Annular preventer for drilling and workover in oil field

Abstract

The invention provides an annular preventer for drilling and workover in an oil field, belonging to the technical field of drilling equipment. The annular preventer for drilling and workover in the oil field comprises an upper end cover, a shell and a preventer core, wherein the upper end cover is assembled with the shell through a bolt component; the preventer core is arranged in a cavity enclosed by the upper end cover and the shell; a slip assembly, a vertically-arranged packing element and a rigid torsion transfer drum are arranged in the preventer core; a packing element upper torsion conduction shaft and a packing element lower torsion conduction shaft are respectively arranged at the upper and lower ends of the packing element; the packing element upper torsion conduction shaft is of a hollow structure, and the inner wall of the packing element upper torsion conduction shaft is a circular conical surface matched with the slip assembly; and the torsion transfer drum sleeves outside the packing element. The annular preventer for drilling and workover in the oil field has the characteristics of strong high pressure resistance, good universality and long working life and is suitable for conventional down-hole operation, operation under pressure and under-balanced drilling operation.

Description

technical field [0001] The invention relates to a drilling and workover blowout preventer, in particular to an annular blowout preventer suitable for oil field drilling and workover operations, and belongs to the technical field of drilling equipment. Background technique [0002] In the process of oil and gas drilling and workover, in order to avoid out-of-control blowout accidents, it is necessary to install a blowout preventer on the wellhead. As the main component of the blowout preventer, the blowout preventer must not only have certain pressure resistance, but also After the blowout preventer is rotated, drilling operations can also be carried out without snubbing. [0003] The diameter design of the existing annular and spherical BOPs is based on the outer diameter of the working pipe coupling, and the diameter of the annular and spherical BOP is required to be slightly larger than the outer diameter of the working pipe coupling, and the difference between the two is ...

AI Technical Summary

Problems solved by technology

[0003] The diameter design of the existing annular and spherical BOPs is based on the outer diameter of the working pipe coupling, and the diameter of the annular and spherical BOP is required to be slightly larger than the outer diameter of the working pipe coupling, and the difference between the two is within 20mm , to ensure the interference pressure bearing capacity of the pressure bearing cross section of the rubber rubber tube, so the above blowout preventer cannot adapt to the drilling and workover construction operations of large span, multi-standard downhole strings, and tool combination composite technology

In addition, due to the small diameter and poor pressure bearing capacity of the existing underbalanced drilling rotary annular BOP, there are generally defects in the following aspects: First, it cannot guarantee the passage of multiple tools with different diameters, so it is difficult to switch large diameter tools. It is necessary to replace the matching blowout preventer; second, when the variable diameter part of the working string passes through, it is easy to cause damage to the rubber sleeve; third, when using a large diameter rubber sleeve with a small diameter string, under pressure , the cross-sectional deformation of the rubber rubber tube is too large, and the rubber tube will burst and fail due to outflow and overturning. It is under the strong pressure of the hydraulic medium, but also bears a large shear stress, which shortens its working life

The above problems make it difficult for the existing underbalanced drilling rotary annular blowout preventer to be widely used

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