Stabilization of well lift frame

1. A lift frame stabilizer comprising:

a stabilizer body defining a front, a back, a top, a bottom, and first and second opposing sides;

a mount connected to the front of said stabilizer body and arranged for connection to an offshore lift frame;

a first extension arm connected to said first side of said stabilizer body and movable with respect to said stabilizer body between a retracted position and an extended position;

a first engagement mechanism carried at a distal end of said first extension arm and arranged for coupling to a vertically-oriented first rail so as to be vertically movable with respect to said first rail;

a second engagement mechanism coupled to said second side of said stabilizer body and arranged for coupling to a vertically-oriented second rail so as to be movable with respect to said second rail; and

a drive mechanism carried by said stabilizer body and arranged to move said extension arm between said retracted position, in which said first and second engagement mechanisms are not captured by said first and second rails, and said extended position, in which said first and second engagement mechanisms are vertically movably captured between said first and second rails.

2. The lift frame stabilizer of claim 1 further comprising:

a second extension arm connected to said second side of said stabilizer body and movable between a retracted position and an extended position, said second engagement mechanism carried at a distal end of said second extension arm, said drive mechanism arranged to move said second extension arm between said retracted and extended positions.

3. The lift frame stabilizer of claim 2 wherein:

said drive mechanism is arranged to simultaneously move both said first and second extension arms between said respective retracted and extended positions.

4. The lift frame stabilizer of claim 3 wherein said drive mechanism comprises:

an actuator;

a lead screw rotatable by said actuator; and

a carriage drivable by said lead screw, said carriage being coupled to said first extension arm for positioning thereof.

5. The lift frame stabilizer of claim 1 wherein said first engagement mechanism comprises:

a side roller rotatively mounted to a side roller carrier assembly;

a front roller rotatively mounted to a front roller carrier assembly; and

a back roller rotatively mounted to a back roller carrier assembly.

6. The lift frame stabilizer of claim 5 wherein said first engagement mechanism further comprises:

a base plate defining a planar surface, said side roller carrier assembly mounted to said base plate;

a wedge assembly coupled to said base plate so as to be movable in a perpendicular direction with respect to said planar surface, said wedge assembly having forward- and rearward-facing beveled driving surfaces with respect to said planar surface;

a rearward-facing beveled driven surface formed on said front roller carrier assembly slidingly captured at said forward-facing beveled driving surface of said wedge assembly; and

a forward-facing beveled driven surface formed on said rear roller carrier assembly slidingly captured at said rearward-facing driving beveled surface of said wedge assembly.

7. The lift frame stabilizer of claim 6 wherein said first engagement mechanism further comprises:

a table, said front and rear roller carrier assemblies slideably captured by said table.

8. The lift frame stabilizer of claim 7 wherein:

said forward- and rearward-facing beveled driving surfaces of said wedge assembly and said table each have a T-slot formed therein for slideably capturing said front and rear roller carrier assemblies.

9. The lift frame stabilizer of claim 6 wherein said first extension arm comprises:

a guide slidingly coupled to said stabilizer body;

a rod connected between said drive mechanism and said wedge assembly; and

a spring coupled between said drive mechanism and said base plate.

10. A stabilized well lift frame system comprising:

a lift frame arranged for suspension from a derrick on an offshore platform or vessel and for carrying well equipment;

vertically-oriented first and second stabilization rails mounted to said offshore platform or vessel in proximity to said lift frame; and

a stabilizer disposed between said first and second rails and coupled to said lift frame, said stabilizer including:

a first extension arm movable with respect to said first rail between a retracted position and an extended position;

a second extension arm movable with respect to said second rail between a retracted position and an extended position;

a first engagement mechanism carried at a distal end of said first extension arm and removably coupled to said first rail so as to be vertically movable with respect to said first rail;

a second engagement mechanism carried at a distal end of said second extension arm and removably coupled to said second rail so as to be movable with respect to said second rail; and

a drive mechanism arranged to move said first and second extension arms between said retracted position, in which said first and second engagement mechanisms are not captured by said first and second rails, and said extended position, in which said first and second engagement mechanisms are vertically movably captured between said first and second rails.

11. The lift frame system of claim 10 wherein:

said drive mechanism is arranged to simultaneously move both said first and second extension arms between said respective retracted and extended positions.

12. The lift frame system of claim 11 wherein said drive mechanism comprises:

an actuator;

a lead screw rotatable by said actuator; and

a carriage drivable by said lead screw, said carriage being coupled to said first extension arm for positioning thereof.

13. The lift frame system of claim 10 wherein said first engagement mechanism comprises:

a side roller rotatively mounted to a side roller carrier assembly;

a front roller rotatively mounted to a front roller carrier assembly; and

a back roller rotatively mounted to a back roller carrier assembly.

14. The lift frame system of claim 13 wherein said first engagement mechanism further comprises:

a base plate defining a planar surface, said side roller carrier assembly mounted to said base plate;

a wedge assembly coupled to said base plate so as to be movable in a perpendicular direction with respect to said planar surface, said wedge assembly having forward- and rearward-facing beveled driving surfaces with respect to said planar surface;

a rearward-facing beveled driven surface formed on said front roller carrier assembly slidingly captured at said forward-facing beveled driving surface of said wedge assembly; and

a forward-facing beveled driven surface formed on said rear roller carrier assembly slidingly captured at said rearward-facing driving beveled surface of said wedge assembly.

15. The lift frame system of claim 14 wherein said first engagement mechanism further comprises:

a table, said front and rear roller carrier assemblies slideably captured by said table.

16. The lift frame system of claim 15 wherein:

said forward- and rearward-facing beveled driving surfaces of said wedge assembly and said table each have a T-slot formed therein for slideably capturing said front and rear roller carrier assemblies.

17. The lift frame system of claim 14 wherein said first extension arm comprises:

a rod connected between said drive mechanism and said wedge assembly; and

a spring coupled between said drive mechanism and said base plate.

18. A method for stabilizing a well lift frame comprising the steps of:

coupling a stabilizer to said lift frame;

positioning said stabilizer between vertically-oriented first and second stabilization rails such that a first engagement mechanism is removably coupled to said first rail and a second engagement mechanism is removably coupled to said second rail; and

actuating a drive mechanism to move a first extension arm of said stabilizer from a retracted position, in which said first and second engagement mechanisms are not captured by said first and second rails, and an extended position, in which said first and second engagement mechanisms are movably captured between said first and second rails.

19. The method of claim 18 further comprising the step of:

actuating said drive mechanism to move a second extension arm.

20. The method of claim 19 further comprising the step of:

simultaneously moving both said first and second extension arms by said drive mechanism.

21. The method of claim 18 further comprising the step of:

moving by said drive mechanism a side roller into engagement with said first rail; and then

moving by said drive mechanism a front roller and a back roller into engagement with said first rail.