Sleeve Type Internal and External Centralizers

Abstract

The invention relates to a shaft sleeve type inside-and-outside centralizer. The shaft sleeve type inside-and-outside centralizer mainly solves the problem that in the prior art, the compatibility between a washover pipe column and a well and the compatibility between the washover pipe column and a sleeve are poor. The shaft sleeve type inside-and-outside centralizer is characterized in that an inner sleeve (5) and an outer sleeve (7) are connected to the outer side and the inner side of the middle section of an upper connector (1), a plurality of inner centering blocks (9) are fixed to the inner side of the inner sleeve (5), a plurality of outer centering blocks (8) are fixed to the outer side of the outer sleeve (7), balls (4) are embedded in the space between the upper end of the outer sleeve (7) and the upper connector (1) and the space between the lower end of the outer sleeve (7) and the upper connector (1), balls (4) are embedded in the space between the upper end of the inner sleeve (5) and the upper connector (1) and the space between the lower end of the inner sleeve (5) and the upper connector (1), and wear-resisting hard alloy is laid on the outer centering blocks (8) through welding. According to the shaft sleeve type inside-and-outside centralizer, the compatibility between the washover pipe column and the well and the compatibility between the washover pipe column and the sleeve can be effectively achieved for sleeve replacement of a directional well, and turning force for washover along the track of the well is provided for the washover pipe column.

Description

technical field

[0001] The invention relates to a centralizer in the technical field of oilfield engineering, in particular to a shaft sleeve type inner and outer centralizer. Background technique

[0002] At present, in the workover of petroleum engineering, the casing milling pipe string structure adopted by the vertical well casing replacement technology is casing milling head + casing milling barrel, and there is no special centralizer for casing milling. At present, during the casing construction of directional wells, due to the poor compatibility between the casing milling string and the casing, and the casing milling string and the borehole, the The force caused the construction to jump seriously, break up the casing, stop the turntable, or even cut off the casing, and casing milled a new wellbore. This makes it impossible to replace the sleeve to repair the damaged well. Therefore, it is necessary to develop a special centralizer for casing milling. Solving the com...

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