Drill string heave compensator and latching apparatus

Abstract

A floating drilling derrick is provided with a split crown block and an opening to allow passage of a heave compensator cylinder which is secured to a lower traveling block. The piston rod of the compensator is secured to a drill string carrier. Coupling means are provided in the traveling block and carrier to selectively lock out the heave compensator. The traveling block and carrier are kept in proper orientation by guides thereon cooperating with guide rails on the derrick.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: .[. 
     
       1.  On a floating drilling platform of the type having a derrick, an upper crown block assembly having a plurality of sheaves mounted on the derrick, a lower traveling block assembly having a plurality of sheaves, powered cable means interconnecting the traveling block assembly and the crown block assembly, a rotary carrier for supporting the drill string below the traveling block, and a hydraulic heave compensator between the traveling block assembly and the rotary carrier; said crown block being formed with a vertical opening passing between said sheaves and said heave compensator comprising a central cylinder mounted on the traveling block assembly and arranged to pass through said vertical opening while the traveling block is selectively raised by the cable means, a piston in said cylinder having a rod projecting downwardly to said carrier, and coupling means for selectively coupling said carrier to the traveling block assembly when the piston is raised in the cylinder..]. .[. 
     
     
       2.  Apparatus according to claim 1, said crown block assembly including sets of primary sheaves spaced equidistantly on opposite sides of said vertical opening, said traveling block assembly including sets of secondary sheaves generally aligned below said sets of primary sheaves, and a transition sheave on one of said assemblies for guiding the cable means between said sets of sheaves..]. .[.3. Apparatus according to claim 2, said primary sets of sheaves lying in parallel planes and being coplanar with said secondary sheaves, and said transition sheave being directly between and at right angles to said primary sheaves..]. .[.4. Apparatus according to claim 1, said coupling means comprising a pair of parallel spaced plates on the traveling block assembly having aligned retainer pin openings, retainer pins, a tongue on said carrier having bores on opposite sides of said piston rod positionable between said spaced plates in alignment with said retainer pin openings, and means for reciprocating said retainer pins through said spaced retainer pin openings to lock said rotary carrier to said traveling block..]. .[.5. Apparatus according to claim 1 in which said rotary carrier and derrick have cooperating guide means for vertically guiding the carrier..]. .[.6. Apparatus according to claim 1 in which said traveling block assembly and derrick have cooperating guide means for vertically guiding the traveling block assembly..]. .[.7. Apparatus according to claim 1 in which said derrick has vertical parallel spaced guide rails, and respective guide means on the traveling block assembly and rotary carrier cooperating with said guide rails..]. .[.8. Apparatus according to claim 7 in which said coupling means comprises cooperating members on the traveling block assembly and rotary carrier which are maintained in operative orientation 
     
     
        relative to one another by said guide means..]. .Iadd.9.  For use on a floating drilling platform of the type having a derrick, apparatus comprising: an upper crown block assembly adapted to be mounted on the derrick, said crown block assembly including sets of primary sheaves located at opposite sides of a vertical opening through the crown block assembly and including a transition sheave, a lower traveling block assembly including sets of secondary sheaves, said primary sets of sheaves lying in parallel planes and being coplanar with said secondary sheaves, and said transition sheave being directly between and at right angles to said primary sheaves, the traveling block assembly and the crown block assembly being adapted to be interconnected by powered cable means, a rotary carrier for supporting the drill string below the traveling block, and a hydraulic heave compensator between the traveling block assembly and the rotary carrier comprising a central cylinder mounted on the traveling block assembly and arranged to pass through said vertical opening while the traveling block is selectively raised by the cable means, a piston in said cylinder having a rod projecting downwardly to said carrier, and coupling means for selectively coupling said carrier to the traveling block assembly when the piston is raised in the cylinder. .Iaddend. .Iadd.10. For use on a floating drill platform of the type having a derrick, apparatus comprising: an upper crown block assembly having a plurality of sheaves, a lower traveling block assembly having a plurality of sheaves, the traveling block assembly and the crown block assembly being adapted to be interconnected by powered cable means, a rotary carrier for supporting the drill string below the traveling block, and a hydraulic heave compensator between the traveling block assembly and the rotary carrier; said crown block assembly being formed with a vertical opening passing between said sheaves and said heave compensator comprising a central cylinder mounted on the traveling block assembly and arranged to pass through said vertical opening while the traveling block is selectively raised by the cable means, a piston in said cylinder having a rod projecting downwardly to said carrier, and coupling means for selectively coupling said carrier to the traveling block assembly when the piston is raised in the cylinder, said coupling means comprising a pair of parallel spaced plates on the traveling block assembly having aligned retainer pin openings, retainer pins, a tongue on said carrier having bores on opposite sides of said piston rod positionable between said space plates in alignment with said retainer pin openings, and means for reciprocating said retainer pins through said spaced retainer pin openings to lock said rotary carrier to said traveling block. .Iaddend.