DEVICE FOR PREVENTION OF COMPLICATIONS IN WELL Russian patent published in 1994 - IPC

FIELD: oil producing industry. SUBSTANCE: device has body with channels communicating pipe inner space and drill string-borehole annulus, and extended truncated hollow cone submersible in body 1. Body has turning levers 5 ending in heads 4 which converge in center of body 1 to form truncated hollow cone when acting on levers 5 of plungers 7 located in radial cylindrical holes 12 for coincidence of radial channels 8 and circular channels 9 with channels 11 in wall of body 1. In this case, inner space of drill string is communicated with drill string-borehole annulus. Ball check valves 2 are provided with turning levers 5. So when stack of hydrogen sulfide appears in drill string-borehole annulus, pressure in it rises, valves 2 and channels 11 open to communicate drill pipe inner space with drill string- borehole annulus. Due to this, drilling mud with hydrogen sulfide starts circulating in face region without its getting to the surface up to its full neutralization. Device prevents ejection of hydrogen sulfide to day surface. EFFECT: higher efficiency and prevented contamination of environment with hydrogen sulfide. 6 dwg