Packing type graded cementing device

Abstract

The invention provides a packing type graded cementing device. One end of a body is connected with a packer base pipe, and a circulating hole is formed in the body. The body sleeves a closing sleeve and an opening sleeve, the closing sleeve is located at the end, away from the packer base pipe, of the body, and the opening sleeve is located between the closing sleeve and an expansion sealing base.A part capable of being matched with a closing plug is arranged in the closing sleeve, and a part capable of being matched with an opening plug is arranged in the opening sleeve. A rubber sleeve is arranged on the packer base pipe, a sealed cavity can be formed between the rubber sleeve and the packer base pipe, and a liquid injection channel is formed between the packer base pipe and the sealedcavity. A closing valve is arranged on the liquid injection channel. The expansion sealing base is located at an inlet of the liquid injection channel in the packer base pipe. A part matched with theopening plug is arranged in the expansion sealing base, and the expansion sealing base can move in the axial direction. The opening sleeve can move in the axial direction, and the closing sleeve can move in the axial direction to close the circulating hole. Annular well hole packing can be achieved, the structure is simple, operation is easy, and safety and reliability are achieved.

Description

technical field [0001] The invention relates to the technical field of downhole cementing equipment for petroleum and natural gas, in particular to a pack-off type graded cementing device. Background technique [0002] After oil and gas wells are drilled, casings need to be lowered for cementing operations. The two-stage cementing technology can solve some technical problems in the cementing construction of deep and ultra-deep wells, such as large amount of cement injection at one time and long construction time. The fracture pressure of the formation is low, and the cement cannot return to the designed well depth and other problems. The graded water injector with annulus isolation function can realize the isolation of the upper and lower annular open holes of the graded cementing device after the first-stage cementing is completed, blocking the transmission of liquid column pressure, which can directly reduce the pressure on the formation at the bottom of the well, Protect...

AI Technical Summary

Problems solved by technology

[0003] Existing methods that can achieve annulus isolation during staged cementing include designing the staged cementing device and packer in one piece, and triggering the The function of the packer, some structural packers have the problem of premature expansion and sealing, and the safety and reliability are poor

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