Method and device for salvaging fishes of different diameters without replacing slips

Abstract

The invention discloses a method and a device for salvaging fishes of different diameters without replacing slips. The method adopts a group of movable slips evenly distributed along the circumference to salvage fishes; the movable slips evenly distributed along the circumference can synchronously, inwardly and radially move to reduce the salvage caliber of the slips or synchronously, outwardly and radially move to expand the salvage caliber of the slips in order to adapt to the requirements of fishes of different diameters. The invention can salvage all fishes of different diameters within a certain diameter range without replacing the slips, and broaden the applicable range of the slips. The structure of the device is simple, salvage is reliable, and the device can release fishes in a well. The device is particularly suitable for long-time downhole use and the salvage of pipe strings in unknown surface corrosion conditions. The drilling efficiency is greatly improved and the drilling cost is greatly reduced.

Description

technical field [0001] The invention relates to a method and a device for fishing fallen fish with different diameters without replacing slips, and belongs to the technical field of downhole tools. Background technique [0002] In recent years, with the continuous development of oil and natural gas extraction technology, the drilling depth has continued to deepen, which has resulted in more frequent and complicated drilling accidents. In the drilling and exploitation of oil and natural gas, the retractable slip overshot is widely used at present. [0003] The slips trap the fish with a smooth outer diameter when fishing, and then apply a lifting force. The serrated threads on the inner surface of the slips bite into the fish deeply, and they can also be turned forward to loosen the fish when the fishing is abandoned. But because of the reason of the structural principle of the reversible slip overshot of the prior art, a slip of a specification can only salvage the fallen f...

AI Technical Summary

Problems solved by technology

The measurement of the outer diameter of the fallen fish by printing requires the fish to be almost motionless and centered in the accident well, but this is rarely the case, and the measurement by printing is not accurate and most of them are unsuccessful

[0006]3. According to the downhole records and estimated drill pipe wear, the actual outer diameter of the fallen fish is predicted. Each drill pipe or drill collar is different due to the use time and rock formation. The empirical value of outer diameter wear often has great discrepancy, and the slips in the well cannot catch the fish, resulting in secondary or multiple fishing operations

[0007]4. In production well workover operations, it is impossible to salvage the strings that have been used downhole for a long time and whose surface corrosion is unknown

[0008]The occurrence of each of the above situations will seriously affect the drilling efficiency and increase the drilling cost

Therefore the existing way of salvaging fish is still not ideal enough to meet the needs of oil and natural gas production.

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