Light-weight single joint manipulator arm

Abstract

The present invention provides an apparatus and a method for making up tubular strings in a well. The present invention provides a single joint manipulator arm for manipulating and positioning tubing joints for coupling into a tubular string. In one embodiment, a string elevator is supported by a hoist. A single joint elevator is supported on a swing arm that is pivotally secured to the sub-hoist assembly. An actuator rotates the swing arm to an initial position for securing to an add-on tubular joint whereby the single joint elevator engages a proximate end of the add-on tubular joint. As the hoist is lifted, a damper dampens rotation of the swing arm as it finds gravitational equilibrium with the single joint held in a substantially vertical orientation. A distal end of the tubular joint is aligned with a casing string supported by a spider, and the tubular joint is threadably coupled to the tubular string. The actuator may include provisions to power the arm from the vertical orientation to a substantially horizontal orientation and also to dampen the movement of the arm as it moves from the substantially horizontal or an intermediate position to the vertical orientation once the single joint elevator engages the add-on tubular joint and the hoist suspends the joint for rotation.

1 . An apparatus, for manipulating tubular segments for being made up into a tubular string, the apparatus comprising:
 a swing arm having a proximal end pivotally coupled to a hoist at a location above a string elevator or a casing running tool;   an actuator pivotally secured to the swing arm for rotating the swing arm;   a damper pivotally secured to the swing arm, for damping rotation of the swing arm; and   a single joint elevator secured to a distal end of the swing arm for releasably supporting a tubular segment, the swing arm being rotatable to align the tubular segment with another tubular segment to form a tubular string.   
   
   
       2 . The apparatus of  claim 1 , wherein the actuator is a hydraulic or a pneumatic cylinder. 
   
   
       3 . The apparatus of  claim 2 , wherein the cylinder also functions as the damping member. 
   
   
       4 . The apparatus of  claim 1 , wherein the damper comprises a hydraulic or a pneumatic cylinder. 
   
   
       5 . The apparatus of  claim 1 , wherein the single joint elevator comprises a horseshoe elevator or a hinged-body elevator. 
   
   
       6 . The apparatus of  claim 1 , further comprising:
 a sacrificially failing link coupled between the single joint elevator and the swing arm, the single joint elevator being pivotable about the distal end of the swing arm between a first position with the sacrificially failing link intact and a second position assumed upon failure of the sacrificially failing link.   
   
   
       7 . The apparatus of  claim 6 , further comprising:
 a safety link pivotally secured to the swing arm with the sacrificially failing link coupled to the safety link and also to the swing arm such that the safety link supports the single joint elevator upon failure of the sacrificially failing link.   
   
   
       8 . A method of making up a tubing string for installation in a borehole comprising:
 suspending a string elevator on bails;   supporting a single joint elevator on a pivot arm pivotally secured to the bails at a location above the string elevator;   rotating the swing arm to a first position wherein an axis of the single joint elevator is substantially angularly misaligned from an axis of the string elevator;   engaging a proximate end of a tubing segment with the single joint elevator; and   rotating the swing arm to substantially align a distal end of the tubing segment with a tubing string positioned in the well, while damping the rotation of the swing arm.   
   
   
       9 . The method of  claim 8 , wherein damping the movement of the swing arm results from moving a piston within a cylinder. 
   
   
       10 . The method of  claim 9 , further comprising moving the swing arm to the luffing position by energizing the cylinder. 
   
   
       11 . The method of  claim 10 , wherein the luffing position is substantially horizontal. 
   
   
       12 . The method of  claim 8 , further comprising one or both of raising and lowering the string elevator and the single joint elevator using a hoist. 
   
   
       13 . The method of  claim 8 , further comprising:
 lowering the hoist to position the distal end of the tubing segment adjacent a proximate end of the tubing string; and   threadedly coupling the distal end of the tubing segment with the proximate end of the tubing string.   
   
   
       14 . The method of  claim 13 , further comprising:
 Rotating the swing arm to remove it from obstructing descent of the string elevator;   lowering the hoist to position the string elevator about the proximate end of the tubing joint connected with the tubing string;   engaging the proximate end of the tubing segment with the string elevator;   raising the hoist and string elevator to at least partially unweight a spider supporting the tubing string;   disengaging the spider from the tubing string;   lowering the hoist to install the tubing string further into the well; and   re-engaging the tubing string with the spider to support the tubing string in a the well.   
   
   
       15 . An apparatus for making up and installing a tubular string is a well comprising:
 a vertically movable top drive;   a sub supported by the top drive and pivotably supporting a swing arm coupled to the sub at its proximal end and coupled to a single joint elevator at its distal end;   an actuator for rotating the swing arm about its pivoting coupling to the sub between a luffing position and an aligned position with the well; and   a damper for opposing swing rotation of the swing arm from the luffing position to the aligned position.   
   
   
       16 . The apparatus of  claim 15  wherein the actuator is a hydraulic or pneumatic cylinder. 
   
   
       17 . The apparatus of  claim 16  wherein the cylinder also functions as the damper. 
   
   
       18 . An apparatus for manipulating tubular segments for being made up into a tubular string and run into a well comprising:
 a swing arm for pivotably coupling at its proximal end to a sub or bail above a string elevator or casing running tool, the swing arm having a distal end coupled to a single joint elevator;   an actuator for powered rotation of the swing arm between a removed position; and a damper for slowing the rotation of the swing arm from the removed position to the aligned position.   
   
   
       19 . The apparatus of  claim 18  wherein the actuator is a pneumatic or hydraulic cylinder. 
   
   
       20 . The apparatus of  claim 19  wherein the cylinder also functions as the damper.