Development and Field Application of High Efficiency Drag and Torsion Reducing Tool

Due to high angle wells and extended reach wells have significant torque and abrasion of casing during drilling in the Jidong Oilfield,a high efficiency friction and torsion reducing tool has been designed based on the investigations of drag and torsion reducing tools around the world,which composed of rubber sleeve,low-resistance shaft sleeve with abrasion-proof ceramic and detachable shaft,and determined the technical parameters that related to tensile and torsion strength of the principal shaft based on the 3D forces calculation model of drill strings in wellbore,combined with the tensile,torsional strength of drill pipe and maximum continuous working torque of top-drive rig. At the same time,installation locations and quantities of the innovative drag and torsion reducing tools have been calculated in accordance with well trajectory,capacities of drilling equipment and field operation conditions. Lab test results showed that the principal shaft had enough tensile and torsional strength for drilling operation. The high efficiency drag and torsion reducing tools have been tested in five high angle wells that have horizontal displacement over 2 000.00 m in the Jidong Oilfield. Test results indicated that the torque was lowered by 15% than that of predicted in average during drilling,and reduced the abrasion of casing by drilling string,resulting in satisfactory application performance. The high efficiency tool can provide a new means of lowering drag and torque in drilling high angle wells and extended reach wells and protect the casing string.