Downhole displacement type impact method and impact drilling tool

Abstract

The invention discloses an underground displacement type impact method and an impact drilling tool, and relates to the field of drilling tools. The impact drilling tool comprises an overflowing sleeve, a first main shaft, an impact bearing seat and a second main shaft which are all composed of annular structures and are sequentially connected from top to bottom, the impact bearing seat is sequentially connected with a vibration sleeve, a vibration starting seat and an impact head from top to bottom, the vibration sleeve is fixedly connected with the impact head through a connecting sleeve, the vibration starting seat and the impact bearing seat synchronously rotate in a spline connection mode, and the vibration starting seat generates axial up-and-down periodic displacement in the rotating process. According to the drilling tool, rock breaking is conducted in two modes of rotation energy and impact energy, well bottom pressurization of a horizontal well and an extended reach well can be achieved, and high-frequency periodic impact force and static pressure rotation are generated to jointly act to break rock.

Description

technical field [0001] The invention relates to the field of drilling tools, in particular to a downhole displacement percussion drilling tool and a percussion method for drilling deep hard formations. Background technique [0002] At present, most of the drilling methods are rock-breaking drilling in the rotary mode, that is, when working, only the shear force generated by the drill bit is used to realize the drilling work. In this way, the rotary drilling method completes the crushing of rocks, but for hard formations, if the generated torque cannot reach the level of breaking rocks, the drill bit will stop rotating instantly, but if the torque concentration reaches the level of breaking rocks, it will be suddenly stopped. If released, a much larger than usual impact load will be generated on the bit teeth, which will eventually lead to the failure of the bit. [0003] On the other hand, the only rotary drilling method used is easy to form a deflection moment on the drill...

AI Technical Summary

Problems solved by technology

In this way, the rotary drilling method completes the crushing of rocks, but for hard formations, if the generated torque cannot reach the level of breaking rocks, the drill bit will stop rotating instantly, but if the torque concentration reaches the level of breaking rocks, it will be suddenly stopped. release, a much greater than usual impact load is generated on the bit teeth, which eventually leads to the failure of the bit

[0003] On the other hand, the only rotary drilling method used is easy to form a deflection moment on the drill bit, which will cause well deviation during the drilling process, especially when drilling for hard rock and complex formations

[0004] The above situation not only caused great damage to the drilling tool, but also had a huge impact on the cost input; therefore, the improvement of the drilling tool, especially the improvement of the drilling method, has become a difficult problem for designers to overcome

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