Force application reduction employing actuator

Abstract

An apparatus including a first actuator including a first housing defining a first internal region, a first head disposed in the first internal region, the first head defining first and second portions of the first internal region, and a first elongated member connected to the first head and extending out of the first housing. The apparatus further includes a first arm connected to the first elongated member to transfer to the first elongated member at least a first portion of a first force applied in a first direction by at least the weight of at least a tubular component, and a first pressurized fluid source in fluid communication with the first portion of the first internal region to apply a second force against the first head in a second direction that is opposite the first direction. According to one aspect, the tubular component is part of a quill.

What is claimed is: 
     
         1 . An apparatus, comprising:
 a first actuator, comprising:
 a first housing defining a first internal region; 
 a first head disposed in the first internal region, the first head defining on either side thereof first and second portions of the first internal region; and 
 a first elongated member connected to the first head and extending out of the first housing; 
   a first arm connected to the first elongated member to transfer to the first elongated member at least a first portion of a first force applied in a first direction by at least the weight of at least a tubular component; and   a first pressurized fluid source in fluid communication with the first portion of the first internal region to apply a second force against the first head in a second direction that is opposite the first direction.   
     
     
         2 . The apparatus of  claim 1  further comprising the tubular component. 
     
     
         3 . The apparatus of  claim 2  further comprising a top drive which comprises:
 a quill, wherein the tubular component is part of the quill; and 
 a structural member to which the first housing is connected; 
 wherein at least the quill, the first arm, the first elongated member and the first head are movable, relative to the structural member and the first housing, in the first and second directions. 
 
     
     
         4 . The apparatus of  claim 1  wherein the first actuator is a hydraulic cylinder, the first housing is a cylinder housing, the first head is a piston, and the first elongated member is a rod. 
     
     
         5 . The apparatus of  claim 1  wherein the first pressurized fluid source comprises a hydraulic accumulator to passively supply a substantially constant pressure to the first portion of the first internal region so that the second force is substantially constant and at least partially counteracts the first force. 
     
     
         6 . The apparatus of  claim 1  further comprising a second pressurized fluid source in fluid communication with the second portion of the first internal region to apply a third force against the first head in the first direction to place the first arm, relative to the first housing, at a predetermined position along a linear axis that extends in the first and second directions. 
     
     
         7 . The apparatus of  claim 6  wherein the first pressurized fluid source is a hydraulic accumulator; and
 wherein the apparatus further comprises: 
 a first control valve in fluid communication with the hydraulic accumulator to selectively supply a first fluid to the hydraulic accumulator; 
 a one-way valve to permit flow of the first fluid from the first control valve to the hydraulic accumulator and to prevent backflow of the first fluid from the hydraulic accumulator to the first control valve; and 
 a second control valve in fluid communication with, and fluidically disposed between, the second pressurized fluid source and the second portion of the first internal region to selectively supply a second fluid to the second portion of the first internal region. 
 
     
     
         8 . The apparatus of  claim 7  further comprising a controller operably coupled to at least the first and second control valves to controllably place the first arm at the predetermined position. 
     
     
         9 . The apparatus of  claim 8  further comprising a position sensor operably coupled to the first actuator to measure a linear displacement of the first arm along the linear axis;
 wherein the position sensor is operably coupled the controller to provide feedback to the controller to place or maintain the first arm at the predetermined position. 
 
     
     
         10 . The apparatus of  claim 1  wherein the first pressurized fluid source comprises a pump to actively supply a substantially constant pressure to the first portion of the first internal region so that the second force is substantially constant and at least partially counteracts the first force. 
     
     
         11 . The apparatus of  claim 10  wherein the first pressurized fluid source further comprises:
 a relieving regulator in fluid communication with, and fluidically disposed between, the pump and the first portion of the first internal region to selectively supply a first fluid to the first portion of the first internal region; and 
 a one-way valve to permit flow of the first fluid from the pump to the relieving regulator and to prevent backflow of the first fluid from the relieving regulator towards the pump. 
 
     
     
         12 . The apparatus of  claim 11  further comprising:
 a second pressurized fluid source in fluid communication with the second portion of the first internal region to apply a third force against the first head in the first direction to place the first arm, relative to the first housing, at a predetermined position along a linear axis that extends in the first and second directions; and 
 a control valve in fluid communication with, and fluidically disposed between, the second pressurized fluid source and the second portion of the first internal region to selectively supply a second fluid to the second portion of the first internal region. 
 
     
     
         13 . The apparatus of  claim 12  further comprising a controller operably coupled to at least the relieving regulator and the control valve to controllably place the first arm at the predetermined position. 
     
     
         14 . The apparatus of  claim 13  further comprising a position sensor operably coupled to the first actuator to measure a linear displacement of the first arm along the linear axis;
 wherein the position sensor is operably coupled to the controller to provide feedback to the controller to place or maintain the first arm at the predetermined position. 
 
     
     
         15 . The apparatus of  claim 1  further comprising:
 a bearing carrier connected to the first arm to rotatably support the tubular component; 
 a first slot formed through the first arm; 
 a first planar bearing element connected to the first arm; 
 a second slot formed through the first planar bearing element, wherein at least a portion of the second slot overlaps at least a portion of the first slot; and 
 a first pin extending through the first and second slots; 
 wherein the first arm and the first planar bearing element are movable, relative to the first pin, in the first and second directions. 
 
