, although the illustrated adapter pins 10 are str.-aight-through adapters, the top end 16 and bottom end :~8 m~~y have different diameters, so that the adapter pin 10 al~~o Nerves as a size adapter. As will be further understood, although the illustrated adapter pins 10 are configured for use with jointed tubing, they may be readily adapted to use with coil tubing using joints and connectors that are well known in the art.
FIG. 2 illustrates part of a wellhead control stack 24 that includes a blowout preventor (BOP) 26, and a tubing head spool 28. Ln~>ide the control stack 24 and the well below, is a tubing assembly that. includes of a tubing hanger 30 landed in the t=ubing head spool 28, the adapter pin 10 connected to the tubing hanger 30 and to a tubing string 32. As is understood by those skilled in the art, the control stack 24 may include other elements than the BOP 26 and the tubing head ~~pool 28. An axial passage 36 extends vertically through th.e control stack 22, providing access to the tubing string 32. 'The BOP 26 is illustrated in a closed condition, indicating that the axial passage is sealed. This is necessary in a live well to prevent hydrocarbons from escaping to atmosphere.
As is known i.n the art, many actions during well servicing operations on live wells require the shutting off of one or more of the axial pa~~sage 36, the tubing SOR File No.9-13523-31CA
string 32, and an annular space (hereinafter refereed to as the annulus 35) between the interior of the tubing string 32, and an exterior wall of the tubing string 32. As is well known in t:he art, the BOP 26 norma-~ly includes a complement of blind rams adapted to seal the axial passage 36, and a complement of. tubing rams adapted to provide a fluid seal around a tubing string. If there is no obstruction in the axial passage 36, the blind rams can be closed to seal the well bore. However, if the axial passage 36 is obstructed by t-he tubing string 32, tubing rams (of appropriate configuration) are used to block the flow through the annul us 3 '> .
The tubing head spool 28 is mounted to the top of the well and secures the well casing 34 and supports the tubing hanger 30. The illustrated tubing head spool 28 further includes a pair of valves 37 used for known purposes outside of t=he scope of the present invention. The tubing hanger 30 seals against an inner wall of the tubing head spool 28, which inclu<~es at. east two lock bolts 38 for locking the tubing hanger 30 against a seat of the tubing head spool. :?8. The tubing hanger 30 therefore seals the annulus 35 of the well..
A passage through the tubing hanger 30 includes threads for a rigid connection from above, for example, for connection of a landing jo_i.nt (not illustrated). Further, while many tubing hangers known in the art have backpressure threads on an inner wall for threaded engagement of a backpressure plug, the tubing hanger 30 does not. In accordance with the present invention, the backpressure threads are removed to a lower point in the tubing assembly. Ire the illustrated embodiment, the SOR File No.9-13523-31CA
backpressure threads 20 are provided on an inner wall 12 of the adapter pin 10.
The adapter pin 10 shown in FIG. 2 resembles the adapter pin 10 illustrated in FIG. 1d, insofar as it provides a shoulder 19a fo=r supporting the tubing string 32, but does not provide a shoulder for snubbing the tubing string 32. It is different from the embodiment shown in FIG. 1d in that it provides the shoulder at the bottom end 18, rather than in the middle, and t=hat the shoulder 19a of the adapter pin shown FIG. 1d is square, whereas the shoulder 19a of tine adapter pi.n 10 shown in FIG. 2 is beveled.
As will be appreciated by those skilled in the art, the most convenient and economical time for installing the adapter pin 10 in a tubing string is during completion of the well, when the tubing string is being run into the well.
The well illustrated in FIG. 2 is a live well, a pressure difference between the hydrocarbon reservoir and atmosphere propels well fluids upwards, and the fluids are blocked in the annulus 35 b=y the tubing hanger 30, but can flow through the tubing string 32 irzto the axial passage as far as the blind rams of the BOP 26. In order to service the wellhead, or perform other well serving procedures, it is desirable to block the tubing string below the BOP 26.
This is performed by instal7_ing a backpressure plug tool 44 that includes a pressure containment flange 46, schematically .illustrated in FIG. 3.
The backpressure plug tool 44 includes a backpressure plug insta:Llation rod 48 having' a top end 50 that permits manipulation of a backpressure plug 56, when a SOR File No.9-13523-31CA
bottom end 52 of the backpressure plug tool 44 is inserted into the axial passage 36 of the control stack 24. The bottom end 52 is adapted for coupling with an adapter head 54. The adapter head 54 engages the backpressure plug 56.
The rod 48 extends through a packing 60 that permits the rod 48 to be moved rotationally and vertically, even if the axial passage 36 i.s under pressure. The outer diameter of the bottom end 52 of the rod 48 may be larger than that of the rod 48, so that the tool cannot be ejected from the pressure containment flange 46.
A method for inserting the backpressure plug 56 into the tubing assembly therefore includes steps of mounting the backpressure plug tool 44 with the pressure containment flange 46 to tl~.e top of the BOP 26. At this point, the axial passage 36 above the blind rams of the BOP 26 is at atmospheric pressure. A.s is well 'understood by those skilled in the art, the pressure containment flange 46 generally includes a pressure test port (not shown) used for pressure balancing and pressure release. Consequently, after the backpressure plug tool is installed on the BOP 26, the well pressure is balanced across t=he blind rams of the BOP 26 using a pressure bleed hose (not shown) connected between the tubing head spool 28 and the backpressure containment flange 46, in a manner well known in the art.
The blind rams of the blowout. preventor 26 are then opened, the rod 48 is lowered, moving the backpressure plug 56 down through the pressurized axial passage 36 and to the tubing hanger 30. Once the backpressure plug 56 is in position above the backpressu:re threads 20 of the adapter pin 10, the backpressure plug tool 44 is used to rotate the backpress~are plug 56 until it is sealingly SOR File No.9-13523-31CA
secured in the backpressure threads 20. This may involve using a wrench at the top end 50 of the rod 48, in a manner known in the art.
After the backpressure plug 56 is set, the axial passage 36 remains under pressure, but isol,~ted from the well pressures below the plug, a:~ the well fluids are blocked from rising up through the tubing string 32. The pressure above the backpressure plug 56 is then bled off and the backpressure plug tool is removed. The blowout preventor 26 may also be removed, as the tubing hanger 30 blocks the annulus 35, and the backpressure plug 56 blocks the tubing string 32, below the BOP 26.
Removing the backpressure plug 56 from the adapter pin 10 is performed by reversing the steps described above.
The BOP 26 (if not already _installed on the control stack) is installed and the blind rams are closed. The pressure containment flange 46 with the backpressure plug tool 44 are installed and the pressure is balanced above the backpressure plug, as described above. The backpressure plug tool 44 is then used to remove the backpressure plug 56. The backpressur_e tool 44 is then pulled up to a position above the blind rams of the BOP 26. The blind rams are closed, sealing the axial p<~ssage 36. The pressure is then bled off above the blind rams of the BOP 26, and the backpressure containment flange 46 with the backpressure plug tool 44 are r_emowed.
