控压钻井中节流阀开度与节流压力的关系研究

Research on the Relation Between Throttle Valve Opening and Throttle Pressure in Pressure Control Drilling

采用试验的方法对节流阀开度大小和节流压力关系进行研究须选取大量参数重复试验,工作量大、耗费人力物力多。为此,建立了锥形节流阀的Fluent数值模拟模型,模拟计算了不同黏度、密度和开度等参数组合下的节流压力,分析了不同参数组合下节流压力的变化规律,建立了包含密度、排量和开度的3参数节流压力函数模型。基于计算压力和实测压力曲线形状相似的事实,提出了基于数值模拟和试验数据平移修正的节流阀开度与节流压力函数关系确立的方法,并用该方法确定了1组待定参数下的节流阀开度与节流压力的函数关系模型。节流阀开度与节流压力关系验证表明,实测压力与计算压力曲线形状大致相同,存在曲线平移的基础,最大相对误差为9%。上述数值模拟和试验数据平移修正的方法,可以用于其他类型节流阀开度与节流压力关系的建立。

Research on the relation between throttle valve opening and throttle pressure with the experimental method must select a large number of parameters to conduct repeated tests, which requires heavy workload and needs many material resources and much manpower. Therefore, the Fluent numerical simulation model for cone-shaped throttle valve was established to simulate and calculate the throttle pressure under different parametric combinations of viscosity, density and opening. The three-parameter throttle pressure function model which includes density, displacement and opening was established. The method to determine the functional relationship between throttle valve opening and throttle pressure on the basis of numerical simulation and translational correction of test data was pro- posed. The method was used to determine the model for the functional relationship between throttle valve opening and throttle pressure under a group of parameters to be determined. The verification of the relationship shows that the curve forms of actually measured pres-sure and calculated pressure are roughly similar. And the maximum relative error is 9%.