METHOD OF CONCURRENT-SEPARATE OPERATION OF MULTIPLE-ZONE WELL AND ADMISSION VALVE FOR PERIODIC SHUTTING OFF FLOW FROM FORMATIONS Russian patent published in 2001 - IPC

FIELD: production of fluid minerals; applicable in operation of oil and gas wells. SUBSTANCE: method provides for selective operation of producing formations with the help of admission valve installed against each formation and controlled from wellhead. Each valve has two fixed positions OFF and ON. Changing over from one position to the other is effected by pressure pulse from wellhead. Each valve has its own threshold action. Opening and closing of valve are accomplished by successive supply of two pulses of pressure: for action of desired valve and for action of next valve adjusted for lower pressure. Valve consists of body, core with intake holes and spring under end of core. Core ends have stops. One stop enters recess ring in body with two types of recesses successively alternating in depth. Stop of the other core in valve changing over enters recess ring with curved recess in body from the other side ensuring core turning in its axial motion. EFFECT: arbitrary selection of number and location of opened formations in multizone well designed for concurrent operation for the fullest utilization of each formation potentialities. 2 cl, 4 dwg