US3330339A - Method of removing a wellhead assembly from the ocean floor - Google Patents

Method of removing a wellhead assembly from the ocean floor Download PDF

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Publication number
US3330339A
US3330339A US401480A US40148064A US3330339A US 3330339 A US3330339 A US 3330339A US 401480 A US401480 A US 401480A US 40148064 A US40148064 A US 40148064A US 3330339 A US3330339 A US 3330339A
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US
United States
Prior art keywords
pipe
drilling
vessel
ocean floor
wellhead assembly
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.)
Expired - Lifetime
Application number
US401480A
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English (en)
Inventor
Glenn D Johnson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shell USA Inc
Original Assignee
Shell Oil Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shell Oil Co filed Critical Shell Oil Co
Priority to US401480A priority Critical patent/US3330339A/en
Priority to GB42022/65A priority patent/GB1122004A/en
Priority to NO159940A priority patent/NO117070B/no
Priority to DK508665AA priority patent/DK108617C/da
Priority to BE670492D priority patent/BE670492A/xx
Priority to ES0318103A priority patent/ES318103A1/es
Priority to NL6512826A priority patent/NL6512826A/xx
Application granted granted Critical
Publication of US3330339A publication Critical patent/US3330339A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B7/00—Special methods or apparatus for drilling
    • E21B7/12—Underwater drilling
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/01—Risers
    • E21B17/012—Risers with buoyancy elements
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B29/00—Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
    • E21B29/12—Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground specially adapted for underwater installations
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK 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
    • E21B33/035—Well heads; Setting-up thereof specially adapted for underwater installations

