关键词: 定向井, 井眼轨道, 预测, 井斜控制, 计算机程序

Abstract: Predicting the inclination and azimuth is a key issue of the bit trajectory quantitatively controlling in directional drilling.A new model of predicting and controlling the bit trajectory,named as Force-Displacenlent.Model,is presented in this paper.A mathmatical model for side cutting is established in terms of a product of powers of several related parameters,including side force on the bit,pene.traticam rate,penetration interval,bit r.P.m and rock strenghth index,etc.A set of basic equations for predicting the changes of inelinatiom azimuth build-up rate and walk rate are derived.Futhermore,a prediction and control system is formed.A prediction program with self-correcting,feedback and tracking ability is studied.The DTCPS,a directional drilling software package for predicting and controlling the bit trajecti}ry,is developed for an IBM-PC computer.Examples of field prediction of inclination and azimuth in directional drilling are 9iven in this paper.They indicate good agteement between theotetical predietion curves and the measured data.