水力喷砂射孔压力变化特征分析

Analysis of pressure variation of hydraulic sand-jet perforating

水力喷射压裂工艺具有射孔压裂连续作业、风险低、定点起裂等优点，有广阔的应用前景。为了能更好地指导水力喷射压裂现场施工，结合工艺施工原理，重点分析了喷砂射孔作业时各个阶段的施工压力变化特征，并进行了理论计算和现场验证。结果发现典型水力喷砂射孔施工曲线应为一条横向“S”形曲线。当开始喷射时，混砂液到达喷嘴之前，油管压力会下降，当混砂流过喷嘴时，压力逐步上升并稳定；到顶替液阶段时．压力继续逐步上升到峰值后然后下降．这一结论在水力喷射压裂工艺现场施工中起着重要的参考作用．为判断实际有效射孔时间以及工具是否异常等提供依据．具有一定的指导意义、

Hydraulic jet perforating fracturing process has advantages of continuous operations of perforating and fracturing, low risk, initiating fracturing at a fixed-point, etc., with broad application prospects. In order to better guide the fracturing site construction of hydraulic jet perforating, features of the construction pressure variation at all stages when sand-jet perforating operation are analyzed, combined with the construction principle of the process, and the theoretical calculations and field verification are conducted. It was found that the construction curve of typical hydraulic sand-jet perforating should be a transverse ＂S＂ -shaped curve. When the jet starts, the tubing pressure will drop before the sand liquids get to the nozzle. When the sand liquids flow through the nozzle, the pres- sure gradually increased and stabilized; when up to the replacement liquid phase, the pressure continues to rise to a peak and then gradually declines. This conclusion plays an important reference in the hydraulic jet fracturing site construction. It provides basis for judging the real effective perforating time and whether the tools are abnormal.