Downhole DAS Observation of Guided Waves in a Shale Reservoir Generated by Perforation Shots

Summary We observe distributed acoustic sensing records of guided waves excited by perforation shots in a low-velocity shale layer. Thanks to the high spatial and temporal resolution of distributed acoustic sensing acquisition, unaliased high frequencies of up to 700 Hz can be observed. We analyze and validate the existence of such waves by comparing the recorded data with synthetic data computed using acoustic modeling as recorded in both the horizontal and the vertical segment of the well. These guided waves are trapped within the low-velocity organic shale reservoir and hold a tremendous potential for high-resolution imaging of it.