高压水射流射孔过程及机理研究

Study on progress and mechanism of high pressure water jet perforation

采用非线性动力有限元法和岩石动态损伤模型对高压水射流射孔过程及机理进行了模拟研究,并依据所给出的岩石孔隙度演化模式,分析了高压水射流射孔对岩石渗透性的影响。结果表明,高压水射流具有很强的破岩能力,卸载及射流冲击所产生的拉伸破坏是水射流破岩的主要形式,受岩石损伤发展的影响,随着与孔眼轴线距离的减小,岩石的孔隙度逐渐增大,而岩石的强度则呈减小趋势。分析结果首次从定量层面揭示了高压水射流射孔优于现有聚能射孔的机理。

The progress and mechanism of high pressure water jet perforation were simulated with nonlinear FEM and dynamic rock damage model. The evolvement of rock porosity was analyzed with the presented theoretical model. The numerical results show that the high pressure water jet has strong breaking rock ability; and the main damage behavior under water jet is tensile damage caused by the rock unload and the jet impacting. The porosity of rock increases while rock strength decrease with the decrease of distance between the axes of rock broken hole and the rock around the hole wall for the rock damage development. The study results have revealed the mechanism that high pressure water jet perforation is superior to the cumulative jet perforation from the quantitative aspect for the first time.