Grinding shoe for underground milling in oil field

Abstract

The invention discloses a grinding shoe for underground milling in an oil field, which comprises a grinding shoe body, a cemented carbide column is fixed at the bottom of the grinding shoe body, the grinding shoe body is made into a cylindrical shape, and A group of centralizers with balls are evenly distributed along the circumference on the surface, and the balls on the centralizers with balls can roll. T-shaped cutting inserts are respectively installed in the grooves. The invention does not wear out when working, and has small frictional resistance with the casing wall. The T-shaped cutting blade fits with the T-shaped groove on the grinding shoe body, and the blade will not fall off; the flank face of the T-shaped cutting blade forms an α angle and the rake face of the T-shaped cutting blade forms a β angle. During the milling process, the chip can be broken quickly, and the iron filings can be quickly washed away by the mud; there is a set of grooves on the T-shaped cutting blade, and when the blade collapses, the blade will not break completely.

Description

technical field [0001] The invention relates to a milling shoe for downhole milling in an oil field and a manufacturing method thereof, belonging to the technical field of downhole milling tools. Background technique [0002] In the middle and late stages of oilfield exploitation, as the oil well is getting deeper and deeper, accidents that drill pipes or other tools fall into the well often occur during the drilling process. This just needs to use grinding and milling tool to grind the downhole falling objects, and then the falling objects are fished out from the downhole. [0003] At present, when the flat-bottomed grinding shoes used in the oil field are used to grind downhole falling objects, the grinding efficiency is low due to the small number of blades and the short effective cutting length. Moreover, the center of the grinding shoe will be excessively worn, forming deep pits and even the center of the grinding shoe is hollowed out. Or all the cemented carbide parti...

AI Technical Summary

Problems solved by technology

[0003] At present, when the flat-bottomed grinding shoes used in the oil field are used to grind downhole falling objects, due to the small number of blades and the short effective cutting length, the grinding and milling efficiency is low, and the grinding shoe center will appear. Excessive wear will form deep pits and even hollow out the center of the grinding shoe, or all the hard alloy particles on the surface of the grinding shoe will be knocked off and bare, resulting in premature failure of the grinding shoe, and a mud layer will be attached to the surface of the grinding shoe to form a mud bag. abnormal use

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