Soluble toe end sliding sleeve for well cementation and well completion and use method thereof

Abstract

The invention relates to the field of oil field development, in particular to a soluble toe end sliding sleeve for well cementation and well completion, and a use method thereof. The soluble toe end sliding sleeve for well cementation and well completion comprises an upper joint and a lower joint, wherein a first through hole is formed in the axial direction in the upper joint; the upper end of the lower joint is inserted into the upper joint; an annular cavity is formed in an overlapping surface of the lower joint and the upper joint; a second through hole is formed in the axial direction inthe lower joint; a first groove is formed in a position, positioned in the annular cavity, of the inner wall surface of the upper joint; and a second groove is formed in a position, positioned in theannular cavity, of the outer wall surface of the lower joint. A high-intensity soluble alloy inner sleeve is arranged between the upper joint and the lower joint, so that a tool and a tubular column meet a high-pressure-bearing requirement in the well cementation colliding pressing process; and automatic dissolution is realized in a later period, so that the inside and outside communication of thetool is realized. Through the wall surface recess treatment on the wall bodies of the upper and lower joints, the effective isolation of the inner sleeve from well fluid is ensured; meanwhile, pipe body weakness is artificially preset; and when a liquid inlet inner sleeve of a sealed cavity needs to be dissolved, pressurized opening can be easily realized, and the opening is reliable.

Description

technical field [0001] The invention relates to the field of oilfield development, in particular to a soluble toe-end sliding sleeve for well cementing and well completion and a use method thereof. Background technique [0002] After the cementing is completed, the wellbore is a closed cavity. In order to provide a liquid entry channel for the later fracturing, it is necessary to open a casing at the toe of the completion string and its external cement sheath to communicate the wellbore and the formation. For the wells with a reservoir depth of 3500m and a horizontal section length of less than 1500m, conventional coiled tubing or cable-carried downhole crawlers are used to perforate with hydraulic or firepower perforating guns. For wells with a reservoir depth of more than 3500m and a horizontal section length For wells with a length of 1500m, the above method is ineffective due to the flexible feature of the coiled tubing, and the crawler has requirements on the cleanlines...

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Problems solved by technology

[0003] Patent Publication No. CN107288602A discloses an electronically controlled toe end fracturing sleeve. The invention is based on infinite electromagnetic wave control. Reliability is greatly affected by well depth and well temperature, and it is prone to failure, and cannot be opened after failure

[0007] Among the various casing connection tool methods provided by the prior art, some of them open the ports through mechanisms such as air chambers, rupture discs, and electronic control components. Due to the mechanism design, the tools are complicated, the wall thickness is thick, and the inner diameter is relatively small. Casing running changes greatly, and cementing is difficult. At the same time, due to the characteristics of electromagnetic components that are prone to failure when exposed to high temperature and humidity, the tools are used in complex and changeable well conditions, and the stability is uncontrollable, and there is no remedial measure after failure; There is also the blasting type, which is destructive and dangerous to a certain extent, especially in the operation of gas wells, which has great safety hazards

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