Automatic grouting hoop floating shoes

Abstract

The invention discloses an automatic grouting float collar and float shoe. Casing pipe threads are machined at the upper and lower ends of a float collar body (1) or the upper end of a float shoe body (1) and connected with petroleum casing pipes, a guiding cap is installed at the lower end of the float shoe body (1), a stop valve seat (2) is connected to the inner wall of the body (1) through a straight thread, an inclined surface is machined at an inner hole of the stop valve seat (2) as a sealing surface, a stop valve (3) is installed below the stop valve seat (2), the sealing face of a valve body is a spherical surface, a shearing mechanism (4) and a flow control valve (6) are fixedly connected to the portion, on the inner wall of the body (1), below the stop valve seat (2) through high-strength concrete (7) in a sealed mode, the flow control valve (6) is located below the shearing mechanism (4), and an alloy ball (5) is thrown into the shearing mechanism (4). In drilling operation, automatic grouting and automatic flow-limiting designing are performed, in this way, it is effectively avoided that in the process of lowering the casing pipes, surging pressure causes lost circulation, and the product is good in drillability, resistant to corrosion and good in well-cementation quality.

Description

technical field [0001] The invention relates to the technical field of petroleum tools, in particular to an automatic grouting floating hoop and a floating shoe used in the drilling process of petroleum and natural gas. Background technique [0002] As important casing accessories, floating hoops and floating shoes directly affect the quality of cementing. At present, the existing floating hoops and floating shoes are mainly composed of a body, a restrictor plate, a stop valve seat, an alloy ball, and a guide cap. [0003] The utility model patent of Chinese patent No. 03269873.9 discloses a floating hoop and a floating shoe with reverse flow restriction for automatic grouting. The upper and lower ends of the floating hoop body or the upper end of the floating shoe are processed with casing threads connected with the oil casing, and the floating shoe The lower end of the body is equipped with a hemispherical round cap (that is, the guide cap). The inner wall of the body is ...

AI Technical Summary

Problems solved by technology

[0005] 1. Unable to realize automatic current limiting: the material of the current limiting plate is mostly steel material, and the size of the diversion hole cannot be deformed to the required requirements during the mud circulation process, so the upward return flow rate, upward return speed and reverse direction of the mud in the annular space The current limit time cannot be controlled

[0006] 2. Most of the materials are steel pipe and steel plate structure, which has poor drillability, and the sealing surface is easily corroded when exposed to acidic environment, resulting in seal failure

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