Positive engagement indicator for remotely operated well pressure control apparatus

Abstract

A wellhead pressure control fitting includes a plurality of locks to engage a mating surface of an adapter sealingly seated in a receptacle. The locks each comprise a sensor arranged to measure an amount of movement or rotation of each lock so that full closure of each lock against the adapter is determinable.

What is claimed is: 
     
         1 . A wellhead pressure control fitting, comprising:
 a generally tubular Pressure Control Equipment (PCE) adapter assembly;   the generally tubular pressure control assembly configured to mate with a wellhead and having a plurality of cam locks, each cam lock configured to rotate;   means for rotating the cam locks so as to urge the adapter into a receptacle in the pressure control assembly to form a pressure tight seal between the adapter and the assembly; and   a sensor associated with each cam lock, the sensor arranged to measure a parameter related to an amount of rotation of each cam lock.   
     
     
         2 . The fitting of  claim 1  wherein the sensor associated with each cam lock comprises a rotary encoder disposed on a cam lock pin. 
     
     
         3 . The fitting of  claim 1  wherein the sensor associated with each cam lock comprises a proximity sensor arranged to measured extension of each cam lock piston. 
     
     
         4 . The fitting of  claim 1  wherein the sensor associated with each cam lock comprises an accelerometer arranged to measure a rotational orientation of each cam lock. 
     
     
         5 . The fitting of  claim 1  wherein the sensor associated with each cam lock comprises a limit switch arranged to electrically close or open only when the associated cam lock is fully rotated to a locked position. 
     
     
         6 . The fitting of  claim 1  wherein the sensor associated with each cam lock comprises a strain gauge. 
     
     
         7 . The fitting of  claim 1  wherein the sensor associated with each cam lock comprises an optical sensor. 
     
     
         8 . The fitting of  claim 1  further comprising a locking ring comprising means to extend and retract the locking ring, wherein retraction of the locking ring causes the locking ring to move so as to restrain the cam locks from rotation, and further comprising a locking ring sensor operatively engaged to the locking ring whereby measurements made by the locking ring sensor correspond to full engagement of the locking ring with the cam locks. 
     
     
         9 . The fitting of  claim 8  wherein the sensor associated with the locking ring comprises a proximity sensor arranged to measure a parameter related to extension of the locking. ring 
     
     
         10 . The fitting of  claim 8  wherein the sensor associated with the locking ring comprises a proximity sensor. 
     
     
         11 . The fitting of  claim 8  wherein the sensor associated with the locking ring comprises a limit switch arranged to electrically close or open only when the locking ring is fully engaged with the cam locks. 
     
     
         12 . The fitting of  claim 8  wherein the sensor associated with the locking ring comprises a strain gauge. 
     
     
         13 . The fitting of  claim 8  wherein the sensor associated with the locking ring comprises an optical sensor. 
     
     
         14 . A wellhead pressure control fitting, comprising:
 a generally tubular Pressure Control Equipment (PCE) configured to mate with a pressure control assembly, the pressure control assembly configured to mate with a wellhead, the adapter further providing a lower wedge assembly, the lower wedge assembly including a plurality of lower wedges, each lower wedge having first and second opposing lower wedge sides, each first lower wedge side providing protruding top and bottom lower wedge ribs; a generally hollow lower wedge receptacle, the lower wedge receptacle further providing a plurality of shaped lower wedge receptacle recesses formed in an interior thereof wherein axial displacement of the lower wedge receptacle relative to the lower wedges causes corresponding radial displacement of the lower wedges; and   a sensor arranged to measure a parameter related to an amount of engagement of the wedges with the wedge receptacle.   
     
     
         15 . The fitting of  claim 14  wherein the sensor comprises a proximity switch. 
     
     
         16 . The fitting of  claim 14  wherein the sensor comprises a limit switch. 
     
     
         17 . The fitting of  claim 14  wherein the sensor comprises a linear variable differential transformer. 
     
     
         18 . The fitting of  claim 14  wherein the sensor comprises an acoustic range finder. 
     
     
         19 . A wellhead pressure control fitting, comprising:
 a generally tubular Pressure Control Equipment (PCE) adapter having first and second adapter ends, the first adapter end configured to mate with pressure control equipment, the adapter providing an annular adapter rib distal from the first adapter end towards the second adapter end;   a generally tubular pressure control assembly having first and second assembly ends and a longitudinal centerline, the centerline defining axial displacement parallel to the centerline and radial displacement perpendicular to the centerline, the first assembly end providing a first assembly end interior, the second assembly end configured to mate with a wellhead;   the first assembly end interior providing a PCE receptacle for receiving the second adapter end, the second adapter end and the PCE receptacle further each providing cooperating abutment surfaces, the cooperating abutment surfaces forming a pressure seal between the second adapter end and the PCE receptacle when the second adapter end is received into the PCE receptacle; the first assembly end interior further providing a wedge assembly, the wedge assembly including:   a plurality of wedges, each wedge having first and second opposing wedge sides, each first wedge side providing protruding top and bottom wedge ribs;   a generally hollow wedge receptacle, the wedge receptacle further providing a plurality of shaped wedge receptacle recesses formed in an interior thereof, one wedge receptacle recess for each wedge, the wedge receptacle further having first and second opposing wedge receptacle sides in which the wedge receptacle recesses define the first wedge receptacle side; and   wherein each wedge is received into a corresponding wedge receptacle recess so that the first wedge receptacle side and the second wedge sides provide opposing sloped wedge surfaces, wherein axial displacement of the upper receptacle relative to the wedges causes corresponding radial displacement of the wedges; and wherein, as the second adapter end enters the PCE receptacle and engages the cooperating abutment surfaces, axial displacement of the wedge receptacle relative to the wedges causes corresponding radial constriction of the top and bottom wedge ribs around the adapter rib, which in turn restrains the adapter from axial displacement relative to the PCE receptacle; and   a sensor arranged to measure a parameter related to an amount of engagement of the wedges with the wedge receptacle.   
     
     
         20 . The fitting of  claim 19  wherein the sensor comprises a proximity switch. 
     
     
         21 . The fitting of  claim 19  wherein the sensor comprises a limit switch. 
     
     
         22 . The fitting of  claim 19  wherein the sensor comprises a linear variable differential transformer. 
     
     
         23 . The fitting of  claim 19  wherein the sensor comprises an acoustic range finder. 
     
     
         24 . A wellhead pressure control fitting, comprising:
 a generally tubular Pressure Control Equipment (PCE) adapter configured to mate with a pressure control assembly, the pressure control assembly configured to mate with a wellhead, the assembly providing a plurality of locking elements each disposed to lock the PCE adapter within the assembly;   a locking ring having a plurality of locking ring actuators extensible to urge the locking ring to an unlocked position wherein the plurality of locking elements are disenagageable from the PCE adapter and a locked position wherein the locking elements retain the PCE adapter within the assembly; and   at least one sensor associated the locking ring, the at least one sensor arranged to communicate a signal when the locking ring is in the locked position.   
     
     
         25 . The fitting of  claim 23  wherein the at least one sensor comprises a plurality of switches each disposed adjacent to a guide pin such that full longitudinal retraction of the locking ring closes all the plurality of switches.