Guided locking mechanism for casing drive heads

Abstract

The invention discloses a guiding and locking mechanism suitable for a casing pipe driving head. The guiding and locking mechanism comprises a center shaft and a clamping tile, wherein the center shaft is sleeved with the clamping tile. The center shaft is used for lifting, dropping and rotating a casing pipe through matching of the clamping tile and the casing pipe. By adopting the clamping tile, due to a key groove of the clamping tile and a gap, a tool can be set for driving the casing pipe to rotate or a driving mechanism can be taken out according to needs, locking or unlocking between the tool or the driving mechanism and the casing pipe can be changed, and the mode of drilling through the casing pipe can be implemented conveniently. Clamping teeth have good adhesive force, can achieve locking with the underground casing pipe wall effectively and can be attached to the casing pipe wall after being inserted into the casing pipe, and therefore mutual swing between the casing pipe and the casing pipe driving mechanism can be reduced, the clamping teeth can be attached to the casing pipe inner wall closely when being connected with the casing pipe completely, and the effect of preventing the casing pipe from dropping can be achieved.

Description

technical field [0001] The invention relates to a guiding and locking mechanism suitable for a casing driving head, which is used for oil and gas drilling with casing, and belongs to the technical field of design and manufacture of drilling equipment. Background technique [0002] In the process of conventional oil and gas drilling, due to the geological characteristics of the formations in various places, downhole complex situations such as borehole diameter shrinkage, well wall collapse, keyway and lost circulation caused by drilling tools in drilling often occur. In this case, after the completion of drilling When implementing casing running and cementing rotation, some wells will encounter resistance and jamming, and some even have problems such as the casing cannot be lowered to the predetermined depth. When these situations occur, the construction will not meet the requirements of engineering design, and some There will also be safety accidents in the casing running pr...

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Problems solved by technology

But this type of technology also has the following disadvantages: one, the CN200320127812.X patent must open the mud pump in the working state to transport the mud downward through the tube cavity in the center of the main shaft as the power to push the piston down, and the whole device does not have a locking mechanism. This method makes the drive head The working condition of the mud pump is directly restricted by the mud pump. If the pump pressure of the mud pump is unstable, it will easily cause work failure, and it is necessary to control the pump pressure well.

2. The CN200320127812.X patent is a method of using a return spring to separate the slip teeth from the casing. This method has the problem of return spring fatigue and incomplete reset when the strength is reduced; the slope contact area between the piston and the slip may also be due to The situation where the pump pressure is too high to cause mutual adhesion and cannot be separated

3. The expansion and reset control of slips in CN200320127963.5 patent is controlled by a large nut drive device. Although this method can lock and control the slips, the operation is cumbersome; the multi-slope structure of the sliding key has no guiding device, resulting in slips In the process of expansion and reset, there is a phenomenon that it cannot be centered, jammed or locked firmly

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