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
  • E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
  • E21B41/10—Guide posts, e.g. releasable; Attaching guide lines to underwater guide bases
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T403/00—Joints and connections
  • Y10T403/70—Interfitted members
  • Y10T403/7009—Rotary binding cam or wedge

Definitions

• the present invention relates to an activation mechanism for the release of a guidepost from a seabed structure, which guidepost includes a tubular main body, an operating means at the upper end of the main body, a locking mechanism at the lower end of the main body to enable attachment to the seabed structure, and an interconnecting device, arranged inside the tubular main body, connecting the operating means to the locking mechanism in order to be able to activate the locking mechanism from the top of the guidepost, as required.
• a guideline ends in a guidepost that is secured to and projects from the seabed structure.
• the guideposts are used to locate and orient components on subsea bases during oil drilling operations or oil production, or to locate modules on top of each other.
• a guide base is normally arranged around the conductor housing of a well that is drilled.
• the guide base has guideposts and these are used to position a blowout preventer BOP on top of the wellhead.
• Guideposts can also be used to install and position other modules, for example to guide and position a lower riser package on a blowout preventer, or an emergency disconnect package on a workover blowout preventer.
• Such guideposts establish a coarse alignment between the equipment and the wellhead and create vertical stability within the system in order to be able to make connection with the wellhead. Final alignment is performed by a connector making up the connection.
• On smaller components or modules only two guideposts are normally used. Recently, only two guideposts are more often used even on larger modules, such as manifolds for example.
• Traditionally, often four guidelines and four guideposts have been used during a lowering and landing operation.
• the guideposts When it comes to the length of the guideposts, they can never project above a protecting structure when not in use.
• the guideposts are either divided in two with a permanent part that ends below the top of the protecting structure and a contemporary post is put on top of that and extends above the structure, or the post can be lowered down until it has arrived below the structure when not in use, or that they are completely removed.
• the guideposts would then be used as kind of a tool, i.e. one could move them around between respective seabed structures that are stationary deployed on predetermined places, as desired, until the job is done and then have the guideposts retrieved.
• Such new generation guideposts can in some situations be as long as 17 meters.
• the guideposts will project above the bottom structure and will be a hazard for fish nets etc if they remain on the seabed structure, and consequently need to be removed.
• This prior art solution is normally based on locking means that are operated or maneuvered at same high as the locking mechanism is located, i.e. in the lower end of the of the guidepost.
• This level a lot of other equipment and components are present, which also make this difficult accessible with an ROV and associated tool for the maneuvering of the locking mechanism itself when the guidepost is to be fixed to the seabed structure.
• an activation mechanism for the release of a guidepost from a seabed structure of the introductory said kind which operating means includes a rotatable outer sleeve arranged to transform a rotary motion to either a lifting or lowering motion of the interconnecting device, which in turn either lifts or lowers an activation means that actuates at least one locking pawl to be pulled inwards or pushed outwards beyond the diametrical dimension of the guidepost in order to release or make engagement with a groove or ledge on the seabed structure.
• the rotatable outer sleeve of the operating means includes a substantially vertically extending slit that receives a pin in direct connection with an inner sleeve part that is connected to the interconnecting device, and that the upper end part of the guidepost is located partly between the inner and outer sleeve, which end part is provided with a slanting groove therein through which the pin extends between the two sleeves and is thus able to transform said rotary motion to said lifting or lowering motion of said interconnecting device.
• the interconnecting device can be in the form of a rod extending between the inner sleeve and the locking mechanism, said rod being supported at one or more locations against the inner wall of the guidepost.
• the rod of the interconnecting device can be loosely connected to the inner sleeve such that a limited freedom of motion is present between the sleeve and the rod, such freedom of motion being determined by means of a nut and a back-off nut, and in addition, the inner sleeve is rotatable about the rod.