There are a number of well servicing procedures that are facilitated by separating the point at which the annulus 35 is blocked from the point where the tubing string 32 is sealed. It is well known in the art that the tubing hanger 30 must. be set. in the tubing head spool 28 in order to suspend the tubing string 32 in the well after the SOR File No.9-13523-31CA
tubing string 32 has been .run into the well during well completion, as described in Applicant's co-pending United States Patent application Serial No. 09/791,900 entitled METHOD AND APPARATUS FOR INSERTING A TUBTNG HANGER INTO A
LIVE WELL, which was filed on February 23, 2001, the specification of which is incorporated herein by reference.
It is also well known that the tubing hanger 30 must be removed from the tubing head spool 28 when a mandrel of a blowout preventor protector is to be inserted through the wellhead, as explained for example, in the applicant's above-referenced United States patent No. 6,364,024.
Generally, these procedures involve removing the tubing hanger 30 from the tubing head spool 28, and disconnecting the tubing hanger 30 from the tubing string 32.
Accordingly, the invention provides a method for removing the tubing hanger 30 from a live well, without having to plug the production tubing using a wireline tool.
FIG. 4 schematically illustrates a control stack 24 that includes the tubing head spool 28, the BOP 26, and a slip spool 70, described in Applicant's patent application filed December. 19'h, 2002. As described in that patent application, the control stack 24 includes an annular adapter 72. The annular adapter 72 is connected to a top of the control stack 24. A Bowen union 74 is mounted to a top of the slip spool 70 and the annular adapter 72 is connected to the Bowen union 74 by a lockdown nut 76. The annular adapter 72 includes bleed-of_f valves 78 that control flow through radial passages 80. A landing joint 86 can be reciprocated through packing 82 that inhibits an escape of pressurized well fluids to atmosphere.
The slip spool 70 includes a set of slip blocks 84 that are controlled by hydraulic cylinders, as explained in SOR File No.9-13523-31CA
detail in Applicant's application filed December 19th. A
top edge of each of the slip blocks is contoured to complement the beveled shoulder 19a of the adapter pin 10 illustrated in FIGS. 2, 3 & 4.
A tubing assembly shown in FIG. 4 includes the tubing hanger 30, the adapter p:in 10, arid tubing string 32, all of which have been described above. The tubing assembly is illustrated in side elevational view, so the backpressure plug 56, and backpressure threads 20 are not visible. The landing joint 86 is connected to a top end of the tubing hanger 3G.
Accordingly the method of removing the tubing hanger 30 after the backpressure plug 56 is set in the adapter pin 10, involves first installing the slip spool 70 and annular adapter 72 onto the top of the control stack 24, above the BOP 26. Once these spools are sealed and pressure balanced, th.e landing joint 86 is lowered down through the axial passage 36, and into the tubing hanger 30 where it is rotated to engage box threads in a top of the tubing hanger 30.
The lock bolts 38 are retracted and the landing joint 86 is then hoisted to raise the tubing assembly up through the control stack 24. Hoisting the landing joint 86 unseats the tubing hanger 30. Once the tubing hanger 30 and adapter pin 10 have been pulled up f_ar enough to clear the tubing rams of the BOP 26, the tubing rams may be closed around the tubing string 32, blocking the fluid path between the axial passage above the BOP 26 and the reservoir below. After the tubing rams are closed, the bleed-off valve 78 is opened to release the pressurized fluid contained in the axial passage 36 above the tubing rams of the BOP 26. After the adapter pin 10 is raised SOR File No.9-13523-31CA
above a top of the ship blocks 84 , the slip blocks 84 are extended, and the landing joint 86 is lowered so that a weight of the tubing string is supported by the slip blocks 84.
Once the pressure in the axial passage 36 above the tubing rams is released, the annular adapter 72 is removed by disconnecting the landing joint 86 and unscrewing the lockdown nut 76. The tubing hanger 30 is therefore exposed, and can be removed. If desired, the Bowen Union 74 may also be removed.
Steps involved in inserting the tubing hanger 30 into the tubing head spool 28 are substantially the reverse of the method of removing the tubing hanger 30, and will not be repeated here.
Those skilled in the art: will understand that the slip spool 70 is not essential to the procedure described above, and other slip devices can be used to temporarily support the tubing string. For example, after the lockdown nut 76 is released, the adapter spool 72 and the landing joint may be raised further so that the adapter pin 10 is higher than the control stack, at which point it can be supported by a conventional slip block, for example.
FIG. 5 schematically illustrates a control stack that is different form the one described above with reference to FIG. 4. The s:Lip spool 70 is rE=placed with a hydraulic slip spool 90 that supports the tubing string 32 using slip jaws 92, as described in Applicant's United States Patent Application ~lo. filed on December 20, 2002, the specification of which is incorporated herein by reference. The slip jaws 92 are shown in a retracted position. A base plate of the hydraulic slip spool 90 is SOR File rJo.9-13523-31CA
provisioned with a hydraulic system 94. The hydraulic system 94 includes t:wo or more hydraulic cylinder 96 operatively coupled t:.o respective piston rods 98. The details and operation of such a hydraulic system is well known in the art and not described here. In this embodiment, the bar_kpressurc_=_ threads 20 for receiving the backpressure plug 56 are incorporated in a tubing joint of the tubing string 32.
The invention therefore permits a tubing string to be plugged and a tubing hanger to be removed from a live well without the use of vaireline equipment. The method and apparatus in accordance with the invention permit the backpressure plug to be set or removed more quickly than can be accomplished using a wireline lubrication, and at much less expense. Consequently, the invention permits many well completion and servicing operations to be performed more quickly at a reduced cost.
The embodirnent(s) of the invention described above is(are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.
BACKPRESSURE ADAPTER PIN AND METHODS OF USE
CROSS-REFERENCE TO RELATED APPLICATIONS
This is th.e first application filed for the present invention.
MICROFICHE APPENDIX
Not Applicable.
TECHNICAL FIELD
The invention relates to the field of oil and gas well operations, and more particularly to a backpressure adapter pin and method of using the adapter pin to facilitate servicing operations for oi.l and gas wells.
BACKGROUND OF THE INVENTION
Modern methods for st=imulating hydrocarbon flow in oil and gas wells, has increased demand for well servicing knowledge and equipment. Conunon wel=L servicing operations include removing and instal=l.ing spools, valves, blowout preventors and other elements in a control stack on the wellhead, inserting downhole tools =into the well, and/or injecting high-pressure well stimulation fluids. Modern equipment permits many of these operations to be performed without killing the wel=L. ~l'his is advantageous because killing fluids are expensive and have the potential to reverse the beneficial effects of a well stimulation procedure.
