A jar for coiled tubing jam release

Abstract

The invention provides a jar for coiled tubing jam release and belongs to the technical field of coiled tubing drilling. The jar comprises a jar shell, a jar core shaft installed in the jar shell, a strong spring installed in the jar shell and a movable piston rod installed in the jar shell. By means of the cooperation of the jar core shaft and the strong spring, coiled tubing achieves continuous upward impact, namely coiled tubing can generate greater impact loads by the action of elastic potential energy of the strong spring and a jarring effect can be achieved at a jam point of coiled tubing; through continuous reciprocating impact for a jam point achieved via elastic potential energy generated by coiled tubing and through the jarring effect of impact loads on a jam point of coiled tubing, coiled tubing jam release work can be facilitated, the difficulty of jam release of coiled tubing is reduced, the problem that coiled tubing snaps because upward pulling force in a coiled tubing jam release process is greater than the breaking pulling force of the coiled tubing is solved and safe and efficiency jam release of coiled tubing is achieved.

Description

technical field [0001] The invention relates to the technical field of continuous oil drilling, in particular to a jar used for releasing stuck coiled tubing. Background technique [0002] In recent years, with the exploitation of oil and natural gas resources more and more fully. There are fewer and fewer oil resources that are conducive to extraction, and people are turning their attention to shale oil and gas and some oil resources that need to be turned to drilling. Due to the single drilling direction and low work efficiency of the previous rotary drilling method, it was gradually replaced by the coiled tubing drilling technology with wide applicability and high work efficiency. [0003] When the uplift force required to lift a coiled tubing exceeds 80% of its yield strength, the condition is defined as a stuck coiled tubing. The reasons for the stuck coiled tubing mainly include the following: (1) During the drilling process, the drilling fluid is continuously circul...

AI Technical Summary

Problems solved by technology

The reasons for the stuck coiled tubing mainly include the following: (1) During the drilling process, the drilling fluid is continuously circulated to cool the drilling process, but the solid particles contained in it are easy to accumulate in the holes where the coiled tubing passes. As a result, the coiled tubing string is stuck; (2) when the coiled tubing is drilled, the diameter of the wellbore is small, and when the formation is deformed, it is easy to squeeze the tubing wall and deform, resulting in a stuck situation; (3) in the wellbore When the drilling fluid falls into the drilling tool, it needs to be salvaged. If the salvage operation is improperly operated, it is easy to cause the coiled tubing string to be stuck; (4) There is a problem with the operation method during the cementing operation The resulting coiled tubing is stuck; (5) The coiled tubing is stuck due to the generation of a large amount of debris during the perforating operation

[0004] In the prior art, the injection head is usually used to unblock the coiled tubing. However, since the maximum lifting force of the injection head is generally much greater than the maximum pulling force that the coiled tubing can withstand before it breaks, once the coiled tubing is seriously stuck, injection The pulling force generated by the coil head is easy to exceed the breaking force of the tubing, which will directly break the coiled tubing

Moreover, once the coiled tubing string is broken, it will be more difficult to release the jam, and the oil well will also be unusable.

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