Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
423 words
In a method of drilling a wellbore into a hydrocarbon bearing formation or the like, the combination of steps comprising: mounting a plurality of generally vertically extending hydraulic piston and cylinder assemblies over a wellbore site; supporting a rotary table on the upper ends of said hydraulic piston and cylinder assemblies, whereby extension and retraction of said assemblies causes raising and lowering of said rotary table; attaching a first plurality of hydraulically actuated pipe gripping elements to said rotary table for rotation therewith; supporting another plurality of hydraulically actuated pipe gripping elements axially below said first plurality of pipe gripping elements, said second plurality of elements being generally held against axial and rotational movement when in the engaged position with said drill string; placing the initial portion of the drill string in said rotary table; actuating said first plurality of pipe gripping elements into engagement with said drill string, whereby said drill string is suspended by said rotary table and held against axial and rotary movement relative to said rotary table; connecting a rotary swivel to the upper end of said drill string, rotating said rotary table to thereby effect rotation of said drill string; lowering said drill string during said rotation by operating said hydraulic piston and cylinder assemblies, to thereby effect drilling of said wellbore by said drill string; flowing a drilling fluid through said swivel and drill string during rotation of said drill string; terminating rotation of said rotary table and flowing of said drilling fluid, discOnnecting said swivel from said drill string; actuating said second plurality of gripping elements, whereby said drill string is held against rotational and downward movement in said wellbore; deactuating said first plurality of pipe gripping elements, whereby said rotary table is disengaged from said drill string, raising said rotary table and placing an additional section of drill pipe in said rotary table; actuating said first plurality of gripping elements, whereby said additional section of drill pipe is held in said rotary table against rotational and downward movement relative thereto; lowering and rotating said rotary table with said additional section of drill pipe held therein to thereby make up said additional section of drill pipe with the upper end of said drill string; deactuating said second plurality of said pipe engaging elements, whereby said drill string is supported by said rotary table; reconnecting said swivel to the upper end of said drill string and resuming flow of drilling fluid therethrough; and resuming rotation and lowering of said rotary table, to thereby resume said drilling operation.
Claim 2
Dependent Claim
423 words
In a method of drilling a wellbore into a hydrocarbon bearing formation or the like, the combination of steps comprising: mounting a plurality of generally vertically extending hydraulic piston and cylinder assemblies over a wellbore site; supporting a rotary table on the upper ends of said hydraulic piston and cylinder assemblies, whereby extension and retraction of said assemblies causes raising and lowering of said rotary table; attaching a first plurality of hydraulically actuated pipe gripping elements to said rotary table for rotation therewith; supporting another plurality of hydraulically actuated pipe gripping elements axially below said first plurality of pipe gripping elements, said second plurality of elements being generally held against axial and rotational movement when in the engaged position with said drill string; placing the initial portion of the drill string in said rotary table; actuating said first plurality of pipe gripping elements into engagement with said drill string, whereby said drill string is suspended by said rotary table and held against axial and rotary movement relative to said rotary table; connecting a rotary swivel to the upper end of said drill string, rotating said rotary table to thereby effect rotation of said drill string; lowering said drill string during said rotation by operating said hydraulic piston and cylinder assemblies, to thereby effect drilling of said wellbore by said drill string; flowing a drilling fluid through said swivel and drill string during rotation of said drill string; terminating rotation of said rotary table and flowing of said drilling fluid, discOnnecting said swivel from said drill string; actuating said second plurality of gripping elements, whereby said drill string is held against rotational and downward movement in said wellbore; deactuating said first plurality of pipe gripping elements, whereby said rotary table is disengaged from said drill string, raising said rotary table and placing an additional section of drill pipe in said rotary table; actuating said first plurality of gripping elements, whereby said additional section of drill pipe is held in said rotary table against rotational and downward movement relative thereto; lowering and rotating said rotary table with said additional section of drill pipe held therein to thereby make up said additional section of drill pipe with the upper end of said drill string; deactuating said second plurality of said pipe engaging elements, whereby said drill string is supported by said rotary table; reconnecting said swivel to the upper end of said drill string and resuming flow of drilling fluid therethrough; and resuming rotation and lowering of said rotary table, to thereby resume said drilling operation.
Claim 3
Dependent Claim
112 words
The invention as claimed in claim 1 wherein said drill string is lowered in said wellbore by the steps of: terminating rotation of said drill string; actuating said second plurality of gripping elements, whereby said drill string is supported thereby; deactuating said first plurality of gripping elements, whereby said rotary table is disengaged from said drill string; raising said rotary table by extending said hydraulic piston and cylinder assemblies; actuating said first plurality of gripping elements and then deactuating said second plurality of gripping elements whereby said drill string is again supported by said rotary table; and resuming said rotation and lowering of said rotary table to thereby resume said drilling operation.
Claim 4
Dependent Claim
160 words
The invention as claimed in claim 1 including: a. terminating rotation of said rotary table; b. raising said rotary table while said drill string is supported thereby until the second section of drill pipe immediately below the first top section is adjacent said second plurality of gripping elements; c. actuating said second plurality of gripping elements into engagement with said second section of drill pipe, whereby said second section is held against rotation and said drill string is supported thereby; d. counter-rotating said rotary table to thereby unthread said top section of drill pipe from said second section; e. removing said uncoupled section of drill pipe from said rotary table; f. lowering said rotary table and actuating said first plurality of gripping elements into engagement with said drill string; g. deactuating said second plurality of gripping elements from engagement with said drill stem; h. and repeating said steps (b) through (g) until said drill string is removed from said wellbore.