Filling in the Gap: Capturing the Full Scaling Relationships of Hydraulic Fracturing

Seismicity associated with hydraulic fracturing can range in magnitude up to and beyond M3, large enough in many cases to be felt on surface. These higher magnitude events are in contrast to the smaller magnitude events that are normally used to characterize the efficacy of fracture treatments, as they can represent the activation of structures on the scale lengths of hundreds of meters, whereas the microseismicity (below M0) in the reservoir is associated with the activation of structures up to the scale of 10s of m. To accurately characterize events activating structures of intermediary lengths, i.e. between 10 m and 100 m, deploying instruments at or near the reservoir level, and low-frequency instruments at shallower depths and on the surface will help determine accurate source parameters for events not only one the surface, but also for events not necessarily strong enough to propagate clearly to the surface but high enough magnitude to saturate typical 15 Hz downhole geophones.