Subsurface flow control for downhole operations

Abstract

A method comprises determining a first value of a formation attribute of a first zone based on a measurement by a downhole gauge, wherein the formation attribute comprises at least one of a pressure and a flow rate. An opening of a choke valve is adjusted to a first position to control flow of at least one of gas and liquid coming from the first zone based on the first value of the formation attribute. At least one of a pressure buildup and a pressure falloff of the first zone is determined. The opening of the choke valve is adjusted to a second position based on the at least one of the pressure buildup and the pressure falloff of the zone.

What is claimed is: 
     
         1 . A system comprising:
 a downhole gauge to be positioned in a wellbore drilled into a subsurface formation, the downhole gauge to measure a formation attribute of a zone of a number of zones in the subsurface formation;   a choke valve to control flow of at least one of gas and liquid from the zone, wherein the formation attribute comprises at least one of a pressure and a flow rate of the zone;   a processor; and   a computer-readable medium having instructions stored thereon that are executable by the processor to cause the processor to,
 determine a first value of the formation attribute of the zone based on a measurement by the downhole gauge; 
 adjust an opening of the choke valve to a first position based on the first value of the formation attribute; 
 determine at least one of a pressure buildup and a pressure falloff of the zone; and 
 adjust the opening of the choke valve to a second position based on the at least one of the pressure buildup and the pressure falloff of the zone. 
   
     
     
         2 . The system of  claim 1 ,
 wherein the instructions further comprise instructions executable by the processor to cause the processor to determine a productivity factor of the zone based on the at least one of the pressure buildup and pressure falloff of the zone, and   wherein the instructions executable by the processor to cause the processor to adjust the opening of the choke valve to the second position comprise instructions executable by the processor to cause the processor to adjust the opening of the choke valve to the second position based on the productivity factor.   
     
     
         3 . The system of  claim 2 , wherein the instructions executable by the processor to cause the processor to adjust the opening of the choke valve comprise instructions executable by the processor to cause the processor to determine a port setting of the choke valve based on at least one of the first value of the formation attribute and the productivity factor. 
     
     
         4 . The system of  claim 2 , wherein the productivity factor comprises at least one of a skin value of the zone, a productivity index of the zone, an injectivity index of the zone, and a flux of the zone. 
     
     
         5 . The system of  claim 1 , wherein the instructions executable by the processor to cause the processor to adjust the opening of the choke valve to a first position further comprise instructions executable by the processor to cause the processor to determine a second value of the formation attribute of the zone based on the adjustment of the opening of the choke valve to the first position. 
     
     
         6 . The system of  claim 5 , wherein the instructions executable by the processor to cause the processor to adjust the opening of the choke valve to the second position comprise instructions executable by the processor to cause the processor to adjust the opening of the choke valve to the second position based on a determination that the second value of the formation attribute is within a boundary. 
     
     
         7 . The system of  claim 1 ,
 wherein the instructions further comprise instructions executable by the processor to cause the processor to determine initial conditions for the zone and establish normal readings of conditions for the zone,   wherein the instructions executable by the processor to cause the processor to adjust the opening of the choke valve to the first position is based on a determination that the initial conditions are within the normal readings.   
     
     
         8 . The system of  claim 1 , further comprising instructions executable by the processor to cause the processor to adjust to the first position the opening of the choke valve to adjust a direction of flow of at least one of gas and liquid in the zone. 
     
     
         9 . A method comprising:
 determining a first value of a formation attribute of a first zone based on a measurement by a downhole gauge, wherein the formation attribute comprises at least one of a pressure and a flow rate;   adjusting an opening of a choke valve to a first position to control flow of at least one of gas and liquid coming from the first zone based on the first value of the formation attribute;   determining at least one of a pressure buildup and a pressure falloff of the first zone; and   adjusting the opening of the choke valve to a second position based on the at least one of the pressure buildup and the pressure falloff of the first zone.   
     
     
         10 . The method of  claim 9 , further comprising determining a productivity factor of the zone based on the at least one of the pressure buildup and pressure falloff of the zone, wherein adjusting the opening of the choke valve to the second position comprises adjusting the opening of the choke valve to the second position based on the productivity factor. 
     
     
         11 . The method of  claim 10 , wherein adjusting the opening of the choke valve comprises determining a port setting of the choke valve based on at least one of at least one of the formation attribute and the productivity factor. 
     
     
         12 . The method of  claim 10 , wherein the productivity factor comprises at least one of a skin value of the first zone, a productivity index of the first zone, an injectivity index of the first zone, and a flux of the first zone. 
     
     
         13 . The method of  claim 9 , wherein adjusting the opening of the choke valve to the first position further comprises determining a second value of the formation attribute of the zone based on adjusting the opening of the choke valve to the first position. 
     
     
         14 . The method of  claim 13 , wherein adjusting the opening of the choke valve to the second position comprises adjusting the opening of the choke valve to the second position based on determining that the second value of the formation attribute is within a boundary. 
     
     
         15 . The method of  claim 9  further comprising:
 determining initial conditions for the first zone; and 
 establishing normal readings of conditions for the first zone, 
 wherein adjusting the opening of the choke valve to the first position is based on determining that the initial conditions are within the normal readings. 
 
     
     
         16 . The method of  claim 9  further comprising adjusting to the first position the opening of the choke valve to adjust a direction of flow of at least one of gas and liquid in the first zone. 
     
     
         17 . One or more non-transitory machine-readable storage media having program code executable by a processor to cause the processor to:
 obtain a formation attribute of a zone of a well drilled into a subsurface formation, wherein the formation attribute comprises at least one of a pressure and a flow rate;   adjust an opening of a choke valve to a first position to control flow of at least one of gas and liquid coming from the zone based on a value of the formation attribute;   determine at least one of a pressure buildup and a pressure falloff of the zone; and   adjust the opening of the choke valve to a second position based on the at least one of the pressure buildup and the pressure falloff of the zone.   
     
     
         18 . The non-transitory machine-readable storage media of  claim 17 , further comprising program code executable by the processor to cause the processor to determine a productivity factor of the zone based on the at least one of the pressure buildup and pressure falloff of the zone, wherein the program code to adjust the opening of the choke valve to the second position comprises program code to adjust the opening of the choke valve to the second position based on the productivity factor. 
     
     
         19 . The non-transitory machine-readable storage media of  claim 18 , wherein the program code to adjust the opening of the choke valve comprises program code to calculate a port setting of the choke valve based on at least one of at least one of the formation attribute and the productivity factor. 
     
     
         20 . The non-transitory machine-readable storage media of  claim 17 , wherein the program code to adjust the opening of the choke valve to the second position comprises program code to adjust the opening of the choke valve to the second position based on a determination that the value of the formation attribute is within a boundary.