Numerical Solution for Height and Elongated Hydraulic Fractures

The authors are developing a simplified model of hydraulic fracture expansion which can predict height growth and bottomhole pressure behavior as a function of time when a blanket sand is stimulated. Leakoff is included. Illustrative results have been presented. The main limitation is that the height growth must be slow compared with the length extension (i.e., elongated fractures with aspect ratio about 5). At present the model works in a three-layer case in which the higher bounding stresses are symmetric about the payzone. This is being extended to the case in which the stresses are asymmetric. Meanwhile, an approximate solution is available when the asymmetric bounding stresses are not too different, but leakoff is not included. This has been used above to estimate fracture height growth in the Cozzette sand which will be stimulated as part of the Multi-Well Experiment.