The Applicant has invented many methods and tools for protecting wellhead components from pressurized fracturing fluid, to permit the fluid to be pumped into hydrocarbon wells, as described, for example, in co-pending SOR File No.9-13523-31CA
G
United States Patent Application Patent number 6,364,024, entitled BLOWOUT PREVENTOR PROTEC'_TOR AND ME~PHOD OF USING
SAME, which issued on January 28, 2000. The fracturing fluids may be strongly acidic, or alkaline fluids and may be loaded with an abrasive proppant such as bauxite or sharp sand. Applicant's blowout preventor protectors have several advantages over the prior art, particularly because they permit a tubing st=ring to be run into or out of the well, and accessed during the stimulation treatment. In order to insert the blowout: preventor prote~~tor into the wellbore, the tubing hanger must be removed. Before the tubing hanger can beg removed, the tubing si=ring must be plugged to prevent. an escape of hydrocarbons too atmosphere.
This is preformed by setting a plug in the tubing string using a wireline lubricator, for example. This is an expensive and time consuming procedure that requires the use of wireline equipment to set the plug, as well as to remove it. As can be appreciated by those skilled in the art, if the tubing st:rinc~ is to be used during the stimulation process, for example as a "dead st=ring" used to monitor downhole pressurf=, or as an extra stirnulation fluid conduit or "flow back" tubing, the wireline plug must be set and removed two times during the well stimulation process. A first t=une 1=o remove the tubing hanger, and a second time to re-attach it to the tubing string.
As is known in the art, some tubing hangers have backpressure threads for_ receiving commercially available plugs to seal the tubing string. Thus, the tubing hanger serves as a common point for sealing both annular and circular spaces in the well,. as is well known in the art.
Consequently, it is possib:Le to remove and install the control stack elements without having to plug the production tubing using a wireline plug. However, if the SOR File No.9-13523-31CA
tubing hanger is removed, the plug is removed with it, leaving the tubing string open to atmosphere. Since many well servicing operations require that the tubing hanger be removed and/or set, =i_t is generally necessary to call in wireline equipment with crew at least twice during each such well servicing procedure.
To reduce the costs associated with well servicing procedures , i t i:~ thereforedesirable to provide a method and apparatus for permit=ting a tubing string to be plugged below a tubing hanger without the use of wireline equipment.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a method and apparatus for selectively plugging a production tubing below a tubing hanger in a live hydrocarbon well.
The invention therefore provides a backpressure adapter pin for use in well servicing operations. The backpressure adapter pin comprises a tubing joint having a top and a bottom end and an axial passage that extends between the top and bottom ends, t:he top and bottom ends being adapted to be connected between a tubing string and a tubing hanger, wherein an inner wall of the axial passage includes backpressure threads adapted t=o retain a backpressure plug that. is removably secured in a fluid-tight seal by the backpressu.re threads of the adapter pin.
The backpressure adapter p.in may be adapted to be sealingly connectecl to a top of a coil tubing string or a jointed tubing string, and may be inserted or removed using a backpressure plug tool.
SOR File No.9-13523-31CA
An outer wall of the adapter pin may be contoured so that when the adapter pin is connected i~o the tubing string, the adapter pin provides a 'weight-bearing shoulder for supporting and/or snubbing the tubing string.
The invention furtrer provides a tubing assembly comprising a tubing string, and tubing hanger, the tubing hanger supporting the tubing string in a control stack for an oil or gas well. The tubing assembly comprises a backpressure thread on an internal wall of the tubing assembly below the tubing hanger. 'hhe backpressure thread is adapted to secure a backpressure plug in a fluid-tight seal for sea ling the tubing string when the tubing hanger is removed from the tubing string.
The tubing assembly may further comprise a contoured surface below t=he tubing hanger that. is shaped to provide a weight--bearing shoulder for suspending and/or snubbing the tubing string.
The backpressure threads may be located on an inner wall of an adapter pi:n connected between the tubing hanger and the tubing string.
The invention further provides a method for removing a tubing hanger from a wellhead of a live well.
The method comprises a first step of- inserting a plug in a backpressure adapter pin installed between the tubing hanger and the tubing string to seal the tubing string.
After the plug is inserted, a landing joint i~~ connected to a top of the tubing hander, and the tubing hanger and the tubing string are lif.~ed from a tubing head spool of the wellhead by raising the landing joint. An annulus of the live well is then closed and the tubing string is supported SOR File No.9-13523-31CA
below the tubing hanger. The landing joint and the tubing hanger are then removed from the tubing string.
The tubing string may be raised a predetermined distance to align the adapter pin with slip blocks for supporting the tubing mitring and the slip blocks are closed around the adapter pin t=o support the tubing string.
The invention furt=her provides a method for inserting a backpressure plug into a tubing assembly connected to a tubing hanger from which the tubing assembly is suspended in a live well . The method compr_ ises a first step of mounting a backpressure plug tool to a top of a control stack on the wel=L. Fluid pressure is then balanced between the well and a space between the back:pressure plug tool and a blocking point in the control stack beneath the backpressure plug tool. After the fluid pressure is balanced, a backpressure plug is lowered through the axial passage using the backpressure plug tool and screwed into a backpressure adapter p n to plug the tubing string.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
FIG. 1a is a schematic diagram of an adapter pin in accordance with the present invention, having pin threaded top and bottom ends;
FIG. 1b is a schematic diagram of an adapter pin in accordance with the present invention, having box threaded top and bottom ends SOR File No.9-13523-31CA
FIG. 1c is a schematic diagram of an adapter pin in accordance with t=he present invention, with a pin threaded top end, a box threaded bottom end, and shoulders for snubbing and supporting a tubing assembly;
FIG. 1d is a schematic diagram of an adapter pin in accordance with t:he present invention, with a pin threaded bottom end, a box threaded top end, and a shoulder for supporting a tubing assembly;
FIG. 1e is a schematic diagram of an adapter pin in accordance with the invention, having box threaded ends, and a recess defining shoulders for snubbing and supporting a tubing assembly;
FIG. 2 is a schematic diagram of an adapter pin in accordance with the invention having a shoulder for supporting a tubing assembly, installed between a tubing hanger and tubing string supported by the tubing hanger;
FIG. 3 is a ~~chemat=is diagram of a backpressure plug tool for setting or retrieving a backpres:~ure plug;
FIG. 4 schematically illustrates principal components for removing or =Landing a tubing hanger using the backpressure pin adapter in accordance with the present invention; and FIG. 5 schematically illustrates alternative components for removing or landing the tubing hanger using the backpressure pin adapter in accordance with the present invention.
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
SOR File No.9-13523-31CA
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention provides a method and apparatus for permitting the setting of a backpressure plug below a tubing hanger within r-each c>f a backpressure plug tool. The apparatus is preferably embodied in a backpressure adapter pin, which may be a tubing collar, for example. The apparatus may alternatively be otherwise integrated with the tubing string below the tubing hanger, so that the tubing hanger may be removed or landed without setting or retrieving a wireline plug. Methods are provided for setting the backpressure plug, and removing a tubing hanger without the use of a wireline tool.
