Rotatable hydraulic expanding type tail pipe hanger

Abstract

A rotatable hydraulically expandable liner hanger is used in liner cementing construction. The feature is that the upper end of the feed-in joint is threaded and can be connected with a drilling tool. The outer wall of the lower end of the feeding joint is splined with the expansion pipe; the inner wall of the lower end of the feeding joint is screwed into the central pipe. The lower end of the central tube is fixed with a sealing rubber plug by shear nails; the expansion plug is in the annular space between the central tube and the expansion tube; the rubber plug conduit is connected to the lower end of the expansion tube; the lower end of the rubber plug conduit is threadedly connected to the lower connecting pipe; the blocking ring is placed on the inner shoulder of the lower connecting pipe. The diameter of the central hole at the upper part of the blocking ring is the same as the outer diameter of the lower end of the sealing rubber plug, and the diameter of the central hole at the lower part of the blocking ring is smaller than the outer diameter of the lower end of the sealing rubber plug. The effect is that the tailpipe is suspended by utilizing the hydraulic pressure to expand the expansion pipe to closely contact with the casing inner wall. High hanging success rate, good sealing quality; large internal diameter of the pipe string. The spline connection between the feeding joint and the expansion pipe can be drilled with the drill bit rotating during the lowering process.

Description

Technical field: [0001] The invention relates to the technical field of petroleum cementing, in particular to a liner hanger for liner cementing, which is a rotatable hydraulically expandable liner hanger. Background technique [0002] The liner suspension cementing technology can reduce the overlapping of cementing casings and save casings; reduce the pressure of cement injection; simplify the well structure and solve the cementing problems of deep wells and complex wells. [0003] At present, liner hangers can be divided into slip type and expansion type liner hangers according to their mounting methods. Generally speaking, the slip type liner hanger has unreliable seat hanger, the diameter becomes smaller after the seat hanger, the seat seal effect is not good, there is a problem of seal leakage in the cement ring of the casing annulus, and there is also a problem of loss of hands after running the tool failure etc. [0004] Chinese patent announcement number CN2159452Y...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a rotatable hydraulically expandable liner hanger to complete the cementing of the liner hanger, and to overcome that the slip type liner hanger adopts the slip seat hanger, the seat hanger is unreliable, and the diameter of the seat hanger is too small. Smaller; to overcome the shortcomings of the expansion liner hanger, which adopts the method of expanding the expansion tube from the top to the bottom, and the structure is complicated

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