Method and system for predicting sand failure in a hydrocarbon production well and method and system for producing hydrocarbon fluids from an earth formation

Abstract

Bottom hole pressure (BHP) actuals and bottom hole temperature (BHT) actuals in a hydrocarbon production well are recorded as a function of time, during production of hydrocarbon fluids. Selective statistical measures of both the BHP actuals and the BHT actuals are determined as a function of time. These selective statistical measures suitably represent estimates of expected normal BHP actuals and BHT actuals in case there is no imminent sand failure, supplemented with an uncertainty measure of the estimates of expected normal BHP and BHT. The BHP actuals and the BHT actuals are compared with respective BHP and BHT anomaly thresholds based on the selective statistical measures. An anomaly alert is automatically issued upon meeting a condition wherein both the BHP actuals and the BHT actuals exceed their respective anomaly threshold. The anomaly alert is an indication of a predicted imminent sand failure of the hydrocarbon production well in operation.

1 . A computer-implemented method of predicting sand failure of a hydrocarbon production well in operation, comprising:
 recording bottom hole pressure (BHP) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids;   recording bottom hole temperature (BHT) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids;   determining selective statistical measures of both the BHP actuals and the BHT actuals as a function of time;   defining a BHP anomaly threshold and a BHT anomaly threshold over time, based on the selective statistical measures;   comparing the BHP actuals and the BHT actuals with the respective anomaly thresholds; and   automatically issuing an anomaly alert upon meeting a condition wherein both the BHP actuals and the BHT actuals exceed their respective anomaly threshold.   
     
     
         2 . The computer-implemented method of  claim 1 , further comprising a predetermined alert delay time, wherein the condition comprises that both the BHP actuals and the BHT actuals exceed their respective anomaly threshold for a duration of at least the alert delay time. 
     
     
         3 . The computer-implemented method of  claim 1 , wherein recording of said BHP actuals comprise sensing a BHP with a pressure sensor configured within the hydrocarbon production well; and wherein recording of said BHT actuals comprise sensing a BHT with a temperature sensor configured within the hydrocarbon production well. 
     
     
         4 . The computer-implemented method of  claim 1 , wherein the hydrocarbon production well comprises completion equipped with a sand control device. 
     
     
         5 . The computer-implemented method of  claim 4 , wherein the sand control device comprises one or both of a sand screen and a gravel pack. 
     
     
         6 . The computer-implemented method of  claim 1 , wherein said selective statistical measures represent estimates of expected normal BHP actuals and BHT actuals in case there is no imminent sand failure, and an uncertainty measure of the estimates. 
     
     
         7 . The computer-implemented method of  claim 6 , wherein said selective statistical measures are determined based on BHP actuals within a predetermined first rolling time window and on BHT actuals within a predetermined second rolling time window. 
     
     
         8 . The computer-implemented method of  claim 7 , wherein each uncertainty measure corresponds to a standard deviation of an average; and wherein determining said selective statistical measures comprises:
 determining a BHP rolling average of the BHP actuals, and a BHP rolling standard deviation, both as a function of time, and both based on the BHP actuals in the predetermined first rolling time window;   determining a BHT rolling average of the BHT actuals, and a BHT rolling standard deviation, both as a function of time, and both based on the BHT actuals in the predetermined second rolling time window;   
       and wherein said BHP anomaly threshold over time is based on the BHP rolling average and the BHP rolling standard deviation and said BHT anomaly threshold over time is based on the BHT rolling average and the BHT rolling standard deviation. 
     
     
         9 . The computer-implemented method of  claim 8 , further comprising a predetermined BHP control limit factor which determines how many times the BHP rolling standard deviation the BHP anomaly threshold is removed from the BHP rolling average and at each time and/or further comprising a predetermined BHT control limit factor which determines how many times the BHT rolling standard deviation the BHT anomaly threshold is removed from the BHT rolling average and at each time. 
     
     
         10 . The computer-implemented method of  claim 1 , wherein adjusting a hydrocarbon production parameter, upon an anomaly alert being issued, in order to mitigate production of sand. 
     
     
         11 . A computerized system for predicting sand failure of a hydrocarbon production well in operation, comprising:
 a memory for recording bottom hole pressure (BHP) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids, for recording bottom hole temperature (BHT) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids;   a processing unit configured to execute computer readable instructions for:   determining selective statistical measures of both the BHP actuals and the BHT actuals as a function of time;   defining a BHP anomaly threshold and a BHT anomaly threshold over time, based on the selective statistical measures;   comparing the BHP actuals and the BHT actuals with the respective anomaly thresholds; and   automatically issuing an anomaly alert upon meeting a condition wherein both the BHP actuals and the BHT actuals exceed their respective anomaly threshold; and   an output device for outputting said anomaly alert.   
     
