A Method for Friction Reduction and Power Drill Tool Face Adjustment in Complex Structure Wells

Abstract

The invention belongs to the technical field of drilling, and relates to a method for reducing friction in wells with a complex structure and adjusting the tool face of a power drilling tool. Torque acts as a reciprocating rotary motion, and the middle drill string undergoes axial vibration / creep under the action of the axial vibration drag reduction tool, which converts the static friction between the drill string and the well wall into dynamic friction, thereby reducing the axial feeding of the drill string Resistance, the axial vibration at the lower drill bit will cause the WOB to fluctuate, which will cause the rock-breaking torque and counter torque to fluctuate. The effect of friction reduction; it is easy to operate and scientific in principle, which can save the time of adjusting the tool face angle of the power drilling tool, and continue drilling while adjusting the tool face, improving the performance of complex structure wells, especially complex structure wells with long horizontal displacement. High drilling efficiency and lower drilling cost.

Description

Technical field: [0001] The invention belongs to the technical field of drilling, and relates to a friction reduction and power drilling tool face adjustment process in the sliding drilling process of complex structure wells, in particular to a friction reduction and power drilling tool face adjustment method for complex structure wells. Background technique: [0002] Compared with ordinary vertical wells, wells with complex structures such as horizontal wells have a larger reservoir control area, which can greatly increase the production of a single well and reduce the cost per ton of oil. It has become the most important means of developing complex oil and gas reservoirs and offshore oil and gas resources. At present, the traditional directional drilling method of "dynamic drilling tool + MWD" is still widely used in the drilling of complex structure wells. In the process of directional drilling, there is a lot of friction between the drill string and the well wall because ...

AI Technical Summary

Problems solved by technology

Although the above method can achieve a certain effect of reducing friction, it also has defects, which are mainly reflected in two aspects. One is to avoid the ground torsion effect from affecting the stability of the tool face angle of the power drilling tool. In the buffer zone, the drill string does not rotate, thereby reducing the friction reduction effect; second, when the horizontal extension distance of the well is long, only when the ground torsion depth is relatively large in a torsional pendulum cycle In order to have an obvious anti-friction effect; the patent U.S.Pat No. 7,588,100 has announced a method for reducing friction in complex structure wells with variable speed drilling. The working principle of this method is to control the rotation speed of the ground drill string. When the face angle is within the range of the directional drilling tool face angle, slowly rotate the drill string, and when it is not within the range, quickly rotate the drill string, so that the time when the power drill tool face is within the range of the directional drilling tool face angle accounts for the absolute drilling time. most of the time

Due to the change of downhole friction, the torsional deformation of the drill string changes, so that the corresponding relationship between surface torsion and downhole tool face torsion cannot be accurately judged, so this method is difficult to implement

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