Validation of Fracture Height and Density from Rapid Time-Lapse DAS VSP for use in Calculating Stimulated Rock Volume:A Case Study from Hereford Field,Colorado

摘要

Distributed acoustic sensing(DAS)inter-stage vertical seismic profiling(VSP)data were acquired during the stimulation of two horizontal shale wells in the Denver-Julesburg(DJ)Basin's Hereford field.These data were analyzed to obtain induced fracture heights and fracture densities for use in fracture modeling and Stimulated Rock Volume(SRV)calculations.Inverted inter-stage VSP(also referred to as rapid time-lapse DAS VSP)data,transformed to an anisotropic seismic velocity model via rock physics relationships,were used to estimate stage-by-stage fracture height and density.Comparison of fracture height from multiple sources confirm the validity of fracture height calculations for the Niobrara fiber well,and the deeper Codell fiber well.When combined with other independent diagnostics such as microseismic,tilt(microdeformation),seismic rock properties,pressure,and distributed acoustic/temperature sensing(DAS/DTS)data,these estimates are validated for use in developing an optimized completion plan,as well as for use in calculating stage-by-stage stimulated rock volumes.