An oil well operation tool

Abstract

The invention relates to a petroleum underground operation tool. According to the technical scheme, an upper central pipe and a lower central pipe are movably connected through an unsealing liner pipe, the upper central pipe is fixed in the middle part of the unsealing liner pipe through an upper unsealing shear nail, the lower central pipe is fixed through a lower unsealing shear nail, an upper retaining ring is fixed on the outer wall of the middle part of the upper central pipe, an upper joint is arranged at the outer end of the upper central pipe, a lower retaining ring is fixed on the outer wall of the middle part of the lower central pipe, a lower joint is arranged at the outer end of the lower central pipe; the outer wall is processed with water-swellable rubber. The petroleum underground operation tool has the advantages that, by designing the unsealing structure, the shrinkage of the water-swellable rubber and the unsealing can be achieved, the situation that the pulling cannot be carried out due to the large resistance of the water-swellable rubber during work over can be avoided, the problem that the drawing must be carried out by forcedly increasing the pulling force isalso avoided, the great destructive force is generated to the stratum due to the pumping action of the packer, and the problems of high cost and long operation period caused by grinding and milling operation by grinding shoes can be avoided.

Description

technical field [0001] The invention relates to an oil well operation tool and method, in particular to an unsealable water-swellable packer. Background technique [0002] The packer is a special tool for downhole stratified isolation composed of steel body, packer and control part, which is used in the petroleum industry to meet the technical purpose of oil and water wells or the technical measures of oil layers. Oil production, water injection and reservoir stimulation all require corresponding types of packers. Including self-sealing, expanding, compressing and combined structures, their application fields are different. When encountering open hole wells and oil wells with damaged casings, the above four packers are used to seal through mechanical or hydraulic sealing. If the sealing effect cannot be achieved, the water-swellable packer developed in recent years can be used. At present, the existing water-swellable packers are generally used in multi-layered formations ...

AI Technical Summary

Problems solved by technology

The problem is: because there is always an oil-water mixture downhole, the packer is always in a state of expansion

However, when workover is required, the entire pipe string needs to be taken out, and the original water-swellable packer has a large resistance and cannot be pulled out because it is always in an inflated state; The suction effect of the packer is too destructive to the formation, and even the original solidification structure of the crosslinking agent, curing agent, acidifying agent and sand injected into the formation before is destroyed, seriously causing waste of the oil well. Well; Another way is to grind and mill the packer through grinding shoes, which has the problems of high cost, long operation period, and easy damage to the well wall or casing

[0004] In addition, the length of the water-swellable rubber used in the existing water-swellable packers is generally short, and sometimes a complete seal cannot be achieved. Even if the water-swellable rubber is lengthened during manufacture, the water-swellable rubber does not necessarily It will expand evenly, so it is still not completely reliable to achieve sealing; and after the water-swellable rubber is lengthened, because the existing technology cannot achieve unsealing, the workover time will be longer, and the well wall or casing may be worn. Therefore, packers with extended water-swellable rubber are rarely used in actual production

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