Dynamic sealing device for rotary blowout preventer

Abstract

The invention relates to a dynamic sealing device for blocking a rotary blowout preventer between a drill column and a borehole in drilling of oil-gas fields. The dynamic sealing device overcomes the defects that the conventional dynamic sealing device has short service life, is quick in heat emission and is easily sintered. The invention adopts the technical scheme that: a supporting ring is arranged in a packing box, the supporting ring is provided with an oil hole b and an oil hole c, and the outer surface of the supporting ring is provided with an annular groove b; a disc spring is arranged in the supporting ring, a caulking ring is arranged at the lower part of the disc spring, and the supporting ring is arranged between the caulking ring and a pressure ring; the pressure ring is provided with an oil hole a, and a V-shaped sealing ring and a spacing ring are sequentially arranged at the lower part of the pressure ring at intervals; a packing pressure ring is arranged at the lower end of a floating ring, the packing pressure ring is fixed at the end of the packing box, and the packing pressure ring is in clearance fit with a central pipe bush; and the central pipe bush is in interference fit with a central pipe, the packing box is in interference fit with an upper shell of the blowout preventer, and lubricating oil enters an oil hole in the upper shell of the blowout preventer through a bearing. The dynamic sealing device is suitable for relatively high dynamic sealing pressure, reduces sintering of the sealing ring, has low heat emitting abrasion and long service life, and reduces the abrasion rate.

Description

technical field [0001] The invention relates to a dynamic sealing device of a rotary blowout preventer used for sealing off the annular space between the drill string and the well bore in the drilling process of oil and gas fields. technical background [0002] The rotary blowout preventer is an indispensable key equipment for underbalanced drilling. During the drilling process, it can isolate the drill string and the annular space, realize drilling while spraying, and guide the return fluid away from the wellhead. At present, the rotary blowout preventer has been localized, and many domestic companies have achieved mass production of the rotary blowout preventer, and the overall technology is basically mature. However, the life of the rotary blowout preventer seal is relatively low, especially the dynamic sealing device of the rotary blowout preventer, which has a short field service cycle and increases the maintenance man-hours; in addition to the short life, another impor...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a dynamic sealing device for rotating blowout preventers in order to solve the shortcomings of the existing dynamic sealing device of rotating blowout preventer such as short life, quick heat generation and easy sintering.

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