Study Of Simulating Stress Determination Technique By Hydraulic Fracturing Method

Based on the large quantities of stress determination tests by hydraulic fracturing in laboratory, many reliable experiment data were obtained and meanwhile some new conclusions were brought forward. The tests were conducted to simulate and investigate the effects of varying borehole inclination with respect to the fracturing and to investigate the effects of varying pressurization flow rates to the reopening tests. Based on the transformation and simplification of the specimens, computation fomula of maximum principal stress and rock tensile intensity were deduced through the analysis of elasticity mechanics method. In order to verify the experimental results and data, the procedures of fracturing were simulated by using the three-dimensional stress analysis coupled with two-dimensional flow analysis, both analysis being through the finfte element method. Displacements and flow rates were achived at one time. Conjugate gradient method were choosed to solve the large sparse matrix equations induced by the FEM and computer language FORTRAN was used to programme the numerical simulation system software.