Method for determining reservoir properties in a flowing well

Abstract

A technique facilitates monitoring a reservoir property in a flowing well ( 22 ). The technique utilizes deployment of a sensor system ( 42,66 ) along the wellbore outside of a wellbore commingled flow region. The sensor system is utilized while the well is flowing during production, and the measured formation property can be used to determine/evaluate production and other well characteristics.

1 . A method of monitoring a well, comprising:
 deploying a sensor system along a wellbore outside a wellbore commingled flow region; and   measuring a reservoir property with the sensor system while the well is producing.   
   
   
       2 . The method of  claim 1 , wherein measuring a reservoir property comprises directly determining individual reservoir layer pressures. 
   
   
       3 . The method of  claim 1 , further comprising utilizing the sensor system to determine the state of a gravel pack. 
   
   
       4 . The method of  claim 2 , wherein deploying the sensor system comprises deploying the sensor system at the periphery of the wellbore region defined by a surrounding gravel pack. 
   
   
       5 . The method of  claim 2 , wherein deploying the sensor system comprises deploying the sensor system outside of a well casing. 
   
   
       6 . The method of  claim 2 , wherein deploying the sensor system comprises deploying a fiber optic distributed sensing system. 
   
   
       7 . The method of  claim 2 , further comprising locating the sensor system in a groove along an exterior of a sand screen assembly to position the sensor system against a gravel pack. 
   
   
       8 . The method of  claim 7 , wherein locating the sensor system comprises locating the sensor system in the groove along the exterior of a screen cover in a shunt tube sand screen assembly. 
   
   
       9 . The method of  claim 7 , wherein locating the sensor system comprises locating an optical fiber sensor in the groove. 
   
   
       10 . A method of monitoring a subterranean reservoir, comprising:
 directly measuring reservoir layer pressures along a wellbore in a reservoir by deploying a sensor system at or outside a wellbore periphery; and   monitoring the reservoir layer pressures during production to determine depletion of reservoir intervals.   
   
   
       11 . The method of  claim 10 , wherein directly measuring reservoir layer pressures comprises measuring Joule-Thomson changes resulting from flow in the reservoir. 
   
   
       12 . The method of  claim 10 , wherein directly measuring reservoir layer pressures comprises deploying a multi-point sensor system. 
   
   
       13 . The method of  claim 10 , wherein directly measuring reservoir layer pressures comprises deploying a fiber optic distributed sensor. 
   
   
       14 . The method of  claim 10 , further comprising evaluating the quality of a surrounding gravel pack. 
   
   
       15 . The method of  claim 10 , wherein monitoring the reservoir layer pressures comprises continually monitoring cumulative Joule-Thomson changes to directly obtain reservoir pressure changes at multiple layers of the reservoir. 
   
   
       16 . The method of  claim 13 , wherein directly measuring reservoir layer pressures comprises locating the fiber optic distributed sensor in a groove along an exterior of a casing. 
   
   
       17 . The method of  claim 13 , wherein directly measuring reservoir layer pressures comprises locating the fiber optic distributed sensor in a groove along an exterior of a sand screen assembly to position the fiber optic sensor directly against a surrounding gravel pack. 
   
   
       18 . A method of monitoring a subterranean reservoir, comprising:
 determining a geothermal temperature of the reservoir at multiple depths along a wellbore;   deploying a fiber optic sensor along the wellbore in the reservoir outside of a commingled flow region of the wellbore; and   utilizing the fiber optic sensor to track changes in temperature relative to the geothermal temperature at the multiple depths along the wellbore during production.   
   
   
       19 . The method of  claim 18 , wherein deploying a fiber optic sensor comprises deploying a fiber optic distributed sensor. 
   
   
       20 . The method of  claim 19 , wherein deploying the fiber optic distributed sensor' comprises locating the fiber optic distributed sensor in a groove along an exterior of a casing. 
   
   
       21 . The method of  claim 19 , wherein deploying the fiber optic distributed sensor comprises locating the fiber optic distributed sensor in a groove along an exterior of a sand screen assembly to position the fiber optic sensor directly against a surrounding gravel pack. 
   
   
       22 . The method of  claim 18 , wherein utilizing the fiber optic sensor comprises directly determining reservoir layer pressures based on the changes in temperature. 
   
   
       23 . The method of  claim 18 , wherein deploying the fiber optic sensor comprises deploying the fiber optic sensor along a gravel pack. 
   
   
       24 . The method of  claim 23 , further comprising evaluating the state of the gravel pack via data obtained from the fiber optic sensor. 
   
   
       25 . The method of  claim 18 , further comprising adjusting production of well fluid based on changes detected via the fiber optic sensor.