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介绍了在高温高压的井眼条件下,温度和压力对钻井液当量循环密度的影响以及由此对井底压力影响的研究结果。高温会使井眼中的流体发生膨胀,而在深井中的高压则会压缩流体。如果没有考虑到这两种相反作用的影响,就会在计算井底压力时出现较大误差。温度和压力还会影响钻井液的流变性能。开发出一个称为DDSimulator的模拟程序,用于模拟循环条件下的井眼。用宾汉塑性模型来表征所研究的钻井液的流变特性,其流变参数与温度和压力呈函数关系。在DDSimulator模拟程序中使用了Crank-Nicolson数值离散图来绘制井眼温度分布曲线。模拟结果显示,地温梯度越高,井底压力越低;钻杆入口温度对井底温度和压力无显著影响;循环速度越高,井底温度越低、井底压力越高。
The effect of temperature and pressure on the equivalent circulating density of drilling fluid and the research results of the influence on downhole pressure under high temperature and high pressure in borehole conditions are introduced. High temperatures swell the fluid in the wellbore, while high pressures in deep wells compress the fluid. If you do not consider the impact of these two opposite effects, there will be greater error in the calculation of bottom pressure. Temperature and pressure can also affect the rheology of drilling fluids. A simulation program called DDSimulator was developed for simulating boreholes under cyclic conditions. The Bingham plastic model is used to characterize the rheological properties of the drilling fluid studied, and the rheological parameters are functionally related to temperature and pressure. Crank-Nicolson numerical discretization maps were used in the DDSimulator simulator to plot borehole temperature profiles. The simulation results show that the higher the geothermal gradient, the lower the bottomhole pressure. The inlet temperature of drill pipe has no significant effect on bottomhole temperature and pressure. The higher the circulation rate is, the lower the bottomhole temperature is, and the higher the bottom hole pressure is.