As illustrated in FIGS. 1a-e, the backpressure adapter pin 10 i:~ a tubing joint having substantially cylindrical inner 12 and outer 14 walls, a top end 16 and a bottom end 18. The t:op end 16 is adapted to be connected to a tubing hanger, or to a pup joint connected to the tubing hanger. The bot=tom end 18 is adapted to be connected to a tubing string. As il_lust:rated in FIG. 1a the top end 16 and bottom emd 18 are external upset end (EuE) threaded so that the adapter pin 10 can threadably connect to standard tubing Inanger:> and standard tubing strings collars. The inner wall 12 of the adapter pin 10 has backpressure threads '~0 commonly used in tubing hangers for receiving and retaining a backpressure plug (not illustrated) in a fluid-tight seal.
The adapter pin 10 illustrated in F'IG. 1a is pin threaded EuE on both the top end 16 and bott=om end 18 , so that, for example, the adapter pin 10 (of FIG. 1a) can connect to a tubing hanger at the top end 16, and to a tubing collar at the Oottom end 18.
SOR File No.9-13523-31CA
_ g _ The adapter pin 10 illustrated in FIG. 1b is box threaded EuE on both the top end 15 and bott:om end 18 , so that, for example, the adapter pin 10 (of FIG. 1b) can be connected to a pin thz:eaded EuE pup joint at the top end 16 and to a joint of a tmbing mitring ate the bottom end 18. The adapter pin 10 shown in FIG. 1 can therefore be used as a tubing collar, the use and function of which are well known in the art.
The adapter p.in 10 shown in FIG. 1c is pin threaded EuE on the top end 16, for coupling with a tubing hanger, for example, and box threaded EuE on the bottom end 18, for connection to a joint of a tubing string. The outer wall 14 of the adapter pin 10 _illustrated in FIG. 1c includes two weight bearing circumferential shoulders. A
shoulder 19a is adapted to mate with a slip block, and a shoulder 19b is adapted to :mate with a snubbing block. The shoulder 19a is contoured to mate with the slip block of a slip spool, described in applicant's co-pending United States Patent application, serial number 10/034,032, filed December 19, 2001, entitled SLIP SFOOL AND METHOD OF USING
SAME, which is incorporated herein by reference.
The adapter pin 10 illustrated in F=LG. 1d has box threaded EuE top end 16, and pin threaded EuE bottom end 18, permitting cc.nnection of a tubing collar to the bottom end 18, and a pup joint to the top end 16. The adapter pin 10 shown in :SIG. 1d has a circumferential shoulder 19a which may be used to support a tubing string to which it is connect=ed. The shoulder 19a shown in FIG. 1d is designed to be ;~upport;ed by substantially any slip block.
FIG. 1e il.lustrate:~ an adapter pin :LO that is box threaded EuE on bot=h the tow end 16 and bottom end 18, and SOR File No.9-13523-31CA
__ provides shoulders 19a For supporting and 19b for snubbing the tubing string. The shoulders 1'~a,b are respectively formed in a circumferential recess in the outer wall 14.
As will be understood by persons skilled in the art, although the adapter pin 10 shown in FIGS 1a-1e is configured with EuE t=hreads, other thread patterns or other types of connections can be used for the same purpose. As will be further understood, although the illustrated adapter pins 10 are str.-aight-through adapters, the top end 16 and bottom end :~8 m~~y have different diameters, so that the adapter pin 10 al~~o Nerves as a size adapter. As will be further understood, although the illustrated adapter pins 10 are configured for use with jointed tubing, they may be readily adapted to use with coil tubing using joints and connectors that are well known in the art.
FIG. 2 illustrates part of a wellhead control stack 24 that includes a blowout preventor (BOP) 26, and a tubing head spool 28. Ln~>ide the control stack 24 and the well below, is a tubing assembly that. includes of a tubing hanger 30 landed in the t=ubing head spool 28, the adapter pin 10 connected to the tubing hanger 30 and to a tubing string 32. As is understood by those skilled in the art, the control stack 24 may include other elements than the BOP 26 and the tubing head ~~pool 28. An axial passage 36 extends vertically through th.e control stack 22, providing access to the tubing string 32. 'The BOP 26 is illustrated in a closed condition, indicating that the axial passage is sealed. This is necessary in a live well to prevent hydrocarbons from escaping to atmosphere.
As is known i.n the art, many actions during well servicing operations on live wells require the shutting off of one or more of the axial pa~~sage 36, the tubing SOR File No.9-13523-31CA
string 32, and an annular space (hereinafter refereed to as the annulus 35) between the interior of the tubing string 32, and an exterior wall of the tubing string 32. As is well known in t:he art, the BOP 26 norma-~ly includes a complement of blind rams adapted to seal the axial passage 36, and a complement of. tubing rams adapted to provide a fluid seal around a tubing string. If there is no obstruction in the axial passage 36, the blind rams can be closed to seal the well bore. However, if the axial passage 36 is obstructed by t-he tubing string 32, tubing rams (of appropriate configuration) are used to block the flow through the annul us 3 '> .
The tubing head spool 28 is mounted to the top of the well and secures the well casing 34 and supports the tubing hanger 30. The illustrated tubing head spool 28 further includes a pair of valves 37 used for known purposes outside of t=he scope of the present invention. The tubing hanger 30 seals against an inner wall of the tubing head spool 28, which inclu<~es at. east two lock bolts 38 for locking the tubing hanger 30 against a seat of the tubing head spool. :?8. The tubing hanger 30 therefore seals the annulus 35 of the well..
A passage through the tubing hanger 30 includes threads for a rigid connection from above, for example, for connection of a landing jo_i.nt (not illustrated). Further, while many tubing hangers known in the art have backpressure threads on an inner wall for threaded engagement of a backpressure plug, the tubing hanger 30 does not. In accordance with the present invention, the backpressure threads are removed to a lower point in the tubing assembly. Ire the illustrated embodiment, the SOR File No.9-13523-31CA
backpressure threads 20 are provided on an inner wall 12 of the adapter pin 10.
The adapter pin 10 shown in FIG. 2 resembles the adapter pin 10 illustrated in FIG. 1d, insofar as it provides a shoulder 19a fo=r supporting the tubing string 32, but does not provide a shoulder for snubbing the tubing string 32. It is different from the embodiment shown in FIG. 1d in that it provides the shoulder at the bottom end 18, rather than in the middle, and t=hat the shoulder 19a of the adapter pin shown FIG. 1d is square, whereas the shoulder 19a of tine adapter pi.n 10 shown in FIG. 2 is beveled.
As will be appreciated by those skilled in the art, the most convenient and economical time for installing the adapter pin 10 in a tubing string is during completion of the well, when the tubing string is being run into the well.
The well illustrated in FIG. 2 is a live well, a pressure difference between the hydrocarbon reservoir and atmosphere propels well fluids upwards, and the fluids are blocked in the annulus 35 b=y the tubing hanger 30, but can flow through the tubing string 32 irzto the axial passage as far as the blind rams of the BOP 26. In order to service the wellhead, or perform other well serving procedures, it is desirable to block the tubing string below the BOP 26.
