Oil casing chemical repair method

Abstract

The invention relates to an oil casing chemical repair method. According to the technical scheme, the outer wall of a central tube is fixedly connected with a reaction subsidiary cylinder sleeve, wherein an inner cavity of the reaction subsidiary cylinder sleeve is provided with an aluminothermic reaction agent, the outer wall of the reaction subsidiary cylinder sleeve is provided with a pluralityof inclined holes, and the inclined holes are blocked by tin plugs; an inner cavity of the central tube is provided with an ignition fixing sleeve, an igniter, an ignition locking ring, a flammable ball seat, a flammable sealing sleeve and a screwed plug body in sequence from bottom to top, the ignition is achieved through the igniter pressed down by the ignition locking ring, the flammable ballseat is ignited, then the flammable sealing sleeve is burnt, and the burning of the flammable ball seat achieves the high-temperature heating of the aluminothermic reaction agent in the reaction subsidiary cylinder sleeve to trigger the aluminothermic reaction. The oil casing chemical repair method has the advantages that the generated melted iron and aluminium oxide enter into an inner cavity between the central tube and an oil-well casing and fill a to-be-repaired segment to achieve the reparation of the casing; a steel ball, a lighter and the like are adopted for ignition, the working procedures are reduced, and the construction cost is reduced.

Description

technical field [0001] The invention relates to a method for repairing oil pipes, in particular to a chemical method for repairing oil casings. Background technique [0002] During the exploitation of oil and gas fields, due to complex geological conditions, such as inclined wells, horizontal wells, etc., oil well casing damage often occurs. Oil well casing damage will cause the following hazards to oilfield development: 1. The production string cannot be run into the well normally; 2. When the damaged part of the casing is in the water layer or sand layer, the oil well will produce a large amount of water or sand; 3. The oil well will increase production The measures cannot be carried out; 4. It is easy to cause blowout outside the casing; 5. It causes the oil well to be scrapped. [0003] There are several methods for repairing casing ruptures in oil wells with seams or holes: 1. Squeeze the slurry: When the pressure of the oil layer is not high and the rupture and leakag...

AI Technical Summary

Problems solved by technology

The advantage of this method is to ensure the consistency of the inner diameter of the casing, and the downhole tools can pass through smoothly in future operations; the disadvantage is that the casing thread of the downhole buckle is not as tight as that on the wellhead, and the replacement of casing More expensive and more difficult to operate

[0004] Among them, the problems of the subsidy repair method are: when sand control is required, sand control pipe strings need to be run in; Fracturing pipe string; since the inner diameter of the steel pipe is smaller than the inner diameter of the casing, the diameter and specification of the running tool need to be reduced, resulting in a smaller amount of injected liquid, which affects the effects of sand control, acidizing and fracturing. In addition, the steel pipe Form a boss shape on the inner wall of the casing, so that the running string is prone to jamming

[0005] The problem with the cement-squeezing method is that when acidification is required on site, because the cement is alkaline, the acid will react with the cement, which will cause the repaired leaks to leak out again.

But the problem that it exists is: the triggering of the thermite reaction is by putting into the reaction inducing pipe string, and the bottom of the reaction inducing pipe string is provided with an electric heating pipe, which is connected to the electric heating pipe at the wellhead through a cable to the aluminum alloy in the inner chamber of the refractory protective sleeve. The thermal reaction raw materials are heated, and the construction process is relatively troublesome

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