Wellbore influx detection with drill string distributed measurements

Abstract

A method for detecting a wellbore influx with drill string distributed measurements includes obtaining a first annular measurement from a first sensor disposed on a drill string. The method also includes obtaining a second annular measurement from a second sensor disposed on the drill string and computing a gradient of a first interval defined by the first and second sensors. Finally, the method includes detecting a wellbore influx based on the gradient and the first and second annular measurements.

What is claimed is: 
     
         1 . A method for detecting a wellbore influx with drill string distributed measurements comprising:
 obtaining a first annular measurement from a first sensor disposed on a drill string;   obtaining a second annular measurement from a second sensor disposed on the drill string;   computing a gradient of a first interval defined by the first and second sensors; and   detecting a wellbore influx based on the gradient and the first and second annular measurements.   
     
     
         2 . The method of  claim 1  further comprising:
 obtaining a third annular measurement from a third sensor disposed on the drill string; 
 wherein a plurality of intervals are defined between the first, second, and third sensors; 
 further computing at least one gradient over the plurality of intervals; and 
 detecting the wellbore influx based on the at least one gradient and the first, second, and third annular measurements. 
 
     
     
         3 . The method of  claim 1  wherein the first and second annular measurements include pressure, and further comprising measuring a drill string bore pressure from a bore sensor disposed on the drill string. 
     
     
         4 . The method of  claim 3  further comprising:
 observing a decrease in the first or second annular pressure measurements; 
 observing a decrease in the pressure gradient of the first interval; and 
 detecting the wellbore influx based on the decreases. 
 
     
     
         5 . The method of  claim 4  further comprising locating the wellbore influx where the decreases are observed. 
     
     
         6 . The method of  claim 5  further comprising observing the decreases above a BOP and determining that the wellbore influx is above the BOP. 
     
     
         7 . The method of  claim 6  further comprising observing a pressure or gradient decline rate within a riser. 
     
     
         8 . The method of  claim 7  further comprising diverting a wellbore fluid if the decline rate is at or above a pre-determined rate. 
     
     
         9 . The method of  claim 7  further comprising lining up a mud-gas separator if the decline rate is below a pre-determined rate. 
     
     
         10 . The method of  claim 5  further comprising observing the decreases below a BOP and determining that the wellbore influx is below the BOP. 
     
     
         11 . The method of  claim 10  further comprising observing a pressure below the BOP, and:
 if the below-BOP pressure is increasing, determining that the BOP has actuated and has sealed an annulus, or 
 if the below-BOP pressure is not increasing, actuating the BOP or determining an inadequate dealing of the annulus. 
 
     
     
         12 . The method of  claim 3  wherein the detecting the wellbore influx further comprises measuring an increasing annular pressure below a BOP in a closed position and measuring a decreasing annular pressure and a decreasing annular pressure gradient above the closed BOP. 
     
     
         13 . The method of  claim 1  further comprising:
 pumping a kill fluid into the drill string; 
 identifying measurement sensors above and below a casing shoe; 
 computing an annular pressure at the casing shoe by interpolating measurements from the sensors above and below the casing shoe; and 
 if the annular casing shoe pressure is below a pre-determined threshold, increasing the pumping of the kill fluid; or if the annular casing shoe pressure is above the pre-determined threshold, reducing the pumping of the kill fluid. 
 
     
     
         14 . The method of  claim 1  further comprising:
 pumping a kill fluid into a kill line to force a wellbore influx and original wellbore fluid into a formation; 
 observing a pressure gradient increase in a sensor interval below a BOP; and 
 detecting progress of the kill fluid in an annulus based on the pressure gradient increase. 
 
     
     
         15 . The method of  claim 1  wherein the first annular measurement comprises a first annular temperature measurement and the second annular measurement comprises a second annular temperature measurement. 
     
     
         16 . The method of  claim 3  further comprising:
 observing an increase in the first or second annular temperature measurements; 
 observing an increase in the temperature gradient of the first interval; and 
 detecting the wellbore influx based on the increases. 
 
