Hydraulic fracture conductivity inferred from tube wave reflections

Abstract

The conductivity of hydraulic fractures in a multistage plug-and-perf stimulation treatment is estimated from tube wave reflections. Tube waves are generated at the wellhead, travel down the well, reflect off of the set of fractures in the current stage, and return to the wellhead where they are recorded. The data are interpreted using a model that accounts for Darcy flow within the proppant-filled fractures, elastic compliance of the fractures, and coupling between the fractures and borehole, ultimately yielding a complex-valued, frequency-dependent reflection coefficient. Comparisons between the model and data are made in both the time domain (i.e., full waveform inversion) and frequency domain (i.e., matching frequencies and quality factors of resonant modes of the borehole-fracture system). The inferred conductivity is consistent with fractures having widths ~ 4 mm and permeabilities ~100 D, though only the product of these two quantities is uniquely constrained. This procedure provides a means to efficiently monitor fracture properties during and after stimulation treatments. Presentation Date: Thursday, September 28, 2017 Start Time: 10:10 AM Location: 362D Presentation Type: ORAL