This is performed by instal7_ing a backpressure plug tool 44 that includes a pressure containment flange 46, schematically .illustrated in FIG. 3.
The backpressure plug tool 44 includes a backpressure plug insta:Llation rod 48 having' a top end 50 that permits manipulation of a backpressure plug 56, when a SOR File No.9-13523-31CA
bottom end 52 of the backpressure plug tool 44 is inserted into the axial passage 36 of the control stack 24. The bottom end 52 is adapted for coupling with an adapter head 54. The adapter head 54 engages the backpressure plug 56.
The rod 48 extends through a packing 60 that permits the rod 48 to be moved rotationally and vertically, even if the axial passage 36 i.s under pressure. The outer diameter of the bottom end 52 of the rod 48 may be larger than that of the rod 48, so that the tool cannot be ejected from the pressure containment flange 46.
A method for inserting the backpressure plug 56 into the tubing assembly therefore includes steps of mounting the backpressure plug tool 44 with the pressure containment flange 46 to tl~.e top of the BOP 26. At this point, the axial passage 36 above the blind rams of the BOP 26 is at atmospheric pressure. A.s is well 'understood by those skilled in the art, the pressure containment flange 46 generally includes a pressure test port (not shown) used for pressure balancing and pressure release. Consequently, after the backpressure plug tool is installed on the BOP 26, the well pressure is balanced across t=he blind rams of the BOP 26 using a pressure bleed hose (not shown) connected between the tubing head spool 28 and the backpressure containment flange 46, in a manner well known in the art.
The blind rams of the blowout. preventor 26 are then opened, the rod 48 is lowered, moving the backpressure plug 56 down through the pressurized axial passage 36 and to the tubing hanger 30. Once the backpressure plug 56 is in position above the backpressu:re threads 20 of the adapter pin 10, the backpressure plug tool 44 is used to rotate the backpress~are plug 56 until it is sealingly SOR File No.9-13523-31CA
secured in the backpressure threads 20. This may involve using a wrench at the top end 50 of the rod 48, in a manner known in the art.
After the backpressure plug 56 is set, the axial passage 36 remains under pressure, but isol,~ted from the well pressures below the plug, a:~ the well fluids are blocked from rising up through the tubing string 32. The pressure above the backpressure plug 56 is then bled off and the backpressure plug tool is removed. The blowout preventor 26 may also be removed, as the tubing hanger 30 blocks the annulus 35, and the backpressure plug 56 blocks the tubing string 32, below the BOP 26.
Removing the backpressure plug 56 from the adapter pin 10 is performed by reversing the steps described above.
The BOP 26 (if not already _installed on the control stack) is installed and the blind rams are closed. The pressure containment flange 46 with the backpressure plug tool 44 are installed and the pressure is balanced above the backpressure plug, as described above. The backpressure plug tool 44 is then used to remove the backpressure plug 56. The backpressur_e tool 44 is then pulled up to a position above the blind rams of the BOP 26. The blind rams are closed, sealing the axial p<~ssage 36. The pressure is then bled off above the blind rams of the BOP 26, and the backpressure containment flange 46 with the backpressure plug tool 44 are r_emowed.
There are a number of well servicing procedures that are facilitated by separating the point at which the annulus 35 is blocked from the point where the tubing string 32 is sealed. It is well known in the art that the tubing hanger 30 must. be set. in the tubing head spool 28 in order to suspend the tubing string 32 in the well after the SOR File No.9-13523-31CA
tubing string 32 has been .run into the well during well completion, as described in Applicant's co-pending United States Patent application Serial No. 09/791,900 entitled METHOD AND APPARATUS FOR INSERTING A TUBTNG HANGER INTO A
LIVE WELL, which was filed on February 23, 2001, the specification of which is incorporated herein by reference.
It is also well known that the tubing hanger 30 must be removed from the tubing head spool 28 when a mandrel of a blowout preventor protector is to be inserted through the wellhead, as explained for example, in the applicant's above-referenced United States patent No. 6,364,024.
Generally, these procedures involve removing the tubing hanger 30 from the tubing head spool 28, and disconnecting the tubing hanger 30 from the tubing string 32.
Accordingly, the invention provides a method for removing the tubing hanger 30 from a live well, without having to plug the production tubing using a wireline tool.
FIG. 4 schematically illustrates a control stack 24 that includes the tubing head spool 28, the BOP 26, and a slip spool 70, described in Applicant's patent application filed December. 19'h, 2002. As described in that patent application, the control stack 24 includes an annular adapter 72. The annular adapter 72 is connected to a top of the control stack 24. A Bowen union 74 is mounted to a top of the slip spool 70 and the annular adapter 72 is connected to the Bowen union 74 by a lockdown nut 76. The annular adapter 72 includes bleed-of_f valves 78 that control flow through radial passages 80. A landing joint 86 can be reciprocated through packing 82 that inhibits an escape of pressurized well fluids to atmosphere.
The slip spool 70 includes a set of slip blocks 84 that are controlled by hydraulic cylinders, as explained in SOR File No.9-13523-31CA
detail in Applicant's application filed December 19th. A
top edge of each of the slip blocks is contoured to complement the beveled shoulder 19a of the adapter pin 10 illustrated in FIGS. 2, 3 & 4.
A tubing assembly shown in FIG. 4 includes the tubing hanger 30, the adapter p:in 10, arid tubing string 32, all of which have been described above. The tubing assembly is illustrated in side elevational view, so the backpressure plug 56, and backpressure threads 20 are not visible. The landing joint 86 is connected to a top end of the tubing hanger 3G.
Accordingly the method of removing the tubing hanger 30 after the backpressure plug 56 is set in the adapter pin 10, involves first installing the slip spool 70 and annular adapter 72 onto the top of the control stack 24, above the BOP 26. Once these spools are sealed and pressure balanced, th.e landing joint 86 is lowered down through the axial passage 36, and into the tubing hanger 30 where it is rotated to engage box threads in a top of the tubing hanger 30.
The lock bolts 38 are retracted and the landing joint 86 is then hoisted to raise the tubing assembly up through the control stack 24. Hoisting the landing joint 86 unseats the tubing hanger 30. Once the tubing hanger 30 and adapter pin 10 have been pulled up f_ar enough to clear the tubing rams of the BOP 26, the tubing rams may be closed around the tubing string 32, blocking the fluid path between the axial passage above the BOP 26 and the reservoir below. After the tubing rams are closed, the bleed-off valve 78 is opened to release the pressurized fluid contained in the axial passage 36 above the tubing rams of the BOP 26. After the adapter pin 10 is raised SOR File No.9-13523-31CA
above a top of the ship blocks 84 , the slip blocks 84 are extended, and the landing joint 86 is lowered so that a weight of the tubing string is supported by the slip blocks 84.
Once the pressure in the axial passage 36 above the tubing rams is released, the annular adapter 72 is removed by disconnecting the landing joint 86 and unscrewing the lockdown nut 76. The tubing hanger 30 is therefore exposed, and can be removed. If desired, the Bowen Union 74 may also be removed.
