deviation hole
2.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.
5.In order to develop the low production and low permeability oilfields, four slim hole cluster wells were drilled on one platform in Jinn Oilfield, with the diameters of 152. 4mm each, well depths of 1729. 47- 1855. 53m, maximum deviation angle of 42°, and maximum lateral displacement of 514m. . Its cost was reduced by 19. 1 % in comparison with the conventional wellbore.
