Method And System For Controlling A Well Service Rig Based On Load Data

Abstract

The present invention is directed to methods for controlling the operations of a well service rig at a well site by evaluating load sensor data obtained from sensors on or associated with the well service rig. A rig load data chart can be reviewed and an average rig load can be determined for each pull of tubing or rods from a well. The average rig load can be used to calculate and set a rig overload level. If the rig load sensor reads a rig load at or above the rig overload level, the clutch for the hoist can be disengaged and the brake applied to prevent the load from either damaging the rig or breaking off the tubing or rods in the well. In addition, the rig load can be evaluated to determine when the limit the block speed when pulling rods or tubing.

1 - 10 . (canceled) 
     
     
         11 . A method for limiting block speed while pulling pipe from a well comprising the steps of:
 receiving load data comprising the load of a pipe string being removed from a well;   computing an average load based on the load data;   determining if the average load is below a predetermined level; and   limiting block speed below a predetermined speed based on a positive determination that the average load is below a predetermined level.   
     
     
         12 . The method of  claim 11 , wherein computing the average load based on the load data comprises the steps of:
 determining a start time for pulling a stand of the pipe from the well;   determining a completion time for pulling the stand of the pipe from the well;   removing a predetermined amount of the load data between the start time and the completion time; and   computing the average load of the well service rig.   
     
     
         13 . The method of  claim 12 , further comprising the steps of:
 receiving a weight for the well service rig; and   computing a hookload by calculating the difference between the average load and the weight of the well service rig.   
     
     
         14 . The method of  claim 12 , wherein computing the average load comprises calculating an average of the remaining load data that was not removed between the start time and the completion time. 
     
     
         15 . The method of  claim 12 , wherein removing a predetermined amount of the load data between the start time and the completion time further comprises:
 removing a first predetermined amount of the load data for a first predetermined amount of time beginning at the start time; and   removing a second predetermined amount of the load data for a second predetermined amount of time concluding at the completion time.   
     
     
         16 . The method of  claim 15 , wherein the first and second predetermined amounts of time are a predetermined percentage of a difference between the completion time and the start time. 
     
     
         17 - 25 . (canceled) 
     
     
         26 . The method of  claim 11 , wherein the load data is received from at least one load sensor on a well service rig. 
     
     
         27 . The method of  claim 11 , wherein the predetermined speed is three feet per second. 
     
     
         28 . The method of  claim 11 , wherein the predetermined load level is between five and fifteen thousand pounds of hookload. 
     
     
         29 . The method of  claim 11 , further comprising the step of increasing slippage in a transmission for a hoist, wherein the speed of the hoist controls the block speed. 
     
     
         30 . The method of  claim 11 , further comprising the step of reducing air pressure to a hoist clutch bladder. 
     
     
         31 . A method for limiting block speed while pulling pipe from a well comprising the steps of:
 receiving load data comprising the load of a pipe string being removed from a well;   computing an average load based on the load data comprising the steps of:
 removing a predetermined amount of the load data between a start time and a completion time; and 
 computing the average load of a well service rig determining if the average load is below a predetermined level; and 
   limiting block speed below a predetermined speed based on a positive determination that the average load is below a predetermined level.   
     
     
         32 . The method of  claim 31 , further comprising the steps of:
 receiving a weight for the well service rig; and   computing a hookload by calculating the difference between the average load and the weight of the well service rig.   
     
     
         33 . The method of  claim 31 , wherein computing the average load comprises calculating an average of the remaining load data that was not removed between the start time and the completion time. 
     
     
         34 . The method of  claim 31 , wherein removing a predetermined amount of the load data between the start time and the completion time further comprises:
 removing a first predetermined amount of the load data for a first predetermined amount of time beginning at the start time; and   removing a second predetermined amount of the load data for a second predetermined amount of time concluding at the completion time.   
     
     
         35 . The method of  claim 34 , wherein the first and second predetermined amounts of time are a predetermined percentage of a difference between the completion time and the start time. 
     
     
         36 . The method of  claim 31 , wherein the load data is received from at least one load sensor on a well service rig. 
     
     
         37 . The method of  claim 31 , wherein the predetermined load level is between five and fifteen thousand pounds of hookload. 
     
     
         38 . The method of  claim 31 , further comprising the step of increasing slippage in a transmission for a hoist, wherein the speed of the hoist controls the block speed. 
     
     
         39 . The method of  claim 31 , further comprising the step of reducing air pressure to a hoist clutch bladder.