METHOD FOR PRESSURIZATION OF INTER-COLUMN SPACE OF OIL AND GAS EXTRACTIVE WELL MOUTH BETWEEN CONDUCTOR AND OPERATION COLUMN AND DEVICE FOR REALIZATION OF SAID METHOD Russian patent published in 2005 - IPC

FIELD: oil and gas industry.

SUBSTANCE: method includes cutting conductor at height of mouth armature mounting place and cutting operation column at level no lower than plane of flange for mouth armature. For realization of method a device with elements for holding and supporting operation column and pressurizing elements is manufactured. Device is made of two, upper and lower, stepped-shape bushings interconnected by thread. Upper bushing is made with outer thread at upper end, inner thread at lower end for connection to lower bushing, with outer shelf for upper end of conductor and outer diameter lower than shelf for inner diameter of conductor. On upper end inside the bushing a ring-shaped recess is made and a ring channel with inner shelf for upper pressurizing element. Below the shelf in body of bushing a through radial channel for connection of behind-column space to pressure manometer through branch pipe and locking tool is made. Lower bushing is made with outer shelf, below which its outer diameter is made for inner conductor diameter, and inner longitudinal channel is made for outer diameter of operation column. Elements for holding and supporting operation column are made in body of lower portion of lower bushing in form of no less than three cylindrical channels, placed evenly around the bushing at an angle from outside into inside of longitudinal axis of bushing, lower open ends of which channels are outputted into inner longitudinal channel of bushing. Into slanted cylindrical channels balls are loaded, spring-loaded on upper side. Device is subjected to prior assemblage, according to which balls are loaded into cylindrical channels in body of lower bushing, above these springs are mounted and compressed as needed via screwed stops. Lower pressurizing elements are mounted at outer shelf, onto upper portion of lower bushing upper bushing is screwed along thread, though without compression of lower pressurizing elements. In such preassembled state device with its inner longitudinal channel of lower bushing is placed on operation column through its upper end and lowered into inter-column space of well mouth until outer shelf of upper bushing is supported by upper end of conductor. Then upper pressurizing element is mounted in ring recess on inner shelf on the side of upper end of upper bushing. After that replacing flange is screwed below mouth armature onto upper end of upper bushing of device body. Due to full exclusion of welding operations, higher industrial safety of operations at mouths of oil and gas wells during pressurization of inter-column space between conductor and operation column of well is provided for.

EFFECT: lower laboriousness, lower costs, higher safety.

2 cl, 1 dwg