METHOD AND DEVICE FOR DOWNHOLE TREATMENT OF WELL Russian patent published in 1997 - IPC

FIELD: oil industry. SUBSTANCE: treatment of well downhole zone infested with paraffined, asphaltic-resin or slime deposits is performed by filling a well with liquid of comparatively high density and creating water column pressure corresponding to stratum pressure. Then, depression chamber and pyrotechnic charge are brought into productive stratum. Used is slowly burning pyrotechnic charge with burning velocity of 1.5-2.5 mm/s ensuring emission of gases with high temperature. Burning is effected prior to creation of depression. On completion of burning, technological time-delay is exercised to allow gaseous burning products within productive stratum to be displaced with borehole liquid. After that, depression is created with displacement of borehole liquid from downhole zone and subsequent inflow of plug-liable components. Device for realization of aforesaid method has depression chamber with pyrotechnic charge and detonator connected with ground-surface control unit. Device is provided with burning housing connected through slotted metal sleeve with inlet valve unit of depression chamber. Unit is made up of case and valve proper with seal. Valve has inner space and holes in its walls. Space is capped atop with nut having side holes. Firing pin is seated in nut with its large diameter part. Located above firing pin is striker held from falling by a rod made of easy-fusible and burning material. Located on rod is heating coil connected with electric wires. Pyrotechnic charge with detonator is enclosed in burning housing. Inner space of inlet valve body communicates with depression chamber hollow. EFFECT: efficient cleaning of well downhole zone from slime generating components. 3 cl, 1 dwg