The cracks are generated by high pressure gas produced from burning a propellant. High energy gas fracturing (HEGF) is a technique to stimulate wellbores by producing several radial cracks around the holes. They are also consistent with the theory that the final crack length is mainly determined by the gas pressure rather than the initial crack length produced by the stress waves. Considering that the level of uncertainty is very high in these types of engineering problems, the results show a good agreement with the experimental data.
Sensitivity analyses are performed on the main effective parameters. To evaluate the proposed algorithm, two field tests are simulated and the unknown parameters are determined through calibration. The fractured medium is modeled with the extended finite element method, and the stress intensity factor is calculated by the simple, though sufficiently accurate, displacement extrapolation method. The gas flow through the cracks is assumed as a one-dimensional transient flow, governed by equations of conservation of mass and momentum. In this paper, a numerical algorithm is proposed to quantitatively simulate propagation of these fractures around a pressurized hole as a quasi-static phenomenon. High energy gas fracturing is a simple approach of applying high pressure gas to stimulate wells by generating several radial cracks without creating any other damages to the wells.
0 kommentar(er)