     
         12 . The computerized system of  claim 11 , further comprising an input interface connectable to a pressure sensor configured within the hydrocarbon production well and to a temperature sensor configured within the hydrocarbon production well whereby signals representing BHP actuals and BHT actuals pass through the interface to the memory. 
     
     
         13 . The computerized system of  claim 11 , wherein said determining of selective statistical measures of both the BHP actuals and the BHT actuals as a function of time comprises:
 determining a BHP rolling average of the BHP actuals, and a BHP rolling standard deviation, both as a function of time, and both based on the BHP actuals within a predetermined first rolling time window;   determining a BHT rolling average of the BHT actuals, and a BHT rolling standard deviation, both as a function of time, and both based on the BHT actuals within a predetermined second rolling time window;   
       and wherein said BHP anomaly threshold over time is based on the BHP rolling average and the BHP rolling standard deviation and said BHT anomaly threshold over time is based on the BHT rolling average and the BHT rolling standard deviation. 
     
     
         14 . A method of producing hydrocarbon fluids from an Earth formation with a hydrocarbon production well, comprising:
 allowing hydrocarbon fluid from the Earth formation to flow into the hydrocarbon production well in a bottom hole location;   recording bottom hole pressure (BHP) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids;   recording bottom hole temperature (BHT) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids;   determining selective statistical measures of both the BHP actuals and the BHT actuals as a function of time;   defining a BHP anomaly threshold and a BHT anomaly threshold over time, based on the selective statistical measures;   comparing the BHP actuals and the BHT actuals with the respective anomaly thresholds; and   automatically issuing an anomaly alert upon meeting a condition wherein both the BHP actuals and the BHT actuals exceed their respective anomaly threshold.   
     
     
         15 . The method of  claim 14 , further comprising a predetermined alert delay time, wherein the condition comprises that both the BHP actuals and the BHT actuals exceed their respective anomaly threshold for a duration of at least the alert delay time. 
     
     
         16 . The method of  claim 14 , wherein recording of said BHP actuals comprise sensing a BHP with a pressure sensor configured within the hydrocarbon production well; and
 wherein recording of said BHT actuals comprise sensing a BHT with a temperature sensor configured within the hydrocarbon production well.   
     
     
         17 . The method of  claim 14 , wherein said selective statistical measures represent estimates of expected normal BHP actuals and BHT actuals, both in case there is no imminent sand failure, and an uncertainty measure of the estimates. 
     
     
         18 . The method of  claim 14 , wherein said determining of selective statistical measures of both the BHP actuals and the BHT actuals as a function of time comprises:
 determining a BHP rolling average of the BHP actuals, and a BHP rolling standard deviation, both as a function of time, and both based on the BHP actuals in a predetermined first rolling time window;   determining a BHT rolling average of the BHT actuals, and a BHT rolling standard deviation, both as a function of time, and both based on the BHT actuals in a predetermined second rolling time window;   
       and wherein said BHP anomaly threshold over time is based on the BHP rolling average and the BHP rolling standard deviation and said BHT anomaly threshold over time is based on the BHT rolling average and the BHT rolling standard deviation. 
     
     
         19 . The method of  claim 14 , wherein adjusting a hydrocarbon production parameter, upon an anomaly alert being issued, in order to mitigate production of sand. 
     
     
         20 . A system for producing hydrocarbon fluids from an Earth formation, comprising:
 a hydrocarbon production well penetrating into a hydrocarbon fluid containing region of an Earth formation; and   a computerized system for predicting sand failure of the hydrocarbon production well in operation, wherein said computerized system comprises:
 a memory for recording bottom hole pressure (BHP) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids, for recording bottom hole temperature (BHT) actuals in a hydrocarbon production well as a function of time, during production of hydrocarbon fluids; 
 a processing unit configured to execute computer readable instructions for: 
   determining selective statistical measures of both the BHP actuals and the BHT actuals as a function of time;   defining a BHP anomaly threshold and a BHT anomaly threshold over time, based on the selective statistical measures;   comparing the BHP actuals and the BHT actuals with the respective anomaly thresholds; and   automatically issuing an anomaly alert upon meeting a condition wherein both the BHP actuals and the BHT actuals exceed their respective anomaly threshold; and
 an output device for outputting said anomaly alert.