Patent ID: 8631867
Filing Date: 2014-01-21
Classification: E21B

Abstract:
1. A method for monitoring, a fracturing operation in a target well comprising: a. extending at least two spaced apart seismic sensors in a tubing string to a first position in a well offset from the target well; b. circulating a coolant fluid from the surface through the tubing string for a predetermined cooling time to cool the at least two seismic sensors; c. retracting the tubing string to a second uphole position such that the cooled at least two seismic sensors are exposed in the offset well and stopping the coolant flow during a predetermined heat up time; d. sensing a seismic signal emitted during the fracturing operation in the target well while the coolant circulation is stopped during the predetermined heat up time; e. re-extending the tubing string over the at least two seismic sensors at the first position in the well after the predetermined heat up time; f. restarting circulation of the cooling fluid from the surface through the tubing string for the predetermined cooling time to cool the at least two seismic sensors; g. retracting the tubing string to the second uphole position such that the cooled at least two seismic sensors are exposed in the offset well and stopping the coolant flow during a predetermined heat up time; h. sensing the seismic signal emitted during the fracturing operation in the target well while the coolant circulation is stopped during the predetermined heat up time; and i. repeating steps e-h until the fracturing operation is complete.