The portability of the personal computer together with the integrated software package, HFDAP (HydroFrac Data Analysis Program), designed specifically for for identifying the key test parameters and stress calculations, enable the field practitioner to perform stress calculations on site.

HFDAP-HydroFrac Data Analysis Program

Presently included are the pressure-decay-rate vs. pressure(dp/dt), and the pressure vs. flowrate methods (pq). The fracture reopening pressure is determined using a numerical superposition routine of the pressure-time curves during fracture initiation and fracture reopening or by the dP/dQ method. The orientation of the fracture is determined by circular statistics or by sinusoidal curve fitting depending on whether the fracture is vertical or inclined, respectively.

The HFDAP also includes HTPF stress calculation suggested by Cornet and Valette (1984). A theoretical relationship between the fracture normal stress and the shut-in pressure in inclined fracture plane is used to calculate the state of stress.