     
     
         16 . The apparatus of  claim 15  further comprising:
 a second actuator, comprising:
 a second housing defining a second internal region; 
 a second head disposed in the second internal region, the second head defining on either side thereof first and second portions of the second internal region; and 
 a second elongated member connected to the second head and extending out of the second housing; 
 
 a second arm connected to each of the bearing carrier and the second elongated member to transfer to the second elongated member at least a second portion of the first force applied in the first direction by at least the weight of at least the tubular component, wherein the bearing carrier extends between the first and second arms; 
 a third slot formed through the second arm; 
 a second planar bearing element connected to the second arm; 
 a fourth slot formed through the second planar bearing element, wherein at least a portion of the fourth slot overlaps at least a portion of the third slot; 
 a second pin extending through the third and fourth slots; and 
 a structural member to which the first and second pins, and the first and second housings, are connected; 
 wherein the first pressurized fluid source is in fluid communication with the first portion of the second internal region to apply a fourth force against the second head in the second direction; and 
 wherein the bearing carrier, the first and second arms, the first and second planar bearing elements, the first and second elongated members, and the first and second heads, are movable, relative to the structural member, the first and second housings, and the first and second pins, in the first and second directions. 
 
     
     
         17 . An apparatus, comprising:
 a coupling to engage a quill having a weight;   an arm connected to the coupling and to which a first force is applied in a first direction by at least a portion of the weight of the quill; and   an actuator connected to the arm to apply thereto a second force to at least counteract the first force.   
     
     
         18 . The apparatus of  claim 17  further comprising a bearing carrier rotatably supporting the quill, wherein the coupling is coupled to the bearing carrier. 
     
     
         19 . The apparatus of  claim 18  wherein the arm is a first arm and the actuator is a first actuator, and wherein the apparatus further comprises:
 a second arm connected to the coupling and to which a third force is applied in the first direction by at least a portion of the weight of the quill, wherein the coupling and the bearing carrier extend between the first and second arms; and 
 a second actuator connected to the second arm to apply to the second arm a fourth force to at least counteract the first and third forces when in combination with the second force. 
 
     
     
         20 . The apparatus of  claim 19  further comprising:
 first and second slots formed through the first and second arms, respectively; 
 first and second planar bearing elements connected to the first and second arms, respectively; 
 third and fourth slots formed through the first and second planar bearing elements, respectively, wherein at least portions of the third and fourth slots overlap at least portions of the first and second slots, respectively; and 
 first and second pins extending through the first and third slots, and the second and fourth slots, respectively; 
 wherein at least the coupling, the bearing carrier, the first and second arms, and the first and second planar bearing elements are movable, relative to the first and second pins, in the first direction and a second direction opposite thereto. 
 
     
     
         21 . The apparatus of  claim 19  further comprising the quill, wherein the quill is engaged with the coupling and is rotatably supported by the bearing carrier. 
     
     
         22 . The apparatus of  claim 21  further comprising;
 a top drive, comprising:
 the quill; and 
 a structural member to which the first and second actuators are connected; 
 
 wherein at least the quill, the coupling, the bearing carrier, and the first and second arms are movable, relative to the structural member, in the first direction and a second direction opposite thereto. 
 
     
     
         23 . A method, comprising:
 suspending a tubular component and a structural member;   permitting the tubular component to move, relative to the structural member, in a first direction while continuing to suspend the tubular component and the structural member; and   reducing a first force applied in the first direction against a tubular member in response to permitting the tubular component to move in the first direction, comprising:
 applying a second force against the tubular component in a second direction that is opposite the first direction. 
   
     
     
         24 . The method of  claim 23  wherein the first force applied in the first direction against the tubular member is due, at least in part, to the weight of the tubular component and the ability of the tubular component to move relative to the structural member. 
     
     
         25 . The method of  claim 24  wherein the tubular component is part of a quill of a top drive; and
 wherein the tubular member is, or is to be, part of a string of drill pipe or casing. 
 
     
     
         26 . The method of  claim 24  wherein applying the second force against the tubular component in the second direction comprises passively supplying a substantially constant pressure to a first internal region, through which an elongated member extends, the elongated member being connected to the tubular component. 
     
     
         27 . The method of  claim 26  further comprising applying a third force in the first direction against a head connected to the elongated member to place the tubular component, relative to the structural member, at a predetermined position along a linear axis that extends in the first and second directions. 
     
     
         28 . The method of  claim 27  further comprising:
 employing a position sensor to measure the linear displacement of the tubular component, relative to the structural member, along the linear axis; and 
 providing feedback to a controller operably coupled to the position sensor to controllably place or maintain the tubular component at the predetermined position. 
 
     
     
         29 . The method of  claim 24  wherein applying the second force against the tubular component in the second direction comprises actively supplying a substantially constant pressure to a first internal region, through which an elongated member extends, the elongated member being connected to the tubular component. 
     
     
         30 . The method of  claim 29  further comprising applying a third force in the first direction against a head connected to the elongated member to place the tubular component, relative to the structural member, at a predetermined position along a linear axis that extends in the first and second directions. 
     
     
         31 . The method of claim of  claim 30  further comprising:
 employing a position sensor to measure the linear displacement of the tubular component, relative to the structural member, along the linear axis; and 
 providing feedback to a controller operably coupled to the position sensor to controllably place or maintain the tubular component at the predetermined position. 
 
     
     
         32 . The method of  claim 24  further comprising:
 rotatably supporting the tubular component; and 
 guiding an arm connected to the tubular component during movement of the tubular component, relative to the structural member, in the first or second direction.