Insights Into Hydraulic Fracture Growth Gained From a Joint Analysis of Seismometer?Derived Tilt Signals and Acoustic Emissions

Hydraulic fracturing is performed to enhance rock permeability, for example, in the frame of geothermal energy production or shale gas exploitation, and can potentially trigger induced seismicity. The tracking increased permeabilities extent often based on microseismic event distribution within stimulated volume, but it debated whether activity adequately depicts fracture formation. We are able record tilt signals that appear as long-period transients (180 s) two broadband seismometers installed close (17–72 m) newly formed, meter-scale hydraulic fractures. With this observation, we overcome limitations monitoring alone verify mapping. Our analysis first time combines a catalog previously analyzed acoustic emissions ([AEs] durations 20 ms), indirectly mapping fractures, with unique signals, provide independent, direct insights into deformation rock. allows identify different phases process including (re)opening, growth, aftergrowth Further, helps differentiate between formation complex networks single macrofractures, validates AE findings contribute better understanding processes, which may help reduce fluid-injection-induced seismicity validate efficient