Hot rolling repairing method for corroded eccentric-wear waste oil pipe

Abstract

The invention provides a hot rolling repairing method for corroded eccentric-wear waste oil pipes. According to the method, the screened waste oil pipes are taken as raw material pipes, a natural gasheating furnace is used for heating the waste oil pipes with the eccentric wear depth which is larger than 10% of the standard wall thickness and smaller than or equal to 40% of the standard wall thickness to 1250 DEG C, then two sets of three-roller beveling type hot rolling units are adopted for continuous hot rolling to perform uniform diameter expanding wall reducing treatment and uniform diameter reducing wall increasing treatment on the oil pipes, and finally cooling and precision forging sizing treatment are conducted. According to the method, the adopted natural gas heating furnace ensures uniform heating of the whole oil pipes, the cracking phenomenon caused by uneven heating in a traditional hot rolling repairing process is avoided, the repaired oil pipes meet related standard requirements, and remarkable economic benefits are achieved.

Description

Technical field [0001] The invention belongs to the technical field of repairing waste oil pipes for oil and gas exploitation, and particularly relates to a hot rolling repair method for corroded and partially worn waste oil pipes. Background technique [0002] Tubing accounts for more than 10% of the total steel consumption in the petroleum industry. PetroChina’s main domestic oil fields have nearly 440 million meters of downhole tubing, about 4 million tons; Sinopec’s major domestic oil fields have about 220 million meters of downhole tubing, about 2 million tons. During the use of the oil pipe, the inner wall of the pipe and the thread of the joint will be scrapped due to eccentric wear, corrosion and other reasons, which will affect the safe production of the oil field. Calculated on the basis of an average life span of 10 years, the number of used oil pipes in domestic oil fields alone can reach more than 700,000 tons per year. [0003] In recent years, most of the domestic o...

AI Technical Summary

Problems solved by technology

Traditional repair methods mostly use medium-frequency induction heaters to locally heat the oil pipe and then perform hot-rolled uniform wall repair. The heating coil of this method usually does not exceed 1 meter. Larger, and the temperature distribution in the heated area of ​​the oil pipe is uneven along the axial direction. The oil pipe with a slightly severe degree of corrosion and partial wear is prone to burn cracks and bursts after hot rolling, which cannot meet the repair requirements of moderately corroded and partial wear waste oil pipes.

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