     
     
         17 . The method of  claim 16  further comprising locating the wellbore influx where the increases are observed. 
     
     
         18 . The method of  claim 17  further comprising:
 observing an annular temperature decrease; 
 observing an annular temperature gradient decrease; and 
 detecting that gas is breaking out of solution and has advanced to the locations where the decreases are observed. 
 
     
     
         19 . The method of  claim 18  further comprising observing the decreases above a BOP and determining that the wellbore influx is above the BOP. 
     
     
         20 . The method of  claim 19  further comprising observing a temperature or temperature gradient decline rate within a riser. 
     
     
         21 . The method of  claim 20  further comprising diverting a wellbore fluid if the decline rate is at or above a pre-determined rate. 
     
     
         22 . The method of  claim 20  further comprising lining up a mud-gas separator if the decline rate is below a pre-determined rate. 
     
     
         23 . The method of  claim 18  further comprising observing the decreases below a BOP and determining that the wellbore influx is below the BOP. 
     
     
         24 . The method of  claim 23  further comprising observing a temperature below the BOP, and:
 if the below-BOP temperature is increasing, determining that the BOP has actuated and has sealed an annulus, or 
 if the below-BOP temperature is not increasing, actuating the BOP or determining an inadequate dealing of the annulus. 
 
     
     
         25 . The method of  claim 1  wherein the first annular measurement comprises a first annular flow rate measurement and the second annular measurement comprises a second annular flow rate measurement. 
     
     
         26 . The method of  claim 25  further comprising:
 observing an increase in the first or second annular flow rate measurements; 
 observing an increase in the flow rate gradient of the first interval; and 
 detecting and locating the wellbore influx based on the increases. 
 
     
     
         27 . A method for detecting a wellbore influx with drill string distributed measurements comprising:
 obtaining a first strain measurement from a first sensor disposed on a drill string;   obtaining a second strain measurement from a second sensor disposed on the drill string;   computing a gradient of a first interval defined by the first and second sensors; and   detecting a wellbore influx based on the gradient and the first and second strain measurements.   
     
     
         28 . The method of  claim 27  further comprising:
 observing an increase in the first or second drill string strain measurements; 
 observing a change or a decrease in the drill string gradient of the first interval; and 
 detecting and locating the wellbore influx based on the increase and the decrease. 
 
     
     
         29 . The method of  claim 28  further comprising:
 actuating a BOP; and 
 if strain measurement decreases are observed below the BOP, determining that the BOP has actuated and has sealed an annulus, or 
 if strain measurement decreases are not observed below the BOP, determining that the BOP has not actuated or determining an inadequate sealing of the annulus. 
 
     
     
         30 . A method for detecting a wellbore influx with drill string distributed measurements comprising:
 providing a plurality of sensors distributed on a drill string with an electromagnetic network;   identifying a plurality of intervals defined between two sensors that are adjacent or have intervening sensors;   obtaining an absolute measurement at two or more of the sensors;   computing a gradient for the measurement of the plurality of intervals; and   detecting a wellbore influx based on the gradient and the absolute measurements.   
     
     
         31 . The method of  claim 30  wherein the measurement includes at least one of pressure, temperature, flow rate, or drill string strain. 
     
     
         32 . The method of  claim 4  further comprising:
 observing a decrease in the bore pressure; and 
 detecting the wellbore influx based on the decreases in the first or second annular pressure measurements, the pressure gradient of the first interval, and the bore pressure. 
 
     
     
         33 . The method of  claim 1  further comprising:
 pumping a kill fluid into the drill string; 
 identifying a measurement sensor at or immediately adjacent to a casing shoe; 
 computing an annular pressure at the casing shoe by based on a measurement from the sensor; and 
 if the annular casing shoe pressure is below a pre-determined threshold, increasing the pumping of the kill fluid; or 
 if the annular casing shoe pressure is above the pre-determined threshold, reducing the pumping of the kill fluid.