Definitions

  • This invention relates to a method and apparatus for use after drilling an oil or gas well at an offshore location, and pertains more particularly to a method adapted to be carried out from a vessel at the surface of a body of water whereby a wellhead assembly positioned on the ocean floor may be retrieved and brought back to the vessel.
  • Deep water wells are generally drilled from vessels of varying designs, commonly known as drilling barges, vessels or platforms. Deep water wells are generally drilled by one of two methods. In one method the string of drill pipe extends downwardly from the drilling vessel to the drilling wellhead assembly, on the ocean floor, which is closed at the top by a circulation head with a flexible hose running from the circulation head back to the surface and to the drilling vessel so that drilling fluid may be circulated down the drill pipe, through the drill bit, and thence upwardly along the outside of the drill pipe, out the circulation head and up the flexible hose to the vessel again.
  • a large-diameter pipe known as a marine conductor pipe is put together and arranged to extend from the drilling wellhead assembly near the ocean floor to the vessel on the surface of the Water.
  • the drill string rotates within the conductor pipe with drilling fluid being circulated down through the drill pipe, through the bit at the bottom thereof, up the outside of the drill pipe within the well and thence upwardly through the annular space between the conductor pipe and the drill pipe, returning to the vessel in the conventional manner.
  • the present invention is concerned with retrieving, from an ocean floor location, apparatus used in either of the abovedescribed methods.
  • Another object of the present invention is to provide a method for removing a drilling wellhead assembly from the ocean floor without the use of explosives.
  • FIGURE 1 is a diagrammatic view taken in longitudinal projection and partly in cross section illustrating a floating vessel positioned at the surface of the ocean with an underwater wellhead drilling assembly positioned on the ocean floor;
  • FIGURE 2 is a longitudinal view taken partially in cross section illustrating a portion of the drilling wellhead assembly shown in FIGURE 1 at a time when concentric strings of pipe extending downwardly from the drilling wellhead assembly have been sheared so that the drilling wellhead assembly can be returned to the vessel at the surface;
  • FIGURE 3 is a longitudinal diagrammatic view illustrating one form of a tool which may be employed by the method of the present invention.
  • the present invention provides a method for retrieving a tubular underwater drilling wellhead assembly from the ocean floor and pulling it back to a drilling vessel on the ocean surface.
  • the wellhead assembly is provided with at least two concentric pipe strings which extend into the ocean floor and at least one and often both are cemented therein.
  • the wellhead assembly is also provided with closure means for closing the innermost pipe string and disconnect means on the outermost pipe string.
  • a separation is formed in the innermost pipe string of the wellhead assembly at a point below the ocean floor, after which the innermost pipe string is closed at a point above the separation.
  • a pressure fluid is applied from the vessel into the innermost pipe string below the closed pipe and thence through the separation point in the innermost pipe to the space between the innermost pipe string and the outer pipe string so as to apply a verticallydirected hydraulic lift to the drilling wellhead assembly, after which the drilling wellhead assembly can be hoisted back to the vessel.
  • the hydraulic lift from below the wellhead assembly is applied at the same time that a hoisting lift is applied from the vessel itself by suitable hoist means.
  • a drilling vessel, barge or platform is generally represented by numeral 11.
  • the drilling vessel is of any suitable type preferably, as illustrated, floating on the surface of a body of water 12 and being substantially fixedly positioned over the preselected drilling location by suitable vesselpositioning means or by being anchored to the ocean floor 13 by suitable anchors (not shown) connected to anchor lines 14 and 15, Equipment of this type may be used when carryingon well drilling operations in water depths varying from about 100 to 1500 feet or more.
  • the drilling vessel is equipped with a suitable derrick 16'as well as other auxiliary equipment needed during the drilling of a well, such as a hoist system 17, rotary table 18, power swivel 19 and mud pump 20.
  • the derrick 16 may be positioned over a drilling slot or well which extends vertically through the vessel in a conventional manner.
  • the slot of the vessel may be centrally located or extend in from one edge.
  • drilling operations may be carried out over the side of the vessel without the use of a slot, as from a portion of the deck of the vessel which is cantilevered out over one end.
  • the equipment of the present invention may also be used when drilling a well from a suitable operational base positioned above the surface of the water, such for example, as from a drilling barge having legs extending from the ocean floor, or from a platform permanently positioned on the ocean floor.
  • FIGURE 1 A typical underwater wellhead drilling assembly is illustrated in FIGURE 1 as comprising a base member 21 which is positioned on the ocean floor 13 and is fixedly secured to a conductor pipe or large-diameter well casing 22a by means of a ball-and-socket joint 23.
  • the drilling wellhead assembly is removably secured to the top of a foundation pile 24 which in turn is secured to the top of the ball and socket joint 23.
  • the drilling wellhead assembly is secured to the top of a casinghead 25 which in turn is mounted on the top of the foundation pile 24.
  • the combined casing 22, foundation pile 24 and casinghead 25 form a continuous tubular member or pipe extending up from the ocean floor through which drilling operations are conducted.
  • the drilling wellhead assembly illustrated includes a detachable wellhead connector or drilling bonnet 27 of any suitable type well known to the art.
  • Fixedly secured above the wellhead connector 27 is a ram-type blowout preventer unit 28, a bag-type blowout preventer unit 29, a flexible joint 30, a remotely-operable quick-disconnect coupling and sealing apparatus 31, and a sectionalized marine conductor pipe assembly 32 extending to the vessel 11 at the surface 12.
  • the remotely-operable quick-disconnect coupling'and sealing apparatus 31 may also be designated hereinbelow 'as a wellhead connector.
  • auxiliary pipes 33 and 40 Passing down alongside the wellhead connector 31 (FIGURE 1) are a pair of small-diameter auxiliary pipes 33 and 40 which may be readily disconnected by any suitable type of pull-out connector, as at points 41 and 42.
  • the wellhead connector 31 is adapted to pass downwardly over and latch onto a tubular member 43 which is fixedly mounted atop the flexible joint 30 in this particular arrangement.
  • the connector 31 is provided with suitable laterally-extending latches 44 adapted to move inwardly. to engage the tubuiar member 43 positioned within the,
  • the upper end of the connector 4 is provided with an internally projecting landing surface or seating shoulder 45.
  • the drilling wellhead assembly and base structure described hereinabove may be lowered as a unit from the vessel 11 at the surface of the ocean, with the largediameter well casing 22 extending below the base member 21 into a hole 46 formed or drilled in the ocean floor 13. Generally, a certain amount of cement 47 is positioned in the hole 46 to secure the base member 21 to the ocean floor.
  • the foundation pile 24 may be 30 inches in diameter with the next innermost pipe or well casing 22 being 24 inches in diameter.