Steps involved in inserting the tubing hanger 30 into the tubing head spool 28 are substantially the reverse of the method of removing the tubing hanger 30, and will not be repeated here.
Those skilled in the art: will understand that the slip spool 70 is not essential to the procedure described above, and other slip devices can be used to temporarily support the tubing string. For example, after the lockdown nut 76 is released, the adapter spool 72 and the landing joint may be raised further so that the adapter pin 10 is higher than the control stack, at which point it can be supported by a conventional slip block, for example.
FIG. 5 schematically illustrates a control stack that is different form the one described above with reference to FIG. 4. The s:Lip spool 70 is rE=placed with a hydraulic slip spool 90 that supports the tubing string 32 using slip jaws 92, as described in Applicant's United States Patent Application ~lo. filed on December 20, 2002, the specification of which is incorporated herein by reference. The slip jaws 92 are shown in a retracted position. A base plate of the hydraulic slip spool 90 is SOR File rJo.9-13523-31CA
provisioned with a hydraulic system 94. The hydraulic system 94 includes t:wo or more hydraulic cylinder 96 operatively coupled t:.o respective piston rods 98. The details and operation of such a hydraulic system is well known in the art and not described here. In this embodiment, the bar_kpressurc_=_ threads 20 for receiving the backpressure plug 56 are incorporated in a tubing joint of the tubing string 32.
The invention therefore permits a tubing string to be plugged and a tubing hanger to be removed from a live well without the use of vaireline equipment. The method and apparatus in accordance with the invention permit the backpressure plug to be set or removed more quickly than can be accomplished using a wireline lubrication, and at much less expense. Consequently, the invention permits many well completion and servicing operations to be performed more quickly at a reduced cost.
The embodirnent(s) of the invention described above is(are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.
Claims (21)
1. A backpressure adapter pin for use in well servicing operations, comprising a tubing joint having a top and a bottom end and an axial passage that extends between the top and bottom ends, the top and bottom ends being adapted for connection between a tubing string and a tubing hanger, wherein an inner wall of the axial passage includes backpressure threads adapted to retain a backpressure plug that is removably secured in a fluid-tight seal by the backpressure threads of the adapter pin.
2. A backpressure adapter pin as claimed in claim 1 wherein the top end is pin threaded to connect in a fluid-tight seal to one of the tubing hanger and a tubing joint connected to the tubing hanger.
3. A backpressure adapter pin as claimed in claim 1 wherein the bottom end is adapted to connect in a fluid-tight seal to a top of a coil tubing string.
4. A backpressure adapter pin as claimed in claim 1 wherein the bottom end is adapted to connect in a fluid-tight seal to a joint of a jointed tubing string.
5. A backpressure adapter pin as claimed in claim 1 wherein the backpressure threads are adapted to receive a backpressure plug of a type that is removable and securable using a backpressure plug tool.
6. A backpressure adapter pin as claimed in claim 1 wherein an outer wall of the adapter pin is contoured so that when the adapter pin is connected to the tubing string, the adapter pin provides a weight-bearing shoulder for supporting the tubing string.
7. A backpressure adapter pin as claimed in claim 1 wherein an outer wall of the adapter pin is contoured so that when the adapter pin is connected to the tubing string, the adapter pin provides a weight-bearing shoulder for snubbing the tubing string.
8. A backpressure adapter pin as claimed in claim 1 wherein an outer wall of: the adapter pin is contoured so that when the adapter pin is connected to the tubing string, the adapter pin provides a first weight-bearing shoulder for supporting the tubing string, and a second weight-bearing shoulder for snubbing the tubing string.
9. A backpressure adapter pin as claimed in claim 8 wherein the contour is rotationally symmetric, so that when the adapter pin is connected to the tubing string, the adapter provides the weight-bearing shoulder for suspending and snubbing independent of a rotational position of the adapter pin with respect to slip or snubbing blocks.
10. A tubing assembly, comprising:
a tubing string and a tubing hanger, the tubing hanger supporting the tubing string in a control stack above an oil or gas well; and a backpressure thread on an internal wall of the tubing assembly below the tubing hanger, the backpressure thread being adapted to removably secure a backpressure plug in a fluid-tight seal to seal the tubing string.
a tubing string and a tubing hanger, the tubing hanger supporting the tubing string in a control stack above an oil or gas well; and a backpressure thread on an internal wall of the tubing assembly below the tubing hanger, the backpressure thread being adapted to removably secure a backpressure plug in a fluid-tight seal to seal the tubing string.
11. A tubing assembly as claimed in claim 10 further comprising a contoured surface below the tubing hanger that is shaped to provide a weight-bearing shoulder for suspending the tubing string.
12. A tubing assembly as claimed in claim 10 further comprising a contoured surface below the tubing hanger that is shaped to provide a weight-bearing shoulder for snubbing the tubing string.
13. A tubing assembly as claimed in claim 10 wherein the backpressure threads are located on an inner wall of an adapter pin connected between the tubing hanger and the tubing string.
14. A tubing assembly as claimed in claim 13 wherein the adapter pin comprises a contoured surface that is shaped to provide a weight-bearing shoulder for suspending and a weight-bearing shoulder for snubbing the tubing string.
15. A tubing assembly as claimed in claim 14 wherein the contoured surface is rotationally symmetric so that the contoured surface provide; the weight-bearing shoulders independently of a rotational position of the adapter pin.
16. A method for removing a tubing hanger from a wellhead of a live well comprising steps of:
inserting a plug in a backpressure adapter pin installed between the tubing hanger and the tubing string to seal the tubing string;
connecting a demanding joint to a top of the tubing hanger, and lifting the tubing hanger and the tubing string from a tubing head spool of the wellhead by raising the landing joint;
closing an annulus of the live well;
supporting the tubing string below the tubing hanger;
and removing the landing joint and the tubing hanger from the tubing string.
inserting a plug in a backpressure adapter pin installed between the tubing hanger and the tubing string to seal the tubing string;
connecting a demanding joint to a top of the tubing hanger, and lifting the tubing hanger and the tubing string from a tubing head spool of the wellhead by raising the landing joint;
closing an annulus of the live well;
supporting the tubing string below the tubing hanger;
and removing the landing joint and the tubing hanger from the tubing string.
17. A method as claimed in claim 16 wherein the step of supporting comprises steps of:
raising the tubing string a predetermined distance to align the adapter pin with slip blocks for supporting the tubing string; and closing the slip blocks around the adapter pin to support the tubing string.
raising the tubing string a predetermined distance to align the adapter pin with slip blocks for supporting the tubing string; and closing the slip blocks around the adapter pin to support the tubing string.
18. A method as claimed in claim 16 wherein the step of closing the annulus comprises a step of closing annular rams of a blowout preventor to seal an annulus around the tubing string below the tubing hanger.
