Fishing device and method of downhole HDPE (High-Density Polyethylene) well pipe of brine well

Abstract

The invention discloses a fishing device and method of a downhole HDPE (High-Density Polyethylene) well pipe of a brine well. The fishing device is formed by combining a drill rod and a fisher, wherein the fisher is movably connected with the drill rod, the two ends of the fisher can be clamped or penetrated into the inner wall of the fished well pipe, and a connecting fulcrum is arranged at the eccentric position of a plate of the fisher; a wedge-shaped guide head is arranged at the bottom end of the drill rod. The fishing method is described as follows: the drilling rod is connected with a drilling machine, the drilling machine is started, and the fishing device is placed into the well pipe by virtue of guiding of the wedge-shaped guide head, and the fisher contacts or rubs the wall of the well to rotate to a certain angle when the fishing device is placed into the well pipe, so that the fishing device can be placed into the well pipe in a way that the fisher closely clings to the well pipe; the drilling rod is lifted upwards, and fishing pulling force is transmitted to the fisher, so that the fished well pipe is clamped or jammed by the fisher; the drilling rod is lifted upwards continuously, the fished well pipe and the fisher are lifted at the same time, the action is continued, and the fished well pipe is fished out of the brine well finally. The fishing device has high success rate of fishing and can be smoothly placed into the well, and the fished well pipe can be successfully clamped or jammed by the fisher of the fishing device, so that the well pipe is fished smoothly.

Description

technical field [0001] The invention relates to a device and method for fishing an HDPE well pipe in a brine well, which is mainly used for salvaging an underground outlet pipe of a brine well (well pipe material: HDPE polyethylene). Background technique [0002] The salvage of downhole equipment has always been an industrial problem. The underground space of the brine well is narrow, and it is difficult for large equipment to enter the well for operation. During the construction of brine wells in the Great Salt Flat of Lenghu Lake in Qinghai, it is necessary to salvage 40m to 100m long Φ160HDPE polyethylene well pipes from the underground. [0003] In the downhole, the well pipe is firmly stuck at the bottom of the well due to the salt formation of brine. If the lifting force is small, it is difficult to release the jam. see Figure 7 , the downhole salt block 6 locks the well pipe to indicate. [0004] If an excavator or a crane are used to forcefully pull out the well ...

AI Technical Summary

Problems solved by technology

If you want to use an excavator or a crane to pull it out forcefully, because there is no well pipe exposed above the ground, there is no point of focus, so it cannot be operated

The well where the well pipe was pulled out is still spraying water, causing great trouble to the project

[0005] At present, there is no ready-made salvage equipment available in China

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