DOWNHOLE VALVE Russian patent published in 2004 - IPC

FIELD: well drilling equipment, particularly devices for preventing sludging of drilling machines, eliminating kick of gas and liquid through drill column.

SUBSTANCE: downhole valve includes hollow body, conical valve seat arranged in body and shutoff unit performing axial movement between valve seat and limiting grate. Shutoff unit has core cooperating with valve seat and closing through passage between core and hollow body. Valve includes conical elastic cup, additional conical seat, additional shutoff unit and additional limiting grate having guiding orifice. Hollow body comprises upper and lower halves. Conical seat, shutoff unit and limiting grate are arranged in lower body half. Elastic cup is fixed to core and provides passage closing by flared end thereof. Additional shutoff unit includes core and elastic conical cup for partial closing bypass channel created in upper body half by core. The elastic cup may perform axial movement between additional conical seat and additional limiting grate having guiding orifice. Tail core portion is disposed in guiding orifice of additional limiting grate. Cavity of lower base half communicates with space surrounding body above conical seat by radial orifices. Elastic diaphragm is installed in lower body half for opening radial orifices with the purpose of entering well liquid from space surrounding body under well liquid head.

EFFECT: extended operational capabilities, increased reliability and service life.

4 cl, 4 dwg