Pressure Water Jet Theory And Application Of Basic Research

With the utilizing of the high pressure water jetting in the petroleum engineering, ultra-high pressure water jet attracts more and more interests. It is a new kind of technology designed for cleaning and cutting developed in recent twenty years. Study on features of ultra- high pressure water jetting and cutting rock is a challenging and pioneering work. This dissertation presents the systematic theoretical analysis, numerical simulations and experimental studies on the fluid flow and dynamics of ultra-high pressure jetting and on the mechanisms and features of hydraulic, and describes the development and the laboratory and field experiments of erosion rock with ultra-high pressure water jet, mechanical parameters.Numerical simulation of the ultra-high pressure immersion jetting the characteristic of a number of jet no2zles and the flowing field in drilling bottom-hole is made using large-eddy method, the standard k - e turbulence model and the SIMPLE procedure. The velocity ranges from 200m/s to 450m/s. the results show that the characteristic flowing of ultra-high jet is obviously different from that normal pressure, the patent core length is 8 to 10 times the diameter of nozzle. But the constitution of both flowing fields similarity has five sections: free jetting section, impinging section, radial flowing section, cross-flowing section and vortex section. The results also indicate that is powerful removing cuttings by using inclined nozzleExperiments were conducted on ordinary cone-shape nozzle rock cutting. The results indicate: the optimum rock cutting standoff should beyond the length of patent core, which usually is 7-12 times of nozzle diameter; the optimum standoff was influenced by nozzle inlet angle and inner duct cylinder length and the nozzle outlet and impinging time have no influence on it; two assembly of nozzle shape parameters can obtain optimum impinging effect: the first assembly is inlet angle is 60° with the cylinder length is two times of nozzle diameter; the second assembly is inlet angle is 13°13' with a cylinder length of 5 times of nozzle diameter.On the basis of analysis on hydraulic rock cutting theory and the hydraulic and machinery combination rock cutting theory, a new kind of bit simulator was manufactured and series of experiments on the effect of pressure and swirling velocity were conducted. The experiments results prove that under the same operating condition, by adopting ultra-high pressure can achieve 2-3.6 times higher cutting efficiency than employing ordinary bit.An innovative technology—ultra high pressure water jet perforating through cement and MTC blocked tubing technology was presented and professional equipments and facilities were designed and manufactured. The pilot field experiments both on Gudong oil production mine andon the Second Drilling Company of Shengli oil field were successful. Till now, using this technology, 68000m blocked tubing has been penetrated, the average penetrating speed is 38m/h; and 4500m drilling pipes were penetrated through, the average speed is 28.5m/h. This technology provides an alternative technology on rock cutting and also expanded the application fields of high-pressure water jet.