Pipe injectors and methods of introducing tubing into or removing it from a well bore

Abstract

A pipe injector assembly is disclosed, comprising: a pipe injector that includes at least three tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are laterally displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the lateral spacing between the drive components is increased to permit the passage of a coupling of the tubing. A pipe injector assembly is also disclosed, comprising: a pipe injector that includes at least two tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the spacing between the drive components is increased to permit the passage of a coupling of the tubing; and a set of tubing slips that are laterally displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the lateral spacing between the tubing slips is increased to permit the passage of the coupling; in which the pipe injector is displaceable longitudinally relative to the set of tubing slips.

1 . A pipe injector assembly, comprising:
 a pipe injector that includes at least three tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are laterally displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the lateral spacing between the drive components is increased to permit the passage of a coupling of the tubing.   
   
   
       2 . The pipe injector assembly of  claim 1  in which the tubing drive units comprise endless chain tubing drive units. 
   
   
       3 . The pipe injector assembly of  claim 2  in which the drive components associated with each endless chain tubing drive unit comprise:
 a chain guide;   an endless feed chain supported on the chain guide and configured in the closed condition to drivingly engage said tubing; and   a chain drive arrangement.   
   
   
       4 . The pipe injector assembly of  claim 1  in which the tubing drive units are arranged equiangularly around the feed axis. 
   
   
       5 . The pipe injector assembly of  claim 1  in which the pipe injector is displaceable longitudinally relative to the feed axis when in the open condition. 
   
   
       6 . The pipe injector assembly of  claim 1  in which the pipe injector is displaceable longitudinally relative to a set of tubing slips that are displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the spacing between the tubing slips is increased to permit the passage of the coupling. 
   
   
       7 . The pipe injector assembly of  claim 1  further comprising a second injector positioned below and in register with the pipe injector along the feed axis. 
   
   
       8 . The pipe injector assembly of  claim 7  in which the second pipe injector comprises at least two tubing drive units radially arranged around the feed axis, the tubing drive units of the second pipe injector including drive components that are displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the spacing between the drive components is increased to permit the passage of the coupling;
 in which the tubing drive units of the pipe injector are displaceable from the closed condition to the open condition independently of the tubing drive units of the second pipe injector.   
   
   
       9 . The pipe injector assembly of  claim 8  in which the second pipe injector comprises at least three tubing drive units radially arranged around the feed axis. 
   
   
       10 . The pipe injector assembly of  claim 8  in which the tubing drive units of the second pipe injector comprise endless chain tubing drive units. 
   
   
       11 . The pipe injector assembly of  claim 1  further comprising a sensor configured to sense the presence of a coupling connecting. 
   
   
       12 . A method of introducing tubing into or removing it from a well bore, the method comprising:
 displacing tubing into or out of a well bore by a pipe injector having at least three tubing drive units radially arranged around the tubing, the tubing drive units having drive components which drivingly engage the tubing;   displacing at least some of the drive components of the tubing drive units outwardly to permit a coupling in the tubing to pass between the drive components; and   once the coupling has passed the drive units, displacing the drive components inwardly to drivingly engage the tubing.   
   
   
       13 . The method of  claim 12  further comprising:
 when the drive components of the pipe injector are displaced outwardly, displacing the pipe injector longitudinally in a direction opposite to a feed direction of the tubing; and   once the drive components have passed the coupling, displacing the drive components inwardly to drivingly engage the tubing.   
   
   
       14 . The method of  claim 12  in which a second pipe injector is positioned below and in register with the pipe injector along the feed axis, the second pipe injector having at least two tubing drive units including drive components that drivingly engage the tubing, the drive components being radially arranged around the tubing, the method further comprising:
   1 displacing drive components of the pipe injector outwardly and displacing the tubing longitudinally using the second pipe injector to permit a coupling in the tubing to pass the pipe injector; and   displacing drive components of the second pipe injector outwardly and displacing the tubing longitudinally using the pipe injector to permit a coupling in the tubing to pass the second pipe injector.   
   
   
       15 . A pipe injector assembly, comprising:
 a pipe injector that includes at least two tubing drive units radially arranged around a feed axis along which tubing is fed, the tubing drive units having drive components that are displaceable between a closed condition in which the drive components drivingly engage said tubing and an open condition in which the spacing between the drive components is increased to permit the passage of a coupling of the tubing; and   a set of tubing slips that are laterally displaceable between a closed condition in which the tubing slips grip the tubing and an open condition in which the lateral spacing between the tubing slips is increased to permit the passage of the coupling;   in which the pipe injector is displaceable longitudinally relative to the set of tubing slips.   
   
   
       16 . The pipe injector assembly of  claim 15  further comprising a jacking arrangement between the set of tubing slips and the pipe injector. 
   
   
       17 . The pipe injector assembly of  claim 16  in which the jacking arrangement comprises a hydraulic piston and cylinder arrangement. 
   
   
       18 . A method of introducing tubing into or removing it from a well bore, the method comprising:
 providing a set of tubing slips and a pipe injector having at least two tubing drive units radially arranged around the tubing, the tubing drive units having drive components which drivingly engage the tubing;   displacing the set of tubing slips outwardly and displacing the tubing longitudinally using the pipe injector to permit a coupling in the tubing to pass the set of tubing slips; and   displacing the drive components outwardly and gripping the tubing longitudinally using the set of tubing slips to longitudinally displace the drive components relative to the set of tubing slips to permit a coupling in the tubing to pass the drive components.   
   
   
       19 . The method of  claim 18  in which gripping further comprises gripping the tubing using the set of tubing slips and longitudinally displacing the drive components relative to the set of tubing slips using a jacking arrangement between the tubing drive units and the set of tubing slips. 
   
   
       20 . The method of  claim 18  in which the drive components are displaced longitudinally relative to a tubing feed direction.