Salvage method for broken and fallen drilling rod with steps and salvage barrel used in salvage method

Abstract

The invention discloses a salvage method for a broken and fallen drilling rod with steps and a salvage barrel used in the salvage method. The method comprises the steps that in the salvage work, clamping keys arranged on the inner wall of a barrel body are used for limiting a ball base assembly to move downwards along a big-end-down barrel inner hole, and the salvage work is completed. When the broken and fallen drilling rod with the steps needs to be released, the limit of the clamping keys on the ball base assembly is removed through an elastic rotary base, so that the ball base assembly moves downwards along the big-end-down barrel inner hole to complete an expansion action to release the broken and fallen drilling rod with the steps. According to the salvage method for the broken and fallen drilling rod with the steps, an existing method that an existing three-ball salvage barrel has to release the broken and fallen drilling rod with the steps in shearing pin shearing or ball casting and pressing and other modes is changed, the purpose of salvage and releasing can be achieved only through simple downward placing and upward lifting, and operation is easy. The extension strength of the structure is the largest extension strength of the barrel body, and is much larger than that of an original shearing pin, the probability that new accidents occur in the salvage process is reduced, and the performance is reliable. The whole salvage process is simpler, smoother and reliable, and saves time and money.

Description

technical field [0001] The invention relates to a fishing method for falling fish with steps and an overshot used, and belongs to the technical field of drilling and fishing tools. Background technique [0002] With the continuous development of oil and natural gas extraction technology, the drilling depth continues to deepen, which makes downhole accidents more frequent and complicated. Casing fracture accidents are relatively common during the cementing process. Downhole accidents have a great impact on drilling, cementing, and workover work, and the damage is also serious. Oil and gas wells are scrapped, so casing fishing tools are necessary tools for every well. [0003] The three-ball overshot is a more commonly used fishing tool at present. The three-ball overshot includes a cylinder body. The shear pin is riveted with the barrel, the ball seat is provided with an inclined hole, and a steel ball and a spring are arranged in the inclined hole, the lower hole diameter ...

AI Technical Summary

Problems solved by technology

[0005]1. After the overshot is used, the shear pin has been deformed or cut off, and it must be replaced with a new shear pin before it can be used again: because the diameter of the shear pin is cut according to regulations The force design is good and it is connected with the outer cylinder and the ball seat with an interference fit, so the shear pin cannot be reinstalled in the original hole for use, and the hole must be re-drilled for renewal. Most drilling crews have no processing equipment on site and can only be transported back for maintenance. base, adding many unnecessary shipping and maintenance costs

[0006]2. When a salvage is unsuccessful, the fishing can only be lifted up and cut off the shear pin to exit the salvage operation, and other fishing tools are lowered to salvage, which not only increases the lifting The number of drills is wasted, time and cost are wasted, and it increases the difficulty of salvage and the chance of new accidents

[0007]3. The existing three-ball overshot cannot be used with the jar, because the shear pin cannot withstand the huge impact force of the jar, so it can only be used for salvage Coupled casing that is not seized

[0008]4. Unstable performance: because the shearing tonnage of the shear pin is affected by material, heat treatment, roughness, fit tolerance, force, etc., it is often difficult to meet the design requirements

[0009]5. The design of the shearing pin is difficult: the design of the shearing pin is too large and the fish cannot be salvaged. The fish has not been picked up and the clipping pin has been cut

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