A Shallow Casing Leakage External Reinforcing and Repairing Technology

Abstract

The invention provides a shallow casing leakage external reinforcement and repairing process that can form multiple cementing barriers outside the leakage casing, effectively guarantee the repair effect, and at the same time, the inner diameter of the casing does not change, and does not affect the implementation of various production increase and injection measures. According to the size of the surface casing and oil layer casing, select the appropriate casing milling head and casing milling barrel to implement casing milling of the oil layer casing. According to the equipment capacity, basic data of oil and water wells and other parameters, casing milling is carried out to the position where the original cementing cement returns to the high position. At this time , there is no need to propose casing milling pipe strings, and the circulating cement slurry cementing is carried out directly, the cement ring is connected back to the original cementing cement, and a multi-stage cementing barrier composed of casing milling pipes and cement sheaths is formed outside the oil layer casing, which is effective Repairing shallow casing leaks is of great significance to achieve safe operation and high-efficiency production. This process completely repairs the casing damage above the cement return height at one time, and the superficial casing leakage external reinforcement and repair technology has changed the previous repair ideas and methods.

Description

technical field [0001] The invention relates to the technical field of oil-water wells, in particular to a shallow casing leakage external reinforcement and repairing process. Background technique [0002] After more than 50 years of development, many oil wells have entered the late stage of ultra-high water-cut development. With the prolongation of production time, the condition of casing is deteriorating day by day, and shallow casing leakage occurs frequently, which seriously affects the normal production of oilfields. Conventional repair methods for shallow casing leaks have the following disadvantages during use. 1. Replace the casing for construction, and the repair effect is good. The lower casing that has not been replaced still has the risk of damage and leakage as the production time prolongs. 2. Carry out internal reinforcement of the casing, use expansion tubes or sticking plugging tubes for internal reinforcement of the casing, which can meet the needs of some ...

AI Technical Summary

Problems solved by technology

Conventional repair methods for shallow casing leaks have the following disadvantages during use. 1. Replace the casing for construction, and the repair effect is good. The lower part of the casing that has not been replaced will still have the risk of damage and leakage as the production time prolongs

2. Carry out internal reinforcement of the casing, use expansion tubes or sticking plugging tubes for internal reinforcement of the casing, which can meet the needs of some casing repairs, but after the internal reinforcement is implemented, the inner diameter of the casing will be reduced accordingly, which will affect the measures for running tools and increasing production and injection implementation

3. Cement slurry plugging is effective for deep casing leakage, but for shallow construction, especially above the cement return height, it is difficult to meet the design requirements in terms of construction materials and construction pressure, and the construction effect is poor

At the same time, if the shallow casing is corroded, the compression resistance is poor, and it is easy to cause deformation of the casing during the plugging construction, which will affect the subsequent construction of drilling plugs.

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