运用灰色关联分析确定钻井液的流变模式

Applying Grey Relational Analysis to Selecting the Rheologic Model For Drilling Fluids

正确选择非牛顿流体的钻井液的流变模式,对优选钻井过程中的钻井水力参数,精确计算钻杆、环空的循环压降以及钻井液的携带能力都是十分重要的。在5种流行的钻井液流变模式中,哪种流变模式与所描述的钻井液相关性最好,是运用通常的作田法、列表法和相关系数法都不能很好解决的问题。本文运用灰色系枕理论的关联分析方法,定量计算每一种流变模式的计算值与实测值的关联度,通过关联度值的大小顺序,可以确定相关性最好的流变模式,文中详细地描述了现有的5种流变模式和灰色关联分析的数学方法,并运用该方法对某井钻井液进行实例计算,得到了满意的结果。

It is very important to select correctly the theologic model for non-Newtonian drilling fluids in optimizing the drilling hydraulic parameters and calculating the flowing pressure drop in drittpipe or in annulus and cutting-carrying capacity of drilling fluids. It is difficult to determine which of the five prevailing rheologic models is best correlated with the drilling fluids described by methods of tabulation, plotting and correlation coefficient. In this paper, a grey relational analysis of the grey system theory is applied to calculating the relational grade of the calculated and measured values from various rheologic models. The best rheologic model can be found by the values of grey relational grade. The five theologic models and mathematical model of the grey relational analysis are described in detail. Calculations of practical data of the drilling fluid used in a well are made and satisfactory resuits are obtained.