Hole shrinking sliding sleeve

Abstract

The invention provides a hole shrinking sliding sleeve. The hole shrinking sliding sleeve comprises an upper connector, a hole shrinking mechanism and a positioning mechanism. The lower end of the upper connector is sequentially connected with an outer sleeve and a lower connector. The hole shrinking mechanism is provided with an upper sliding sleeve. The lower end of the upper sliding sleeve is connected with a lower sliding sleeve, a pushing rod penetrates through the upper sliding sleeve, and a retractable ball base is arranged between the pushing rod and the lower sliding sleeve in a clamping mode. The positioning mechanism is located below the hole shrinking mechanism, and is provided with a connecting barrel. A sliding barrel and a base penetrate through the connecting barrel, the sliding barrel axially and movably penetrates through the base, and a positioning rod and a piston are arranged between the base and the connecting barrel in a clamping mode. A plurality of clamping grooves are formed in the upper end of the positioning rod, the upper end of the sliding barrel is arranged inside the clamping grooves in a clamping mode, and the piston is connected to the connecting barrel. The hole shrinking sliding sleeve can be opened by putting steel balls with the same diameter, the opening of the hole shrinking sliding sleeve is not limited by the diameter of the put balls, the large drift diameter of a fractured tubular column is guaranteed, the number of the improved steps of oil layers is increased, and operating risks are reduced.

Description

technical field [0001] The invention relates to a ball-throwing sliding sleeve, in particular to a reducing sliding sleeve for downhole fracturing of an open-hole horizontal well in an oil field. Background technique [0002] At present, open-hole horizontal wells in oil fields mainly use "open hole packer + step-by-step ball-sliding sleeve" fracturing string for well completion and fracturing. The multi-stage ball-sliding sleeve used in this fracturing string has a The casing corresponds to the next oil layer in the well, and the inner diameter of the ball sliding sleeve corresponding to each oil layer becomes larger from bottom to top, and the opening and fracturing of each layer of the ball sliding sleeve are completed by dropping steel balls of different diameters from the wellhead. [0003] The size of the above-mentioned pitching sliding sleeve is limited by the size of the pitching ball. In order to meet the opening of the pitching sliding sleeve at different position...

AI Technical Summary

Problems solved by technology

When multiple oil layers in a horizontal well section are stimulated and fractured, the size of the multi-stage ball sliding sleeve installed on the horizontal well fracturing string will increase step by step with the increase in the number of oil layers. However, the ball sliding sleeve The size of the horizontal well fracturing string cannot be increased indefinitely, which will increase the size of the horizontal well fracturing string, which will not only increase the production operation cost, but also increase the operation risk. Therefore, the horizontal well fracturing string in the prior art uses The advanced ball sliding sleeve cannot meet the requirements for fracturing multiple oil layers, and it cannot meet the needs of the current oil and gas field development, and because the inner diameter of the ball sliding sleeve in the lower layer of the downhole is small, it cannot meet the requirements of large-volume sanding fracturing and post-processing. Needs for lowering in-pipe working tools

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