Multiple, mechanically-activated, sliding-sleeve fracports is a common completion used for horizontal wells in unconventional reservoirs. Characteristic seismic signals have been observed at approximately the same time as pressure spikes associated with balls dropped to open the sliding sleeves. The ‘ball drop’ seismic signals are high amplitude, low frequency, multiple discrete events with a short period of time, with each event locating at the fracport. The seismic radiation characteristics are consistent with an axial displacement along the treatment well. The seismic signals are attributed to the sleeve sliding open, which results in sufficient energy to account for the high amplitude signals. The occurance of the ball drop events can therefore be used to diagnose if the ball seated and the sleeve opened at the expected location, and along with the pressure and microseismic response can be used to validate the expected actions of the completion. Several case studies are also presented illustrating successful stage isolation with proper completion operation, response of the sleeve not opening properly and stage overlap associated with both hydraulically connected fracture networks in the reservoir and connected fracture ports.

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