hole table
4.A series of tech niques such as technique of deviation prevention and verticality keeping of the vertical bore hole segment, technique of control wellbore trajectory in the inclined portion with power tool or rotary table, technique of control of trajectory in the horizontal section with rotary table combined with DTL guide tool and PDC bit, technique of wellbore trajectory prediction with computer, technique of drilling fluid and technique of well completion were recommended with emphasis in the paper.

