Drag-reducing and wear-resisting drill string protector

Abstract

The invention relates to a drag-reducing and wear-resisting drill string protector used in the fields of petroleum drilling and the like. The technical scheme is that the drag-reducing and wear-resisting drill string protector comprises a drill string, shaft sleeves, bolts, a sliding sleeve, clamping bolts and wear-resisting sleeves, wherein the shaft sleeves are arranged up and down, and the shaft sleeve at the lower part is connected with and clamps the drill string through the locking bolt; the sliding sleeve is fixed on the shaft sleeves through the clamping bolts; and the wear-resisting sleeves are connected through the locking bolts and arranged on the outer circumference of the sliding sleeve; and finally, the shaft sleeve at the upper part screws up the locking bolts to complete assembly. When the drill string rotates to deviate from the center, the wear-resisting sleeve with larger size is firstly contacted with a casing pipe, as the wear-resisting sleeve has low friction coefficient and good self-lubricating performance and can rotate freely relative to the drill string, and simultaneously the wear-resisting sleeve also has excellent wear resistance, the wear-resisting sleeve and the sliding sleeve are contacted and move through a PDC bearing during working, and the drag and the friction torque can be effectively reduced. In conclusion, the drag-reducing and wear-resisting drill string protector is convenient and fast to assemble and disassemble, the friction wear between the drill string and the casing pipe can be avoided, the energy loss during the torque transmission process during drilling can be reduced, and the service life of the drill string can be greatly prolonged.

Description

technical field [0001] The invention relates to a downhole tool for oil and gas drilling, in particular to a drag reducing and antiwear drill string protector used in drilling operations with complex structures such as directional wells, horizontal wells, highly deviated wells and extended displacement wells. Background technique [0002] In the process of oil drilling, the drilling workload of deep wells, ultra-deep wells and extended-reach wells is increasing day by day. When drilling deep wells, the drill string needs to have long-term contact and friction with the downhole casing. As the well depth increases or the wellbore Due to the complex trajectory and other reasons, the friction and wear between the drill string and the casing is too large, the casing is severely worn or even worn out, and cannot withstand pressure, which brings many difficulties to subsequent construction operations, making it difficult or even impossible to complete the well in the later stage. S...

AI Technical Summary

Problems solved by technology

[0002] In the process of oil drilling, the drilling workload of deep wells, ultra-deep wells and extended-reach wells is increasing day by day. When drilling deep wells, the drill string needs to have long-term contact and friction with the downhole casing. As the well depth increases or the wellbore Due to the complex trajectory and other reasons, the friction and wear between the drill string and the casing is too large, the casing is severely worn or even worn out, and cannot withstand pressure, which brings many difficulties to subsequent construction operations, making it difficult or even impossible to complete the well in the later stage. Serious consequences of well completion; not only that, if the accumulated torque of the downhole drill string increases, it will easily cause drilling tool breakage accidents, increasing drilling costs and risks; the performance of the casing, such as the collapse resistance and internal pressure resistance, will eventually affect the Drillstring and Casing Safety and Wellbore Life Seriously Compromised

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