THE CALCULATION OF THE FINAL AZIMUTH(AHT)IN THE TURN OF THREE DIMENSION DIRECTIONAL WELL DESIGN
Huang Kuangdao;Li Changzhu;Sun Haiwang Daqing petroleum Institute Training Department Development Department
The determination of AHT value mathematical formula is one of the mo-st important problems during the design of three dimensional software packagfor directionally drilled well.This paper studies the changing rule of final azimuth AHT under het AllAzimuthal Twisting condition of directionally drilled well in depth. It isfound that the function of AHT vs AHO is not continuuos, and the resultingclockwise, counterclockwise turning rules satisfy the optimization designof directionally drilled wellbore trajectory. Based on the above ideas, twotypes of AHT calculation methods have been presented using "Analytic" and"Domain" or "Value Domain" methods. So now, for any given values of AHO,AHS, the three dimensional design of dieretionally drilled well can be rel-ized by the software package. The authors have got the correct results provedby using different length of steps through 360 degree scale.