Arrangement and method for detecting fluid influx and/or loss in a well bore

Abstract

An arrangement and method for more accurately detecting well bore fluid kicks and/or losses by coupling a fluid flow measurement device to a substantially vertical tubular, such as a bell nipple or marine riser, to more accurately determine the flow rate of fluid flowing out of the well bore. Well bore fluid kicks and/or fluid losses are preferably detected by comparing the determined flow rate of fluid flowing out of the well bore and the flow rate of fluid injected into the well bore for any difference indicative of a well bore fluid kick or loss event.

What is claimed is: 
     
         1 . An arrangement ( 10 ,  12 ) for detecting a well bore fluid kick or loss comprising:
 a drill string ( 30 ) having a drill bit ( 34 ) at a distil end portion arranged and designed to drill a well bore ( 14 ), said drill bit creating a well bore annulus ( 42 ) between said drill string and an inner surface of said well bore as said well bore is drilled;   a blowout preventer ( 50 ) in fluid communication with said well bore annulus and arranged and designed to close said well bore annulus from atmosphere in response to an indication of a fluid influx event;   a substantially vertical tubular ( 40 ) fluidly coupled to said blowout preventer and in fluid communication therewith, said substantially vertical tubular having a flow line ( 60 ) fluidly coupled to an outlet ( 38 ) thereof, said substantially vertical tubular and said flow line arranged and designed to carry fluid exiting said well bore annulus through said blowout preventer; and   a flow measurement device ( 20 ) coupled to said substantially vertical tubular between said blowout preventer and said flow line, said flow measurement device arranged and designed to determine a flow rate of fluid flowing through said substantially vertical tubular.   
     
     
         2 . The arrangement of  claim 1  wherein,
 said substantially vertical tubular is a bell nipple. 
 
     
     
         3 . The arrangement of  claim 1  wherein,
 said substantially vertical tubular is a marine riser. 
 
     
     
         4 . The arrangement of  claim 1  wherein,
 said flow measurement device is an ultrasonic flow rate meter. 
 
     
     
         5 . The arrangement of  claim 4  wherein,
 said ultrasonic flow rate meter has at least two transducers ( 22 ). 
 
     
     
         6 . The arrangement of  claim 5  wherein,
 said ultrasonic flow rate meter has two transducers ( 22 ) which are disposed on said tubular and separated from each other by a vertical distance ( 24 ). 
 
     
     
         7 . The arrangement of  claim 6  wherein,
 said vertical distance is greater than a length of a drill pipe connection ( 32 ). 
 
     
     
         8 . The arrangement of  claim 1  further comprising,
 another flow rate measurement device ( 78 ) coupled to a fluid injection line ( 76 ) in fluid communication with said drill string disposed in said well bore, said another flow rate measurement device arranged and designed to determine another flow rate of fluid flowing through said fluid injection line. 
 
     
     
         9 . A method for detecting a well bore fluid kick or loss comprising the steps of:
 coupling a flow rate measurement device ( 20 ) to a substantially vertical tubular ( 40 ), said substantially vertical tubular fluidly coupled to a blowout preventer ( 50 ) which is in fluid communication with a well bore ( 14 ), said substantially vertical tubular having a flow line ( 60 ) coupled to an outlet ( 38 ) thereof, said substantially vertical tubular and said flow line arranged and designed to carry fluid exiting said well bore through said blowout preventer, said flow rate measurement device arranged and designed to determine a flow rate of fluid flowing through said substantially vertical tubular between said blowout preventer and said flow line;   determining said flow rate of fluid flowing through said substantially vertical tubular using said flow rate measurement device coupled to said substantially vertical tubular between said blowout preventer and said flow line; and   comparing said determined flow rate of fluid flowing through said substantially vertical tubular and a determined flow rate of fluid flowing into said wellbore for any difference indicative of a well bore fluid kick or loss.   
     
     
         10 . The method of  claim 9  wherein,
 said substantially vertical tubular is a bell nipple. 
 
     
     
         11 . The method of  claim 9  wherein,
 said substantially vertical tubular is a marine riser. 
 
     
     
         12 . The method of  claim 9  wherein,
 said flow rate measurement device is an ultrasonic flow rate meter. 
 
     
     
         13 . The method of  claim 12  wherein,
 said ultrasonic flow rate meter has at least two transducers ( 22 ). 
 
     
     
         14 . The method of  claim 13  wherein,
 said ultrasonic flow rate meter has two transducers ( 22 ) which are disposed onto said substantially vertical tubular and separated from each other by a vertical distance ( 24 ). 
 
     
     
         15 . The method of  claim 14  wherein,
 said vertical distance is greater than the length of a drill pipe connection ( 32 ). 
 
     
     
         16 . The method of  claim 9  further comprising the steps of,
 coupling another flow rate measurement device ( 78 ) to a fluid injection line ( 76 ) in fluid communication with a drill string ( 30 ) disposed in said well bore, said another flow rate measurement device arranged and designed to determine another flow rate of fluid flowing through said fluid injection line into said drill string, and 
 determining said another flow rate of fluid flowing through said fluid injection line into said drill string using said another flow rate measurement device, and wherein 
 said determined flow rate of fluid flowing into said wellbore is equal to said another flow rate of fluid flowing through said fluid injection line into said drill string. 
 
     
     
         17 . An arrangement ( 10 ,  12 ) for measuring flow rate of fluid exiting a well bore, said arrangement comprising:
 an ultrasonic flow rate meter ( 40 ) having at least two transducers ( 22 ) disposed about a substantially vertical tubular ( 40 ), said substantially vertical tubular coupled to a wellhead ( 52 ) and in fluid communication with a well bore ( 14 ), said at least two transducers having a vertical separation ( 24 ) therebetween and arranged and designed to determine a flow rate of fluid passing through said substantially vertical tubular from said well bore.   
     
     
         18 . The arrangement of  claim 17  wherein,
 said substantially vertical tubular is a bell nipple. 
 
     
     
         19 . The arrangement of  claim 17  wherein,
 said substantially vertical tubular is a marine riser. 
 
     
     
         20 . The arrangement of  claim 17  wherein,
 said vertical separation is greater than the length of a drill pipe connection ( 32 ).