Method and system for differential drilling mud measurement and alarms

Abstract

Methods, systems, and techniques for differential drilling mud measurement and for generating related alarms. A drilling mud measurement is performed during a drilling operation. The drilling mud measurement is of a volume of at least some of the drilling mud used for the drilling operation, such as total mud or trip mud. The drilling mud measurement is determined to be within an absolute mud value range, and consequently no alarm is generated in respect of the absolute mud value range. A differential is determined between the drilling mud measurement and a reference drilling mud value, and this differential is determined to exceed a differential alarm threshold. An alarm is generated in response. An alarm is accordingly generated in response to differential mud volume measurements even when not necessarily warranted based on absolute mud volume measurements, which promotes safety in the context of potential loss or influx events.

1 . A method for differential drilling mud measurement, the method comprising:
 (a) performing a drilling mud measurement during a drilling operation, wherein the drilling mud measurement is of a volume of at least some of the drilling mud used for the drilling operation;   (b) determining that the drilling mud measurement is within an absolute mud value range;   (c) determining that a differential between the drilling mud measurement and a reference drilling mud value exceeds a differential alarm threshold; and   (d) generating an alarm in response to the differential between the drilling mud measurement and the reference drilling mud value exceeding the differential alarm threshold.   
     
     
         2 . The method of  claim 1 , further comprising displaying, on a display at a drilling site at which the drilling operation is occurring, traces respectively showing a history of drilling mud measurements and corresponding absolute mud value ranges. 
     
     
         3 . The method of  claim 1 , wherein the drilling mud measurement is of total mud volume for the drilling operation, and wherein the total mud volume excludes trip mud used for tripping operations. 
     
     
         4 . The method of  claim 1 , wherein the drilling mud measurement is of trip mud used for tripping operations and excludes drilling mud used for other drilling operations. 
     
     
         5 . The method of  claim 1 , wherein the differential alarm threshold is approximately 7 m 3  of drilling mud. 
     
     
         6 . The method of  claim 1 , further comprising, prior to determining that the drilling mud measurement is within the absolute mud value range and to determining that the differential between the drilling mud measurement and the reference drilling mud value exceeds the differential alarm threshold, receiving user input explicitly requesting absolute mud value monitoring,
 wherein determining that the drilling mud measurement is within the absolute mud value range is performed in response to receiving the user input,   and wherein determining that the differential between the drilling mud measurement and the reference drilling mud value exceeds the differential alarm threshold is performed automatically in response to the user input.   
     
     
         7 . The method of  claim 1 , further comprising suspending drilling in response to the alarm. 
     
     
         8 . The method of  claim 1 , further comprising resetting the reference drilling mud value in response to a user action indicative of user attention. 
     
     
         9 . The method of  claim 8 , wherein the user action comprises at least one of acknowledging the alarm, zeroing trip mud or total mud gain/loss, setting the reference drilling mud value to a current measured pit volume, or changing the absolute mud value range. 
     
     
         10 . The method of  claim 8 , wherein determining the differential is performed while alarm generation has been disabled by a user, wherein the method further comprises receiving user input enabling the alarm generation while the alarm generation is disabled, and wherein generating the alarm is performed after receiving the user input enabling the alarm generation and is based on the differential determined while the alarm generation was disabled. 
     
     
         11 . A system for differential drilling mud measurement, the system comprising:
 (a) a mud tank;   (b) a mud pump fluidly coupled to the mud tank for pumping drilling fluid from the mud tank into a well;   (c) a volume meter affixed to the mud tank for measuring pit volume of the drilling fluid stored in the mud tank;   (d) a display;   (e) at least one processor communicatively coupled to the display, the mud pump, and the volume meter; and   (f) at least one memory communicatively coupled to the at least one processor and having stored thereon computer program code that is executable by the at least one processor and that, when executed by the at least one processor, causes the at least one processor to:
 (i) perform a drilling mud measurement during a drilling operation using the volume meter, wherein the drilling mud measurement is of a volume of at least some of the drilling mud used for the drilling operation; 
 (ii) determine that the drilling mud measurement is within an absolute mud value range; 
 (iii) determine that a differential between the drilling mud measurement and a reference drilling mud value exceeds a differential alarm threshold; and 
 (iv) generate an alarm in response to the differential between the drilling mud measurement and the reference drilling mud value exceeding the differential alarm threshold. 
   
     
     
         12 . The system of  claim 11 , wherein the computer program code further causes the at least one processor to display, on the display, traces respectively showing a history of drilling mud measurements and corresponding absolute mud value ranges. 
     
     
         13 . The system of  claim 11 , wherein the drilling mud measurement is of total mud volume for the drilling operation, and wherein the total mud volume excludes trip mud used for tripping operations. 
     
     
         14 . The system of  claim 11 , wherein the drilling mud measurement is of trip mud used for tripping operations and excludes drilling mud used for other drilling operations. 
     
     
         15 . The system of  claim 11 , wherein the differential alarm threshold is approximately 7 m 3  of drilling mud. 
     
     
         16 . The system of  claim 11 , wherein the computer program code further causes the at least one processor to receive user input explicitly request absolute mud value monitoring prior to determining that the drilling mud measurement is within the absolute mud value range and to determining that the differential between the drilling mud measurement and the reference drilling mud value exceeds the differential alarm threshold,
 wherein determining that the drilling mud measurement is within the absolute mud value range is performed in response to receiving the user input,   and wherein determining that the differential between the drilling mud measurement and the reference drilling mud value exceeds the differential alarm threshold is performed automatically in response to the user input.   
     
     
         17 . The system of  claim 11 , wherein the computer program code further causes the at least one processor to reset the reference drilling mud value in response to a user action indicative of user attention. 
     
     
         18 . The system of  claim 16 , wherein the user action comprises at least one of acknowledging the alarm, zeroing trip mud or total mud gain/loss, setting the reference drilling mud value to a current measured pit volume, or changing the absolute mud value range. 
     
     
         19 . The system of  claim 16 , wherein determining the differential is performed while alarm generation has been disabled by a user, wherein the computer program code further causes the at least one processor to enable the alarm generation in response to receiving user input to enable the alarm generation while the alarm generation is disabled, and wherein the alarm is generated after receiving the user input to enable the alarm generation and is based on the differential determined while the alarm generation was disabled. 
     
     
         20 . At least one non-transitory computer readable medium having stored thereon computer program code that is executable by at least one processor and that, when executed by the at least one processor, causes the at least one processor to perform a method for differential drilling mud measurement, the method comprising:
 (a) performing a drilling mud measurement during a drilling operation, wherein the drilling mud measurement is of a volume of at least some of the drilling mud used for the drilling operation;   (b) determining that the drilling mud measurement is within an absolute mud value range;   (c) determining that a differential between the drilling mud measurement and a reference drilling mud value exceeds a differential alarm threshold; and   (d) generating an alarm in response to the differential between the drilling mud measurement and the reference drilling mud value exceeding the differential alarm threshold.