Casing string applying toe end sliding sleeve to full-drift-diameter sliding sleeve and using method thereof

Abstract

The invention discloses a casing string applying a toe end sliding sleeve to full-drift-diameter sliding sleeves and a using method thereof. The casing string comprises multiple casing pipes (1), a sliding sleeve accessory, the multiple full-drift-diameter sliding sleeves (2) and the toe end sliding sleeve (3). According to the casing string applying the toe end sliding sleeve to the full-drift-diameter sliding sleeves and the using method thereof, the toe end sliding sleeve (3) is used for establishing a first-section fracturing channel, and when it comes to a complex structural well, the phenomenon that the well is stuck can be effectively avoided; an infinite fracturing method of the full-drift-diameter sliding sleeves (2) is used, and full drift diameter is achieved; and a soluble fracturing ball (8) with the drift diameter of more than 100 mm after being dissolved is used to adapt to the inner diameter of each casing pipe (1), so that smoothness of the casing string is ensured.

Description

technical field [0001] The invention relates to the field of petrochemical industry, in particular to a casing string using a toe-end sliding sleeve to a full-diameter sliding sleeve and a use method thereof. Background technique [0002] In the field of petroleum, fracturing refers to a method that uses hydraulic action to form cracks in oil and gas layers during the process of oil or gas recovery, also known as hydraulic fracturing. Fracturing is to artificially create fractures in the formation, improve the flow environment of oil underground, increase the production of oil wells, and play an important role in improving the flow conditions at the bottom of oil wells, slowing down interlayers and improving the production status of oil layers. [0003] Fracturing technology has been widely used in the oil field, but at present, in order to realize the commercial development of shale gas, it is imperative to reduce costs and increase efficiency. The staged fracturing of shal...

AI Technical Summary

Problems solved by technology

[0005] (1) For horizontal wells, wells with complex structures such as multi-branches, it is easy to cause stucking in continuous operation of pumping bridge plugs and construction of coiled tubing;

[0006] (2) For the complex trajectory of the horizontal section, especially if the well type is upturned, the continuous operation of coiled tubing and pumping is prone to self-locking and pumping failure.

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