Multi-stage deblocking type water-swelling packer and method

Abstract

The invention relates to a multi-stage deblocking type water-swelling packer and a method. According to the technical scheme, the multi-stage deblocking type water-swelling packer comprises three sections of central pipes, a set of water-swelling rubber and two sets of deblocking devices; the water-swelling rubber is machined at the outsides of the three sections of the central pipes and the two sets of the deblocking devices, the first set of the deblocking devices is disposed between the first and second sections of the central pipes, and the second set of the deblocking devices is disposedbetween the second and third sections of the central pipes; and the outer walls of the first, second and third sections of the central pipes, the first and second sets of the deblocking devices are machined with the water-swelling rubber. The multi-stage deblocking type water-swelling packer and the method have the beneficial effects that a multi-stage deblocking structure is designed, the contraction of longer water-swelling rubber can be achieved and the deblocking can be realized, the situation in which the water-swelling rubber is too large in resistance to be moved by pulling during the well repair can be avoided, and the drawing by forcedly enlarging the tensile force can be avoided; and the problems of high cost caused by the milling operation through grinding shoes and long workingcycle can be avoided.

Description

technical field [0001] The invention relates to an oil well operation tool and method, in particular to a multi-stage unsealable water-swellable packer and method. 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 mul...

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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