Estimating fracture dimensions from microseismic data

摘要

Method for imaging of a hydraulic fracture generated by fluid injection. Microseismic data of the hydraulic fracture treatment is collected and analyzed for the location and magnitude of microseismic events. The seismic energy or moment of the micro seismic events is calculated (11) and plotted with the size of events scaled by their energy or moment (12). The cumulative seismic energy or moment is calculated as a function of distance from the perforation point (13). The fracture dimensions are determined by applying cut-offs, based on selected criteria, to the cumulative energy or moment estimates (14).

主权项

1. A method for hydraulic fracturing with microseismic monitoring of a hydraulic fracture caused by stimulation of the fracture by fluid injection at a perforation location, said method comprising:
obtaining microseismic data representing the fracture stimulation; locating the microseismic events in the microseismic data, and determining their magnitudes; using a computer to transform seismic data, comprising said microseismic events, into a model of the subsurface showing fracture dimensions caused by the fluid injection, wherein the computer performs steps of,
calculating seismic energy or seismic moment of the microseismic events from their magnitudes,calculating cumulative seismic energy or moment as a function of distance from the perforation location, anddetermining one or more fracture dimensions from the calculated cumulative seismic energy or moment as a function of distance, wherein the determining includes selecting a cutoff criterion and applying the cutoff criterion to the calculated cumulative seismic energy or moment as a function of distance, and the selected cutoff criterion is a selected percentage of maximum calculated cumulative seismic energy or moment; and injecting fluid into the fracture until the fracture dimensions meet or exceed predetermined dimensions.