System and method for downhole inorganic scale monitoring and intervention in a production well

Abstract

An apparatus for estimating an ambient environment at which inorganic scale will form in a downhole fluid includes a stress chamber disposed in a borehole in a production zone at a location within a specified range of maximum pressure and configured to receive a sample of the fluid from the production zone and to apply an ambient condition to the sample that causes the formation of inorganic scale. An inorganic scale sensor is configured to sense formation of inorganic scale within the chamber and an ambient environment sensor is configured to sense an ambient environment within the chamber at which the formation of inorganic scale occurs. The apparatus further includes a processor configured to receive measurement data from the inorganic scale sensor and the ambient environment sensor and to identify the ambient environment at which the formation of inorganic scale occurs.

What is claimed is: 
     
         1 . A method for estimating a margin to formation of inorganic scale in a fluid produced from a production zone of a borehole penetrating the earth, the method comprising:
 producing a formation fluid in the production zone;   collecting a sample of the formation fluid in the production zone and disposing the sample in a stress chamber disposed in the production zone;   preconditioning the sample by separating phases of the sample;   applying an ambient condition to the sample that causes the formation of inorganic scale using the stress chamber; and   estimating the margin for a location in a production path from the production zone to a surface of the earth by calculating a difference between an ambient environmental condition at the location and the ambient condition that causes the formation of inorganic scale in the stress chamber using a processor.   
     
     
         2 . The method according to claim  18 , wherein preconditioning comprises separating phases of the fluid sample by at least one of decreasing pressure within the sample chamber, gravity separation, and membrane separation. 
     
     
         3 . The method according to claim  18 , further comprising;
 identifying when the margin decreases below a set point using a supervisory system that obtains input from a downhole pressure and temperature sensor disposed in the production zone, and   at least one of (a) injecting chemicals into the production zone using a chemical injection system disposed at the surface and a chemical injection mandrel disposed in the production zone and (b) operating an inflow control valve disposed in the production zone.   
     
     
         4 . A non-transitory computer-readable medium comprising instructions for calculating where inorganic scale formation would form in a production fluid in a product path from downhole to a surface of the earth which when executed by a computer implement a method comprising:
 receiving an ambient condition at which inorganic scale forms in a sample of the production fluid in a stress chamber disposed in a production zone at a location within a specified range of maximum pressure, the stress chamber being configured to apply the ambient condition to the sample;   calculating a difference between the ambient condition applied by the stress chamber and an ambient environmental condition at points along the production path; and   identifying those points along the production path where the difference is less than a selected setpoint.