Laboratory-Scale Hydraulic Fracturing: Experiment and Numerical Modeling

摘要

Laboratory-scale experiments are an important method for improving understanding of the hydraulic fracturing process under controlled circumstances, even though it is difficult to realistically simulate downhole conditions in a laboratory. Laboratory-scale experiments can also help determine if a numerical model can be used as a predictive tool for hydraulic fracturing analysis. This paper discusses both experimental and numerical modeling performed for a hydraulic fracturing test on a 30x30x45 cm specially designed cement block. The experiment was conducted using a true poly-axial testing system, and was designed to obtain data regarding the behavior of a hydraulically induced fracture and its interaction with a pre-existing fracture. The experimental data can provide insight to better understand the mechanisms of fracture initiation, propagation, and interaction. A computational algorithm was used to perform numerical modeling for the laboratory fracturing test. The computational algorithm tightly couples geomechanics and fluid dynamics models while providing fracture propagation criteria for hydraulically induced fractures. The numerical simulation results are compared in this work to experimental results, illustrating that the numerical model is capable of describing the interaction between pre-existing fractures. It also can help improve the understanding of complex fracture growth in reservoir conditions.