Modelling Study on Geothermal Well under High Geostress

Model analysis of geothermal well in formation with high geostress was presented in the paper. Stress, stain and displacement of the rock in the wall of geothermal well were discussed in detail. The results of theoretical model analysis show that: (1) Axial stress, strain and displacement increase with the increasing of the depth of the well, while the effects of the depth on radial strain and displacement, and circumferential displacement are small; (2) The size of radial stress has nothing to do with the azimuth, while the three components of the strain changes with the azimuth angle by the cosine law and the phase difference between circumferential strain and radial & axial strain is 180 degrees; (3) Axial displacement changes with the azimuth angle according to the cosine law, while circumferential displacement changes with the azimuth angle according to the sine law and its amplitude increases with the increasing of azimuth angle; (4) The three components of stress and strain, axial and circumferential displacement do not change with the change of well diameter.