A Bullhead Refrac Application - Using Active Acoustic Pulses to Measure Diverter Effectiveness

During a bullhead refrac treatment, an Eagle Ford operator utilized active acoustic pulses to measure diverter effectiveness while continuously pumping. The goal was to determine if the fluid point of entry along the lateral would change after the diverter material seated on the perforations. The bullhead refrac treatment consisted of 52 sand ramps with planned diverter drops after each ramp. Active acoustic pulses were taken at the end of every sand ramp to identify if fluid point of entry was changing along the wellbore as a result of the diverter material. The acoustic pulses and return signals were captured with a hydrophone sensor for optimal signal quality. The return signal comes from the first encountered, lowest impedance point and represents fluid point of entry in the well. Subsequently, forward acoustic modeling was conducted to simulate acoustic responses from different fracture sizes and their corresponding acoustic signatures. Over 300 acoustic pulses were taken throughout the refrac treatment. Analysis of all the acoustic return signals indicated that a dominant fracture system was created or previously existed around the heel segment of the lateral and the fluid point of entry did not change throughout the duration of the refrac, indicating diverter was not effective. This paper will show that the use of acoustics gives an operator real-time ground truth about the location of the fluid point of entry and will allow them to make changes to optimize the refrac operation during a stage.