Diameter-retractable casing screw head

Abstract

The invention discloses a diameter-retractable casing screw head. The diameter-retractable casing screw head is characterized in that the diameter-retractable casing screw head comprises a curved screw head; the curved screw head is divided into a plurality of unit blocks through a plurality of wedge-shaped grooves, an outer threaded structure is installed on the outer side of a curved screw head body of each unit block, and a ball is installed between each outer threaded structure and the corresponding curved screw head body; the outer side face of each curved screw head body and the inner surface of the corresponding outer threaded structure are the same shrunk-type curved surfaces, the outer surface of each outer threaded structure is a circular curved surface and is provided with a thread, and grooves are formed in the outer side face of each curved screw head body and the inner surface of the corresponding outer threaded structure correspondingly; and the balls are installed in the grooves. During casing, the diameter-retractable casing screw head can transfer torque and pressure and convey cooling water; while after a casing pipe follows to a preset position, the casing pipe does not need to be lifted, the screw head can be directly dismounted in a hole, and then a new casing pipe is additionally arranged directly; and casing efficiency is improved, abrasion of a drill bit and the casing pipe is greatly reduced, and drilling pipes can be used for a longer time.

Description

technical field [0001] The invention relates to a screw head for a heel tube, in particular to a screw head for a heel tube with an expandable diameter. Background technique [0002] Drilling construction is currently the most direct way to understand geological conditions and hydrological conditions in engineering surveys. During drilling construction, due to geological conditions, cross-hole phenomenon often occurs in drilling. At present, the domestic treatment of borehole collapse can use drilling fluid to protect the wall or drill with the pipe. However, for some shallow hole drilling of 100m to 300m, the use of specially configured drilling fluid during construction will greatly increase construction costs and affect engineering benefits. Therefore, in the construction process of shallow holes, the main measures for retaining wall plugging are to use the method of follow-up pipes, and use casings to isolate the collapsed hole sections. The screw head used in pipe con...

AI Technical Summary

Problems solved by technology

However, the drilling section where casing needs to be run often collapses. During the process of lifting the casing, the probe stone and the collapsed surface will collapse and close together, which will cause the casing to be lowered to the predetermined depth.

It is necessary to follow the pipe again, which affects the efficiency of the pipe follow-up, and also causes great wear and tear on the pipe-following drill bit and casing

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