Determination of Rock Mass Deformation Modulus During Hydraulic Fracturing

摘要

This paper presents the results from prototype testing of a new device developed to determine the rock mass deformation modulus during hydraulic fracturing stress measurements. The tool combines a modified US Bureau of Mines borehole deformation gage and standard hydraulic fracturing straddle packers to allow displacement measurements of the borehole wall along the diametrical axes in the pressurized test interval. The deformation modulus is evaluated through utilization of a closed-form elastic solution for a thick-walled cylinder, and the magnitudes and orientations of the in situ stress field are concurrently determined by conventional methods. Enhancement of hydraulic fracturing data interpretation may also be possible by using borehole displacement measurements to monitor induced fracture propagation and improve the definitiion of breakdown, fracture reopening, and shut-in pressures. 13 refs., 7 figs., 1 tab. (ERA citation 10:038883)