19. A method for inserting a backpressure plug into a tubing assembly connected to a tubing hanger from which the tubing assembly is suspended in a live well, comprising steps of:
mounting a backpressure plug tool to a top of a control stack of the well;
balancing a fluid pressure between the well and an axial passage between the backpressure plug tool and a blocking point in the control stack beneath the backpressure plug tool;
lowering a backpressure plug connected to the backpressure plug tool through the axial passage, the tubing hanger, and into a position above backpressure threads on an inner wall of the tubing assembly; and securing the backpressure plug in the backpressure threads to plug the tubing string.
mounting a backpressure plug tool to a top of a control stack of the well;
balancing a fluid pressure between the well and an axial passage between the backpressure plug tool and a blocking point in the control stack beneath the backpressure plug tool;
lowering a backpressure plug connected to the backpressure plug tool through the axial passage, the tubing hanger, and into a position above backpressure threads on an inner wall of the tubing assembly; and securing the backpressure plug in the backpressure threads to plug the tubing string.
20. A method as claimed in claim 19 wherein the step of opening comprises a step of opening blind rams of a blowout prevent:or in the control stack.
21. A method as claimed in claim 20 further comprising a steps of:
pulling the backpressure plug tool up above the blowout preventor;
closing the blind rams after the backpressure plug is secured; and venting the axial passage above the blowout preventor to bleed off the fluid pressure in the axial passage.
pulling the backpressure plug tool up above the blowout preventor;
closing the blind rams after the backpressure plug is secured; and venting the axial passage above the blowout preventor to bleed off the fluid pressure in the axial passage.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002415631A CA2415631A1 (en) | 2003-01-03 | 2003-01-03 | Backpressure adapter pin and method of use |
| US10/336,911 US6918439B2 (en) | 2003-01-03 | 2003-01-06 | Backpressure adaptor pin and methods of use |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002415631A CA2415631A1 (en) | 2003-01-03 | 2003-01-03 | Backpressure adapter pin and method of use |
| US10/336,911 US6918439B2 (en) | 2003-01-03 | 2003-01-06 | Backpressure adaptor pin and methods of use |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2415631A1 true CA2415631A1 (en) | 2004-07-03 |
Family
ID=33030430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002415631A Abandoned CA2415631A1 (en) | 2003-01-03 | 2003-01-03 | Backpressure adapter pin and method of use |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US6918439B2 (en) |
| CA (1) | CA2415631A1 (en) |
Families Citing this family (50)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2421348A1 (en) * | 2003-03-07 | 2004-09-07 | L. Murray Dallas | Apparatus for controlling a tool having a mandrel that must be stroked into or out of a well |
| CA2428613C (en) | 2003-05-13 | 2005-10-25 | Bob Mcguire | Casing mandrel with well stimulation tool and tubing head spool for use with the casing mandrel |
| US7604058B2 (en) * | 2003-05-19 | 2009-10-20 | Stinger Wellhead Protection, Inc. | Casing mandrel for facilitating well completion, re-completion or workover |
| US20090107684A1 (en) | 2007-10-31 | 2009-04-30 | Cooke Jr Claude E | Applications of degradable polymers for delayed mechanical changes in wells |
| US20040231845A1 (en) | 2003-05-15 | 2004-11-25 | Cooke Claude E. | Applications of degradable polymers in wells |
| US7032677B2 (en) * | 2003-06-27 | 2006-04-25 | H W Ces International | Multi-lock adapters for independent screwed wellheads and methods of using same |
| US7121345B2 (en) * | 2003-07-23 | 2006-10-17 | Fmc Technologies, Inc. | Subsea tubing hanger lockdown device |
| US7159652B2 (en) * | 2003-09-04 | 2007-01-09 | Oil States Energy Services, Inc. | Drilling flange and independent screwed wellhead with metal-to-metal seal and method of use |
| CA2444043C (en) * | 2003-10-08 | 2007-04-24 | L. Murray Dallas | Well stimulation tool and method for inserting a backpressure plug through a mandrel of the tool |
| US7395867B2 (en) | 2004-03-17 | 2008-07-08 | Stinger Wellhead Protection, Inc. | Hybrid wellhead system and method of use |
| US20050211442A1 (en) * | 2004-03-29 | 2005-09-29 | Mcguire Bob | System and method for low-pressure well completion |
| US7168495B2 (en) * | 2004-03-31 | 2007-01-30 | Oil States Energy Services, Inc. | Casing-engaging well tree isolation tool and method of use |
| US7278490B2 (en) * | 2004-12-28 | 2007-10-09 | Stinger Wellhead Protection, Inc. | Blast joint swivel for wellhead isolation tool and method of using same |
| US7484776B2 (en) | 2005-07-14 | 2009-02-03 | Stinger Wellhead Protection, Inc. | High-pressure threaded union with metal-to-metal seal, and metal ring gasket for same |
| US7392864B2 (en) * | 2005-07-15 | 2008-07-01 | Stinger Wellhead Protection, Inc. | Slip spool assembly and method of using same |
| US20080110639A1 (en) * | 2006-11-15 | 2008-05-15 | Starr Phillip M | Wellhead isolation mandrel with centralizing device |
| US20080196883A1 (en) * | 2006-11-15 | 2008-08-21 | Testa Gero D | Centralizing apparatus |
| US7806175B2 (en) * | 2007-05-11 | 2010-10-05 | Stinger Wellhead Protection, Inc. | Retrivevable frac mandrel and well control stack to facilitate well completion, re-completion or workover and method of use |
| US7789133B2 (en) * | 2008-03-20 | 2010-09-07 | Stinger Wellhead Protection, Inc. | Erosion resistant frac head |
| US8820400B2 (en) | 2008-03-20 | 2014-09-02 | Oil States Energy Services, L.L.C. | Erosion resistant frac head |
| CA2646231A1 (en) * | 2008-12-05 | 2010-06-05 | Tracy Earl Klotz | Safety torque tubing hanger and safety torque tubing drain |
| US9217319B2 (en) | 2012-05-18 | 2015-12-22 | Frazier Technologies, L.L.C. | High-molecular-weight polyglycolides for hydrocarbon recovery |
| US8899317B2 (en) | 2008-12-23 | 2014-12-02 | W. Lynn Frazier | Decomposable pumpdown ball for downhole plugs |
| US9587475B2 (en) | 2008-12-23 | 2017-03-07 | Frazier Ball Invention, LLC | Downhole tools having non-toxic degradable elements and their methods of use |
