Monitoring and diagnosing completions during hydraulic fracturing operations provides insights into the fracture geometry, interwell frac hits, and connectivity. Conventional monitoring methods (microseismic, pressure gauges, tracers, etc.) can provide a range of information about the stimulated rock volume but may often be limited in detail. Utilization of distributed acoustic sensing (DAS) as a fracture monitoring tool is growing; however, most of the applications have been limited to acoustic frequency bands of the DAS recorded signal.

This presentation will showcase some examples using the low-frequency band of the DAS signal to constrain hydraulic fracture geometry. DAS data were acquired in both offset horizontal and vertical monitor wells. In horizontal wells, DAS data records formation strain perturbations due to fracture propagation. Events like fracture opening and closing, stress shadow creation and relaxation, ball seating, and plug isolation can be clearly identified. In vertical wells, DAS responses agree with co-located pressure and temperature gauges and illuminate the vertical extent of hydraulic fractures. It will be shown that DAS data in the low-frequency band provide a powerful attribute to monitor small strain and temperature perturbations in or near the monitor wells. With different fiber monitor well designs, it is possible to measure the far-field fracture length, height, width, and density using cross-well DAS observations.

Registration for this event closes at 6:00 PM CDT on Monday, April 16, 2018.