A drill string multi-stage damping device

Abstract

The invention discloses a multi-stage damping device for a drill stem. A drill stem connecting rod is fixedly connected with a first damping sleeve, an air mechanical type damping device is arranged between the first damping sleeve and a second damping sleeve, and an elastic damping cylinder is arranged in the second damping sleeve. The second damping sleeve is connected with a third damping sleeve, and a hydraulic spring-loaded type damping device is installed in the third damping sleeve. A spline shaft is arranged in the first damping sleeve, the second damping sleeve and the third damping sleeve, and a spline is arranged at the outer end of the spline shaft. According to the multi-stage damping device for the drill stem, by arrangement of combination of the air mechanical type damping device and the hydraulic spring-loaded type damping device and auxiliary adoption of the elastic damping cylinder and an elastic damping rod which are connected through a connecting pin, the multi-stage damping effect is achieved, the drilling requirements of a deep well or even a super deep well can be well met, the service life of the drill stem is effectively improved, and vibration of the drill stem is lowered; and in addition, a damping spring further arranged on the multi-stage damping device, and the damping effect is further improved.

Description

technical field [0001] The invention relates to a drill string multistage damping device, which belongs to the technical field of drilling equipment. Background technique [0002] The drill string is the general term for the steel pipe string above the drill bit and below the faucet. Drill string mainly includes kelly, drill pipe, drill collar and other drilling tools. In the actual drilling process of deep wells, the downhole environment is very harsh, resulting in very complicated stress on the drill string, and the drill string is always under pressure, tension, bending, torsion and other loads. Under the action of these loads, the drill string is often accompanied by an unstable vibration state during the downward drilling process. There are three main forms of drill string vibration: longitudinal vibration, lateral vibration and torsional vibration. For vertical wells, drill string fatigue damage is mainly caused by drill string longitudinal vibration. The longitudi...

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Problems solved by technology

[0004] Therefore, in order to reduce drilling costs, improve drilling efficiency and develop drilling technology, it is necessary to design a drill string damping device. The current drill string damping device generally adopts a first-level shock absorbing structure, such as a single hydraulic spring Type shock absorber and fully hydraulic shock absorber, these shock absorbers reduce the impact load of the drill string to a certain extent, however, in the deep well drilling in the range of 4500-6000m and the ultra-deep well drilling of 6000-9000m, this single The existing shock absorber has been difficult to meet the shock absorption needs, and the drill string is still prone to breakage or sticking. Therefore, it is necessary to design a new type of multi-stage shock absorber to meet the needs of deep well drilling.

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