Blow out preventer handling system
First Claim
1. A system for testing and installing a blow out preventer on a floating vessel having a moon pool and a derrick over the moon pool, the derrick having an opening through which a portion of the blow out preventer can be moved and having means for lowering it into the moon pool comprising,retractable rotary table support beams disposed over the moon pool supporting a rotary table for rotating a drill string during rotary drilling operations,means releasably connecting the rotary table to the rotary table support beams,retractable substructure beams below the rotary table,test stump meansmeans for positioning an upper section and a lower section of the blow out preventer on opposite sides of the longitudinal axis of the vessel, for placing the lower section of the blow out preventer on the test stump means and placing the upper section on the lower section,support shoulders extending from at least one of the upper and lower sections arranged to support the blow out preventer on the substructure beams,means operable to move the assembled blow out preventer through the derrick opening and space provided by the retracted substructure beams and over the moon pool,guide means operable to restrain swinging movement of the blow out preventer when moving it in the moon pool,whereby the upper section and the lower section of the blow out preventer can be positioned on opposite sides of the longitudinal axis of the vessel thereby minimizing forces due to the roll of the vessel, the upper section can be placed on the lower section and the blow out preventer assembled and tested on the test stump means and then moved through the derrick opening and space provided by the retracted rotary table support beams and over the moon pool and guided while being lowered until the support shoulders engage the retractable substructure beams, the rotary table support beams replaced and the rotary table connected to them, the upper section of the blow out preventer connected to the means to lower it, the blow out preventer lifted and the substructure beams retracted, and the blow out preventer then lowered in the moon pool.
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Accused Products
Abstract
A system for testing and installing a blow out preventer on a floating vessel and offshore drilling rigs, although the system may be used on other rotary drilling rigs, is disclosed. Retractable rotary table supporting beams are disposed over the moon pool and the rotary table is releasably connected to them. Retractable sub-structure beams are provided below the rotary table so that means provided to move the assembled blow out preventer can move it through an opening in the derrick and over the moon pool when the rotary beams are retracted. Retractable moon pool skid beams are provided which support the blow out preventer when skidded through the moon pool opening in the sub-structure.
In one aspect of the invention, the means connecting the rotary table to its support beams are self-aligning to that once the rotary table is aligned it can be removed and replaced without any further alignment. Also, support shoulders are provided on the main blow out preventer and lower riser section thereof which engage and are supported by the moon pool beams, so that the rotary support beams, rotary table and sub-structure support beams can be replaced and the blow out preventer hooked up to the riser, drill string or casing, the moon pool beams retracted and the blow out preventer lowered in the moon pool to the sea floor.
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Citations
14 Claims
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1. A system for testing and installing a blow out preventer on a floating vessel having a moon pool and a derrick over the moon pool, the derrick having an opening through which a portion of the blow out preventer can be moved and having means for lowering it into the moon pool comprising,
retractable rotary table support beams disposed over the moon pool supporting a rotary table for rotating a drill string during rotary drilling operations, means releasably connecting the rotary table to the rotary table support beams, retractable substructure beams below the rotary table, test stump means means for positioning an upper section and a lower section of the blow out preventer on opposite sides of the longitudinal axis of the vessel, for placing the lower section of the blow out preventer on the test stump means and placing the upper section on the lower section, support shoulders extending from at least one of the upper and lower sections arranged to support the blow out preventer on the substructure beams, means operable to move the assembled blow out preventer through the derrick opening and space provided by the retracted substructure beams and over the moon pool, guide means operable to restrain swinging movement of the blow out preventer when moving it in the moon pool, whereby the upper section and the lower section of the blow out preventer can be positioned on opposite sides of the longitudinal axis of the vessel thereby minimizing forces due to the roll of the vessel, the upper section can be placed on the lower section and the blow out preventer assembled and tested on the test stump means and then moved through the derrick opening and space provided by the retracted rotary table support beams and over the moon pool and guided while being lowered until the support shoulders engage the retractable substructure beams, the rotary table support beams replaced and the rotary table connected to them, the upper section of the blow out preventer connected to the means to lower it, the blow out preventer lifted and the substructure beams retracted, and the blow out preventer then lowered in the moon pool.
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6. A system for testing and installing a blow out preventer on an offshore drilling rig having a moon pool and a derrick over the moon pool, the derrick having an opening through which a portion of the blow out preventer can be moved and having means for lowering it into the moon pool comprising,
retractable rotary table supporting beams disposed over the moon pool supporting a rotary table for rotating a drill string during rotary drilling operations, and providing an additional opening below the opening in the derrick, means releasably connecting the rotary table to the rotary table support beams comprising co-acting, self-aligning anchor members connected to the retractable rotary table support beams and to the rotary table and arranged to self-align the rotary table upon connecting it to the rotary table support beams, means operable to move the assembled blow out preventer through the derrick opening and over the moon pool, whereby the rotary table and the rotary table supporting beams can be retracted from the moon pool, the blow out preventer moved through the openings and over the moon pool and lowered into the moon pool, the rotary table support beams replaced and the rotary table reconnected to them.
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9. A system for testing and installing a blow out preventer on a floating vessel having a moon pool and a derrick over the moon pool, the derrick having an opening through which a portion of the blow out preventer can be moved and having means for lowering it into the moon pool comprising,
retractable rotary table support beams disposed over the moon pool supporting a rotary table for rotating a drill string during rotary drilling operations, means releasably connecting the rotary table to the rotary table support beams, retractable substructure beams below the rotary table, test stump means, means for placing a lower section of the blow out preventer on the test stump means and placing an upper section of the blow out preventer on the lower section, support shoulders extending from at least one of the upper and lower sections arranged to support the blow out preventer on the substructure beams, means operable to move the assembled blow out preventer through the derrick opening and space provided by the retracted substructure beams and over the moon pool, guide means operable to restrain swinging movement of the blow out preventer when moving it in the moon pool, whereby the upper section and the lower section of the blow out preventer can be positioned on opposite sides of the longitudinal axis of the vessel thereby minimizing forces due to the roll of the vessel, the upper section can be placed on the lower section and the blow out preventer assembled and tested on the test stump means and then moved through the derrick opening and space provided by the retracted rotary table support beams and over the moon pool and guided while being lowered until the support shoulders engage the retractable substructure beams, the rotary table support beams replaced and the rotary table connected to them, the upper section of the blow out preventer connected to the means to lower it, the blow out preventer lifted and the substructure beams retracted, and the blow out preventer then lowered in the moon pool.
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11. The system of claim 17 where the means arranged to move the assembled blow out preventer through the opening in the derrick and the space provided by the retractable substructure beams and over the moon pool comprise,
skid beams having retractable portions extending over the moon pool, skids on the lower section of the blow out preventer slidable on the skid beams, and means operable to slide the skids on the skid beams.
Specification