PROCESS OF RUNNING OF SEA OIL-AND-GAS FIELD AND DEVICE FOR ITS REALIZATION Russian patent published in 1994 - IPC

FIELD: production of oil and gas on sea shelf, mainly under ice conditions. SUBSTANCE: device includes casing string with extension piece and means for shutting off of string manufactured in the form of nonreturn rotary clack valve tightly coupled with extension piece over length of its entry into body of clack valve corresponding to its full opening. For creation of moment of turn of clack valve and for its holding in closed position clack valve is provided with weight installed outside body. With worsening of ice condition extension piece is screwed out of device and casing string is tightly shut off. For resumption of running extension piece is screwed into shutting off device with effort exceeding that of its shutting off. EFFECT: enhanced operational reliability and safety. 2 cl, 1 dwg