A method of using a desealable water-swellable packer

Abstract

The invention relates to a method for using a deblocking water-swellable packer. The technical scheme of the method is that an upper center pipe and a lower center pipe are movably connected through adeblocking liner pipe, the upper center pipe is fixed to the middle of the deblocking liner pipe through an upper deblocking shear pin, the lower center pipe is fixed through a lower deblocking shearpin, an upper blocking ring is fixed to the outer wall of the middle of the upper center pipe, the outer end of the upper center pipe is provided with an upper connector, a lower blocking ring is fixed to the outer wall of the middle of the lower center pipe, and the outer end of the lower center pipe is provided with a lower connector. Water-swellable rubber is processed on the outer wall. The method for using the deblocking water-swellable packer has the advantages that by design of the deblocking structure, contraction of the water-swellable rubber can be achieved, deblocking is achieved,the conditions of failure in pulling caused by high resistance of the water-swellable rubber during well repair can be avoided, a huge collapsing force on a stratum caused by a suction effect of the packer when a tensile force is reinforced in a forced mode for pulling is also avoided, and the problems of high cost and long operation cycle caused by milling operation through milling shoes are alsosolved.

Description

technical field [0001] The invention relates to an oil well operation tool and method, in particular to a method for using a desealable 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-l...

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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