• the lower end of the rod of the interconnecting device includes one or more actuating arms that are fixedly connected to the rod, which at least one actuating arm extends in a substantially radial direction relative to the tubular main body.
• each individual locking pawl of the locking mechanism can be directly actuatable by the respective actuating arm.
• each individual locking pawl can include a slotted track that cooperates with corresponding pin on an activating arm, where each locking pawl being pivotable supported on an axle pin which is such located that when the rod, including the activating arms, are lowered down, the locking pawls pivot outwards and beyond the diametric dimension of the guidepost for the mentioned engagement or abutment with a groove or ledge on the seabed structure.
• the lower end of the guidepost includes a stop pin that each individual locking pawl rests against in its completely deployed position, where each stop pin being a pin having rupture nicks in case an emergency situation should occur, in order to be able to retract the locking pawls such that the guidepost can be retrieved to the surface.
• the lower end of the guidepost includes a stainless steel contact tip for safe transfer of electric charges to offer anodes.
• the locking mechanism is an automatic acting locking mechanism which is able to lock the lower end of the guidepost to the seabed structure, where each pawl, when it is in deployed position, is forced inwards when the pawl hits a ledge, and the pawl thereafter falls out again when passing the ledge, which freedom of motion between the rod and the inner sleeve part enables this.
• the freedom of motion between the rod and the inner sleeve part is limited by a ledge on the rod and a nut threaded onto a pin end in the extension of the rod, which pin end fits through an aperture in the bottom of the inner sleeve part.
• Fig. 1 shows in perspective view a guidepost which has an activating
• Fig. 2 shows an elevation view of an upper end of the guidepost including an operating means
• Fig. 3 shows a longitudinal sectional view through the upper end shown in fig. 2, but viewed from opposite side,
• Fig. 4 shows a section corresponding to that shown in fig. 3, but having the inner sleeve removed
• Fig. 5 shows a longitudinal section through the lower part of the guidepost shown in fig. 1 , in a situation where the locking mechanism is inoperative
• Fig. 6 shows a longitudinal sectional view through the lower part of the guidepost shown in fig. 1 , in a situation where the locking mechanism is in active locking position
• Fig. 7 shows a situation where the lower end is complete and the locking mechanism in active position.
• fig. 1 that in general shows a complete guidepost 1 that houses an activation mechanism which is specially designed to enable locking of the guidepost 1 to a structure located on the seabed, such as a seabed construction.
• the guidepost 1 is in the form of a tubular main body 1 a forming a housing 1 a that partly surrounds the activation mechanism itself.
• the activation mechanism is not entirely shown in any figures, but parts thereof are shown on each figure and consequently is a compound mechanism consisting of many parts or components.
• the activation mechanism includes an operating means 2 which is arranged in the upper end of the main body 1 a, and a locking mechanism 3 that is arranged in the lower end of the main body 1 a.
• the locking mechanism 3 is adapted for fixed, or releasable, attachment to the seabed structure.
• the locking mechanism 3 includes an interconnecting device 4 provided internally of the tubular main body 1 a connecting the operating means 2 with the locking mechanism 3 in order to be able to activate the locking mechanism 3 from the top of the guidepost 1 , as desired.
• the operating means 2 includes a rotatable sleeve 2a which is able to translate a rotary motion to either an elevating or lowering motion of the interconnecting device 4.
• the interconnecting device 4 in turn elevates or lowers an activation means 4a that influence on at least one locking pawl 3a, and the influence takes place in such way that the tip 3a' of the locking pawl 3a is run outwards beyond the diametric dimension D of the guidepost 1 in order to be able to make engagement with, or abutment with, a groove or a ledge on the seabed structure.
• the rotatable outer sleeve 2a of the operating means 2 is provided with a substantially vertically extending recess or slit 2b in the wall thereof.
• the slit 2b is in turn adapted to receive a pin 2c that is in direct connection with an inner sleeve part 2d.
• the inner sleeve part 2d is in turn loosely connected to the elevating and lowering interconnecting device 4.
• the upper end part 1 b of the guidepost 1 is partly located between the inner and outer sleeve 2a, 2d and is securely screwed to the tubular main body 1 a by means of threaded connections 5. This means that the upper end part 1 b of the guidepost 1 is rotationally stiff in respect of the housing itself or the tubular main body 1 a.
