Three-dimensional catenary profile design method

The catenary profile can reduce the drill string drag, and making use of the nature drift rule of bit for drilling can liberate WOB and increase ROP. This paper combines the advantages of the catenary profile and azimuth drift, and systematically studies the three-dimensional catenary profile design method. This study has set up the mathematic model of the three-dimensional catenary profile, analysed the coupling relation of inclination units and azimuth units, put forward the constraint equation of the three-dimensional catenary profile design, and formed a systematical design method of three-dimensional catenary profile. Finally, it validates the correctness of theoretical models through a design example.