A spin-type internal blowout prevention tool

Abstract

The invention relates to a self-rotary-type internal spraying-proof tool which is composed of an upper connector, an inner sleeve, an upper valve seat, a lower valve seat, a lower connector, screwed plugs and steel balls. The upper valve seat and the lower valve seat are each of a disc structure, six fan-shaped flow passages are evenly distributed on the upper valve seat in the circumferential direction, and six fan-shaped flow passages are evenly distributed on the lower valve seat in the circumferential direction; and the upper valve seat and the lower valve seat both adopt cone-shaped surface seal, and the upper valve seat and the lower connector keep still. Six spiral raceways are evenly distributed on the inner surface of the lower connector in the circumferential direction, the steel balls are installed in the spiral raceways, and the screwed plugs are adopted for blocking; and when the axial position of the lower valve seat is changed, the steel balls move along the spiral raceways, and movement of the steel balls causes circumferential rotation of the lower valve seat. According to changing of the pressure direction of a fluid, opening and closing of the internal spraying-proof tool are automatically adjusted, the flow passages are unobstructed, sealing is reliable, and the service life is long.

Description

technical field [0001] The invention relates to the field of well control equipment for oil and gas drilling, in particular to a spin-type internal blowout prevention tool. Background technique [0002] With the development of oilfield exploration and development towards deep bottom layer, low permeability and unconventional oil and gas, the formation conditions during the drilling process are complex and changeable. When the formation pressure is too high, it is easy to cause well kick or even blowout. Especially in the process of underbalanced drilling, the bottom hole pressure is high, and the blowout prevention tool in the drill string is an important part of the blowout prevention system. At present, internal blowout prevention tools mainly include plug valves, arrow valves, flap valves, bypass valves, and drop-in check valves. Among them, the cock valve has the problem of difficulty in opening and closing the cock and requires manual operation; the return spring of th...

AI Technical Summary

Problems solved by technology

Among them, the cock valve has the problem of difficulty in opening and closing the cock and requires manual operation; the return spring of the arrow valve and the flap valve is prone to failure, and the service life is unstable; the flow channel of the arrow valve is narrow, easy to block, and the sealing surface is easy to be damaged. Drilling medium and solid particles are eroded; the drop-in check valve needs to be put into the valve body from the wellhead, and the bypass valve needs to be put into the steel ball from the wellhead, which is inconvenient for manual operation and cannot respond to changes in bottomhole pressure in real time

Field application reflects: the failure rate of blowout prevention tools inside the drill string is very high, and the failure of inner blowout prevention tools seriously affects drilling safety

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