  • a smaller-diameter string of well casing, say a 13% inch string of pipe 50, is hung from the casinghead 25 with the lower end of the pipe or a continuation thereof extending downwardly into the well 46 where it is cemented.
  • additional strings of casing may be positioned within the casing string 50, such for example, as a 9% inch string of casing (not shown) which may be the size of the next string of pipe hung in the well.
  • the outermost well casing 22 below the base member 21 is formed in two sections, 22 and 22a, respectively.
  • the two sections of casing 22 and 22a meet at a point 53 within the collar 51.
  • the upper section of casing 2201 may be lifted out of the collar 51.
  • the collar 51 is normally positioned at a pre-selected distance, say 25 feet, below the the surface of the ocean floor 13.
  • the casing 22 may be provided with a wing-type centralizer 54 for centering the smaller diameter string of casing 50 therein.
  • the object of the present invention is to provide a method of separating the various concentric strings of pipe at a point below the ocean floor after a well has been plugged so that there is no structure extending above the ocean floor to become a hazard to fishing.
  • at least one of two concentric strings of pipe extending into the ocean floor is provided with a tension-actuated disconnect joint while an inner concentric pipe is cut by means of any suitable type of pipe or casing cutter.
  • One suitable form of pipecutting mechanism is diagrammatically shown in FIG- URE 3 which illustrates a pipe cutter 55 having radially extendible cutting elements 56.
  • the pipe cutter 55 is fixedly secured to the lower end of a small diameter pipe string 57 which extends upwardly to the vessel at the surface.
  • the pipe cutting head 55 may be automatically rotatable at the lower end of the pipe string 57 or the pipe string 57 itself may extend through the rotary table on the vessel 11 on the surface and be rotated in a manner well known to the art. Since there is some vertical motion of the vessel 11 due to wave action at the surface of the ocean, a stop member 58 is provided on the pipe string 57 which stop member is adapted to seat on landing surface or shoulder 45 above the disconnect joint 31 of the assembly shown in FIGURE 1. The spacing between the cutter head 55 and the stop member 58 should be at least equal to the distance between the shoulder 45 and the level at which it is desired to cut off the pipe within the well.
  • FIGURE 1 The start of the pipe cutting operation is shown in FIGURE 1 wherein the running string 57 has been'run through the rotary table 18 until the stop member 58 carried on the running string 57 is seated on shoulder 45.
  • running string 57 is positioned at a fixed distance below the shoulder 45.
  • the stop member 58 remains seated on the shoulder 45 during the cutting operation although the vessel 11 on the surface may rise and fall.
  • the upper end of the running string 57 is free to slide up and down in the bushing of the rotary table 18 as it is rotated.
  • an upward force is applied to the underwater assembly to cause the shear pins 52 to shear thus allowing the entire assembly, including the base member 21, to be lifted off the ocean floor, as illustrated in FIGURE 2, and returned to the vessel.
  • the lifting operation may be carried out by means of the hoist system 17 of the drilling vessel which would lift the marine conductor pipe 32 one section at a time and disassemble at the vessel until all the components of the drilling assembly and surface warhead structure had been retrieved and stored on the vessel.
  • fiuid pressure may be utilized as the lifting force to cause the shear pins 52 to break and free the underwater structure from the ocean floor.
  • the pipe ram 60 (FIGURE 2) of the blowout preventer 28 or the bag within the blowout preventer 29 (FIGURE 1) may be closed around the pipe string 57. Thereafter, hydraulic pressure fluid is applied through pipe string 57 from the vessel 11 by means of pump 20. With the pipe rams 60 closed and suitable communication having been provided through the wall of the innermost pipe 50, in this instance by means of the cut that has been made, the closed upper end between casing strings 22 and 50 and the closed pipe rams 60 serve as a piston against which pressure fluid may be applied when it is pumped down the running string 57.
  • a pump pressure of say 1,000 pounds is able to produce the equivalent of a 400,000 pound thrust tending to move the entire underwater structure upwardly so as to shear the shear pins 52.
  • the structure may be lifted to the vessel at the surface as described hereinabove. If desired, a combination of the hydraulic thrusting force and a mechanical hoisting froce from the hoist system of the vessel may be utilized simultaneously to shear the pins 52 if necessary.
  • the above operations may also be carried out without the use of the running pipe string 57 as a pressure conduit if operations are carried out in the following manner.
  • the upper blind rams of the blowout preventer 28 would be closed after the pipe cutter and lowering pipe string 57 have been removed to the vessel.
  • pressure fluid would be pumped from the vessel down conduit 39 and into the blowout preventer 28 (FIGURE 1) below the blind rams thereof with the result that pressure fluid would again enter the space between the two pipe strings 22 and 50 and exert a force causing the shear pins 52 to shear.
  • the abovedescribed operations can be carried out successfully if it is assumed that the remotely-operable quick-disconnect coupling and sealing apparatus 31 is of the type that stays positively locked at all times during drilling operations and the subsequent recovery of the equipment. If on the other hand, the wellhead connector 31 is merely a sealing element throughout drilling operations which may be readily pulled. apart under a predetermined pressure, say 5,000 pounds, it is apparent that any upward pull on the marine conductor pipe assembly 32 from the surface would cause the assembly to part at the connector 31 Without the equipment therebelow being recovered.
  • the tool can be run into the well assembly so as to cut the pipe by means of the cutter 55, apply pressure to the space below the pipe rams 60 (FIGURE 2) after they had been closed to cause or aid in the rupture of the shear pins 52, and subsequently be employed to lift the entire assembly ofl the ocean floor with the pipe rams 60 being closed over the stop member 64, as shown in FIGURE 2.
  • stop member 64 may be employed instead of stop member 64 so that together with the pipe string 57 they could be utilized to lift the entire assembly off the ocean floor.
  • said pipe string is closed by closing the blowout preventer of said assembly.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Mechanical Engineering (AREA)
  • Earth Drilling (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
US401480A 1964-10-05 1964-10-05 Method of removing a wellhead assembly from the ocean floor Expired - Lifetime US3330339A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US401480A US3330339A (en) 1964-10-05 1964-10-05 Method of removing a wellhead assembly from the ocean floor
GB42022/65A GB1122004A (en) 1964-10-05 1965-10-04 Method of retrieving an underwater drilling wellhead assembly from the floor of a body of water
NO159940A NO117070B (enrdf_load_html_response) 1964-10-05 1965-10-04
DK508665AA DK108617C (da) 1964-10-05 1965-10-04 Fremgangsmåde til tilbagehentning af et undervandsborehuludstyr fra havets bund.
BE670492D BE670492A (enrdf_load_html_response) 1964-10-05 1965-10-04
ES0318103A ES318103A1 (es) 1964-10-05 1965-10-04 Un metodo de recuperar del fondo de una masa de agua un conjunto tubular de cabeza de pozo de perforacion subacuatica.
NL6512826A NL6512826A (enrdf_load_html_response) 1964-10-05 1965-10-04

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US401480A US3330339A (en) 1964-10-05 1964-10-05 Method of removing a wellhead assembly from the ocean floor

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US3330339A true US3330339A (en) 1967-07-11

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US401480A Expired - Lifetime US3330339A (en) 1964-10-05 1964-10-05 Method of removing a wellhead assembly from the ocean floor

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US (1) US3330339A (enrdf_load_html_response)
BE (1) BE670492A (enrdf_load_html_response)
DK (1) DK108617C (enrdf_load_html_response)
ES (1) ES318103A1 (enrdf_load_html_response)
GB (1) GB1122004A (enrdf_load_html_response)
NL (1) NL6512826A (enrdf_load_html_response)
NO (1) NO117070B (enrdf_load_html_response)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3421580A (en) * 1966-08-15 1969-01-14 Rockwell Mfg Co Underwater well completion method and apparatus
US3461958A (en) * 1967-01-16 1969-08-19 Cicero C Brown Methods and apparatus for installation and removal of preventer stacks in offshore oil and gas wells
US3498374A (en) * 1967-11-14 1970-03-03 Rockwell Mfg Co Underwater safety connector
US3603385A (en) * 1969-02-04 1971-09-07 Offshore Systems Inc Method and apparatus for removably coupling a blowout preventer stack to an underwater wellhead casing
US3638721A (en) * 1969-12-10 1972-02-01 Exxon Production Research Co Flexible connection for rotating blowout preventer
US3666009A (en) * 1970-01-23 1972-05-30 Gulf Oil Corp Method and apparatus for shutting in offshore wells
US4126183A (en) * 1976-12-09 1978-11-21 Deep Oil Technology, Inc. Offshore well apparatus with a protected production system
WO1998058152A1 (en) * 1997-06-17 1998-12-23 Sofitech N.V. Method and apparatus for drilling subsea wells
US6330919B1 (en) * 1996-03-08 2001-12-18 Smith International, Inc. Method of removing wellhead assemblies and cutting assembly for use therein
US6702031B2 (en) 2001-02-02 2004-03-09 Baker Hughes Incorporated Anchoring device removal method and apparatus
US20050145389A1 (en) * 2003-08-12 2005-07-07 Steve Barrow Casing cutter
US20150376907A1 (en) * 2014-06-30 2015-12-31 Cameron International Corporation Platform to Service a Blowout Preventer

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2988145A (en) * 1956-12-03 1961-06-13 Baker Oil Tools Inc Well bore drilling and cementing apparatus
US3115933A (en) * 1960-08-10 1963-12-31 Shell Oil Co Apparatus for installing and retrieving equipment from underwater wells
US3145775A (en) * 1958-01-30 1964-08-25 Jersey Prod Res Co Method and apparatus for conducting offshore drilling operations
US3177942A (en) * 1958-01-27 1965-04-13 Shell Oil Co Well head assembly with telescoping tubing
US3186486A (en) * 1959-02-24 1965-06-01 Mcevoy Co Well completion
US3195638A (en) * 1959-08-03 1965-07-20 Cameron Iron Works Inc Submarie wellhead apparatus
US3259191A (en) * 1958-05-05 1966-07-05 Ross A Mcclintcck Subsea blowout prevention and landing apparatus

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2988145A (en) * 1956-12-03 1961-06-13 Baker Oil Tools Inc Well bore drilling and cementing apparatus
US3177942A (en) * 1958-01-27 1965-04-13 Shell Oil Co Well head assembly with telescoping tubing
US3145775A (en) * 1958-01-30 1964-08-25 Jersey Prod Res Co Method and apparatus for conducting offshore drilling operations
US3259191A (en) * 1958-05-05 1966-07-05 Ross A Mcclintcck Subsea blowout prevention and landing apparatus
US3186486A (en) * 1959-02-24 1965-06-01 Mcevoy Co Well completion
US3195638A (en) * 1959-08-03 1965-07-20 Cameron Iron Works Inc Submarie wellhead apparatus
US3115933A (en) * 1960-08-10 1963-12-31 Shell Oil Co Apparatus for installing and retrieving equipment from underwater wells

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3421580A (en) * 1966-08-15 1969-01-14 Rockwell Mfg Co Underwater well completion method and apparatus
US3461958A (en) * 1967-01-16 1969-08-19 Cicero C Brown Methods and apparatus for installation and removal of preventer stacks in offshore oil and gas wells
US3498374A (en) * 1967-11-14 1970-03-03 Rockwell Mfg Co Underwater safety connector
US3603385A (en) * 1969-02-04 1971-09-07 Offshore Systems Inc Method and apparatus for removably coupling a blowout preventer stack to an underwater wellhead casing
US3638721A (en) * 1969-12-10 1972-02-01 Exxon Production Research Co Flexible connection for rotating blowout preventer
US3666009A (en) * 1970-01-23 1972-05-30 Gulf Oil Corp Method and apparatus for shutting in offshore wells
US4126183A (en) * 1976-12-09 1978-11-21 Deep Oil Technology, Inc. Offshore well apparatus with a protected production system
US6330919B1 (en) * 1996-03-08 2001-12-18 Smith International, Inc. Method of removing wellhead assemblies and cutting assembly for use therein
US6554073B2 (en) * 1996-03-08 2003-04-29 Smith International, Inc. Method and apparatus for removing wellhead assemblies
GB2341626A (en) * 1997-06-17 2000-03-22 Sedco Forex International Inc Method and apparatus for drilling subsea wells
WO1998058152A1 (en) * 1997-06-17 1998-12-23 Sofitech N.V. Method and apparatus for drilling subsea wells
US6702031B2 (en) 2001-02-02 2004-03-09 Baker Hughes Incorporated Anchoring device removal method and apparatus
US20050145389A1 (en) * 2003-08-12 2005-07-07 Steve Barrow Casing cutter
US7090019B2 (en) * 2003-08-12 2006-08-15 Oceaneering International, Inc. Casing cutter
US20150376907A1 (en) * 2014-06-30 2015-12-31 Cameron International Corporation Platform to Service a Blowout Preventer
US9689233B2 (en) * 2014-06-30 2017-06-27 Cameron International Corporation Platform to service a blowout preventer

Also Published As

Publication number Publication date
NO117070B (enrdf_load_html_response) 1969-06-30
ES318103A1 (es) 1965-12-16
GB1122004A (en) 1968-07-31
DK108617C (da) 1968-01-15
NL6512826A (enrdf_load_html_response) 1966-04-06
BE670492A (enrdf_load_html_response) 1966-04-04

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