• the slit 1 b' ends in the "upper" end in a small recess 1 b", in which the pin 2c may rest when the pin is in its upper position. This results in that a little additional force is necessary to bring the pin 2c out of the recess 1 b", i.e. out of its own “resting position” or stand by position. This is to prevent unintended activation of the entire activation mechanism and thereby the locking
• the outer sleeve 2a can be engaged by a tool (not shown) that embraces the sleeve 2a and grips hold on the sleeve at the same time as the tool is able to make revolution of the sleeve 2a.
• the interconnecting device 4 is made up by the activation means 4a and a rod 4b extending between the locking mechanism 3 and the inner sleeve 2d.
• the rod 4b is supported on several locations by means of journal blocks 8 resting against the inner wall of the guidepost 1 . It is to be understood, however, that the journal blocks 8 only have their functions during the assembly of the guideposts 1 and otherwise do not have any function. This is due to the long lengths of the guideposts 1 , up to 17 meters, or more, combined with the slenderness of the rod 4b that the blocks 8 support.
• the rod 4b terminates upwardly in a narrower pin end 4c having a threaded portion 4c'.
• the rod 4b of the interconnecting device 4 is in axial direction loosely connected to the bottom 2e of the inner sleeve 2d, such that a limited freedom of motion is present between the sleeve 2d and the rod 4b.
• the freedom of motion is defined by means of a ledge 4d on the rod 4b in combination with a nut 6a and a lock nut 6b which is tightened such that the pin end 4c receives a certain stroke length relative to the bottom 2e of the inner sleeve 2d.
• the sleeve 2d is rotatable about the pin end 4c of the rod 4b.
• a washer 6c is located between the nut 6a and the bottom 2e.
• the rod 4b of the interconnecting device 4 has one or more activation arms 4e in its lower end, which arms are fixedly connected to the rod 4b.
• Each activation arm 4e extends in a substantially radial direction relative to the tubular main body 1 a.
• each individual locking pawl 3a on the locking mechanism 3 are directly actuatable by an activation arm 4e. This takes place in such a way that each individual locking pawl 3a includes a slit groove 3a" that interact with corresponding pin 4e' on an activation arm 4e.
• Each locking pawl 3a is in turn rotatable supported on an axle journal 3b, which is such located that when the rod 4b, including the activation arms 4e, is lowered, the locking pawls 3a are pivoted outwards.
• the tip 3a' of the locking pawl 3a passes beyond the diametric dimension D of the guidepost 1 such that the tips 3a' of the locking pawls 3a can make the engagement with a groove, or abutment against a ledge on the subsea structure.
• the lower end portion 1 c of the guidepost 1 can include locking pins 1 c', against which the individual locking pawls 3a, in their fully deployed position, can rest.
• Each locking pin 1 c' is a pin with one or more fracture marks 1 c" in case an emergency situation should occur, in order to be able to retract the locking pawls 3a, such that the guidepost 1 can be released and retrieved to the surface.
• the lower end portion 1 c of the guidepost 1 can include a stainless steel contact tip 7 for safe transfer of electric charges to offer anodes that can be deployed on suitable locations to prevent substantial corrosion.
• the locking mechanism 3 is such arranged that the mechanism acts as an automatic locking mechanism that is able to lock the lower part 1 c of the guidepost 1 to the subsea structure, i.e. to a groove or a ledge or similar. This takes place when the guidepost 1 is landed in a prepared and matching opening in the seabed structure.
• each pawl 3a if in a deployed position, will be forced inwards when the pawl 3a hits the ledge. Thereafter the pawl 3a is deployed again when the pawl has passed the ledge.

Landscapes

• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mutual Connection Of Rods And Tubes (AREA)
• Quick-Acting Or Multi-Walled Pipe Joints (AREA)
• Accommodation For Nursing Or Treatment Tables (AREA)
• Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)
• Earth Drilling (AREA)

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Citations (5)

Family Cites Families (5)

• 2011
  • 2011-11-25 NO NO20111634A patent/NO333163B1/no unknown
• 2012
  • 2012-11-21 WO PCT/NO2012/050229 patent/WO2013077741A1/en active Application Filing
  • 2012-11-21 GB GB1408004.8A patent/GB2510746A/en not_active Withdrawn
  • 2012-11-21 MX MX2014005937A patent/MX2014005937A/es not_active Application Discontinuation
  • 2012-11-21 US US14/359,865 patent/US20140334872A1/en not_active Abandoned
  • 2012-11-21 BR BR112014012535A patent/BR112014012535A2/pt not_active IP Right Cessation
  • 2012-11-21 AU AU2012341138A patent/AU2012341138A1/en not_active Abandoned
  • 2012-11-21 AP AP2014007707A patent/AP2014007707A0/xx unknown

Patent Citations (5)

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