Set and method for repariring oil well casing by using iron based shape memory alloy

Abstract

This is a mending method used to mend the oil-well casing pipe device. The mending material is an iron-base recall alloy. This device contains: up-recall washer, down-recall washer, outer bushing pipe, and inner bushing pipe, hydraulic pressure vessel, reamer, press ring and heater. The up-recall washer and low-recall washer are composed with iron-base recall alloy, its composition is: 3-4%Si, 4-30%Mn, 0-18%Ni, 0.05-1.47%Zr, 0.05-1.47%Ti, 0.01-0.04%N, 0.05-0.8%Ti, especially demand have ZrC, TiC, So that the stipulation demand the carbon content must mate with the Zr or Ti in the alloy.

Description

technical field [0001] The invention relates to a pipeline repairing device, in particular to a device and method for repairing an oil well casing using an iron-based shape memory alloy. Background technique [0002] At present, there are many reasons for serious casing damage in oil production wells in oilfields: in-situ stress, groundwater immersion, hydrogen sulfide corrosion of crude oil, accidental mechanical damage, and the influence of alternating temperatures in thermal recovery operations, etc. Oil well casing damage can be classified into three types: dislocation, hole and crack. Casing was partially damaged and leaked, causing groundwater to flow into the well, and the oil well was filled with water and forced to stop oil production and seal the well and leave it idle. Most domestic oil wells in China are relatively deep, usually more than 1,000 meters long. A new well will cost 5 million yuan for the uphole and downhole construction. The oil wells in western Chi...

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Problems solved by technology

[0003] At present, there are two main repairing technologies in oilfields: one is to repair the casing by extruding the bellows with the conical head, and the wall of the bellows is flattened and expanded to directly cover the defects of the closed casing. Since this purely mechanical expansion is accompanied by The diameter of the pipe rebounds, so loosening and leakage will occur in a short period of time after repair; the other is to set up a long intermediate transition pipe for defects with long shapes or the situation where the location of repairing leaks is not easy to be accurately determined, and use covering defects to seal both ends, The casing is repaired by forming a sealed space, but when the rigidly fastened interface is subjected to repeated alternating stresses, it will gradually loosen and fall off, and finally even the mending device will become a "falling fish" and fall into the well

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