| US9506309B2 (en) | 2008-12-23 | 2016-11-29 | Frazier Ball Invention, LLC | Downhole tools having non-toxic degradable elements |
| US8496052B2 (en) | 2008-12-23 | 2013-07-30 | Magnum Oil Tools International, Ltd. | Bottom set down hole tool |
| US8079413B2 (en) | 2008-12-23 | 2011-12-20 | W. Lynn Frazier | Bottom set downhole plug |
| US9062522B2 (en) | 2009-04-21 | 2015-06-23 | W. Lynn Frazier | Configurable inserts for downhole plugs |
| US9127527B2 (en) | 2009-04-21 | 2015-09-08 | W. Lynn Frazier | Decomposable impediments for downhole tools and methods for using same |
| US9181772B2 (en) | 2009-04-21 | 2015-11-10 | W. Lynn Frazier | Decomposable impediments for downhole plugs |
| US9109428B2 (en) | 2009-04-21 | 2015-08-18 | W. Lynn Frazier | Configurable bridge plugs and methods for using same |
| US9562415B2 (en) | 2009-04-21 | 2017-02-07 | Magnum Oil Tools International, Ltd. | Configurable inserts for downhole plugs |
| US9163477B2 (en) | 2009-04-21 | 2015-10-20 | W. Lynn Frazier | Configurable downhole tools and methods for using same |
| US8631873B2 (en) * | 2011-03-04 | 2014-01-21 | Proserv Operations, Inc. | Tubing hanger—production tubing suspension arrangement |
| USD703713S1 (en) | 2011-07-29 | 2014-04-29 | W. Lynn Frazier | Configurable caged ball insert for a downhole tool |
| USD694281S1 (en) | 2011-07-29 | 2013-11-26 | W. Lynn Frazier | Lower set insert with a lower ball seat for a downhole plug |
| USD698370S1 (en) | 2011-07-29 | 2014-01-28 | W. Lynn Frazier | Lower set caged ball insert for a downhole plug |
| USD672794S1 (en) | 2011-07-29 | 2012-12-18 | Frazier W Lynn | Configurable bridge plug insert for a downhole tool |
| USD694280S1 (en) | 2011-07-29 | 2013-11-26 | W. Lynn Frazier | Configurable insert for a downhole plug |
| USD657807S1 (en) | 2011-07-29 | 2012-04-17 | Frazier W Lynn | Configurable insert for a downhole tool |
| USD673183S1 (en) | 2011-07-29 | 2012-12-25 | Magnum Oil Tools International, Ltd. | Compact composite downhole plug |
| USD673182S1 (en) | 2011-07-29 | 2012-12-25 | Magnum Oil Tools International, Ltd. | Long range composite downhole plug |
| USD684612S1 (en) | 2011-07-29 | 2013-06-18 | W. Lynn Frazier | Configurable caged ball insert for a downhole tool |
| CN106968631B (en) * | 2017-04-24 | 2019-03-15 | 延长油田股份有限公司志丹采油厂 | A kind of long-acting anti-oil leakage device of well mouth of oil well |
| US11208856B2 (en) | 2018-11-02 | 2021-12-28 | Downing Wellhead Equipment, Llc | Subterranean formation fracking and well stack connector |
| US11242950B2 (en) | 2019-06-10 | 2022-02-08 | Downing Wellhead Equipment, Llc | Hot swappable fracking pump system |
| US11939832B2 (en) * | 2020-12-18 | 2024-03-26 | Baker Hughes Oilfield Operations Llc | Casing slip hanger retrieval tool system and method |
| US11920416B2 (en) | 2020-12-18 | 2024-03-05 | Baker Hughes Oilfield Operations Llc | Metal-to-metal annulus packoff retrieval tool system and method |
| CN113374436B (en) * | 2021-07-22 | 2022-02-15 | 盐城市煜洋石油机械有限公司 | Anticorrosion gas production wellhead assembly |
| US20230399908A1 (en) * | 2022-06-10 | 2023-12-14 | Fmc Technologies, Inc. | Wireline Pressure Control String with Pumpdown Assembly |
Family Cites Families (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2233077A (en) * | 1938-10-10 | 1941-02-25 | Barker | Well controlling apparatus |
| US2939534A (en) * | 1956-04-10 | 1960-06-07 | Cameron Iron Works Inc | Sealed telescopic connection |
| US2830666A (en) * | 1956-07-12 | 1958-04-15 | George A Butler | Combined sealing plug and tubing hanger |
| US4825945A (en) * | 1988-03-21 | 1989-05-02 | Cameron Iron Works Usa, Inc. | Wellhead valve |
| CA1290684C (en) * | 1988-12-01 | 1991-10-15 | Roderick D. Mcleod | Back pressure plug tool |
| US4923006A (en) * | 1989-08-07 | 1990-05-08 | Cameron Iron Works Usa, Inc. | Insulating support for tubing string |
| CA1281280C (en) * | 1989-09-26 | 1991-03-12 | Roderick D. Mcleod | Annular and concentric flow wellhead isolation tool and method of use thereof |
| US5515925A (en) * | 1994-09-19 | 1996-05-14 | Boychuk; Randy J. | Apparatus and method for installing coiled tubing in a well |
| US5785121A (en) * | 1996-06-12 | 1998-07-28 | Dallas; L. Murray | Blowout preventer protector and method of using same during oil and gas well stimulation |
| US5819851A (en) * | 1997-01-16 | 1998-10-13 | Dallas; L. Murray | Blowout preventer protector for use during high pressure oil/gas well stimulation |
| US5988274A (en) * | 1997-07-30 | 1999-11-23 | Funk; Kelly | Method of and apparatus for inserting pipes and tools into wells |
| US5988273A (en) * | 1997-09-03 | 1999-11-23 | Abb Vetco Gray Inc. | Coiled tubing completion system |
| US6209633B1 (en) * | 1997-12-17 | 2001-04-03 | Michael Jonathon Haynes | Apparatus and method for axially displacing a downhole tool or a tubing string in a well bore |
| US6012519A (en) * | 1998-02-09 | 2000-01-11 | Erc Industries, Inc. | Full bore tubing hanger system |
| US6234253B1 (en) * | 1998-11-30 | 2001-05-22 | L. Murray Dallas | Method and apparatus for well workover or servicing |
| US6145596A (en) * | 1999-03-16 | 2000-11-14 | Dallas; L. Murray | Method and apparatus for dual string well tree isolation |
| CA2275814C (en) * | 1999-06-21 | 2003-10-28 | L. Murray Dallas | Blowout preventer protector and setting tools |
| US6220363B1 (en) * | 1999-07-16 | 2001-04-24 | L. Murray Dallas | Wellhead isolation tool and method of using same |
| US6364024B1 (en) * | 2000-01-28 | 2002-04-02 | L. Murray Dallas | Blowout preventer protector and method of using same |
| US6510900B2 (en) * | 2001-02-08 | 2003-01-28 | L. Murray Dallas | Seal assembly for dual string coil tubing injection and method of use |
| US6595297B2 (en) * | 2001-02-23 | 2003-07-22 | L. Murray Dallas | Method and apparatus for inserting a tubing hanger into a live well |
| US6695064B2 (en) * | 2001-12-19 | 2004-02-24 | L. Murray Dallas | Slip spool and method of using same |
-
2003
- 2003-01-03 CA CA002415631A patent/CA2415631A1/en not_active Abandoned
- 2003-01-06 US US10/336,911 patent/US6918439B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US6918439B2 (en) | 2005-07-19 |
| US20040129429A1 (en) | 2004-07-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |