WELLHEAD LOCK (VERSIONS) Russian patent published in 2002 - IPC

FIELD: oil, gas and mining industries. SUBSTANCE: according to the first version, wellhead lock has gate installed on upper flange of wellbore, device for opening of wellbore in the form of high-pressure gas source located in wellbore under gate, vessel with ground closed from upper end and secured to gate. Vessel is made in the form of flexible hose containing sealed gate installed on wellbore at an acute angle to horizon. Vessel lower part with length not less than height of ground layer above well is located under gate and sealed with its lower end face to wellbore upper flange. In this case, strength of fastening of vessel lower part to wellbore upper flange is less than strength of vessel material. Strength of fastening of vessel lower part so wellbore flange may be maximum in place of minimal distance between gate and wellbore flange. According to the second version, wellbore lock has gate and cover located under it, installed on wellbore upper flange are device for opening of wellbore in the form of high-pressure gas source located in cavity between gate and cover, vessel with ground closed from top end and secured to gate. Vessel is made in the form of flexible hose accommodating high-pressure gas source with sealed gate installed at an acute angle to horizon. Vessel lower part located under gate with length equaling at least ground layer height above well end surface is sealed to cover lower surface. Installed on vessel side surface under gate may be a knife for its cutting under action of flexible tie-rod connecting knife to cover. In this case, length of flexible tie-rod is less than length of vessel lower part, but larger than or equal to ground layer above well. In both versions, entire vessel or its lower part may be made of rubberized fabric reinforced from outside with net, for instance, capron net. In both versions, wellhead lock may additionally have embracing vessel with ground shell made in the form of truncated cone or truncated pyramid facing ground surface with its large end face and connected to wellbore located under it with its small end face. Shell internal surface may be coated with antiadhesive coating. Proposed invention may be used in quick opening of dormant or exhausted mines used as storages, oil, gas and hydrogeological wells. EFFECT: reduced specific consumption of materials of wellhead lock and wellbore, and higher reliability of opening. 10 cl, 8 dwg