| 摘要 |
FIELD: oil-and-gas production. ^ SUBSTANCE: in assembly of activator, pistons 8 are fitted in channels 10 to make keys 12 with plates 22 screwed thereto sliding along T-shaped slots 16 of case 1 via piston orifices 18. To extend pistons 12 and cutting elements 6 onto inner surfaces 81 of pistons 8, drilling fluid if forced therein. At reached preset pressure, screws 20 are destructed to make aforesaid pistons displacing from inside position to outside position. Downhole tool comprises drill bit, activator and cutting element arranged on one or every piston of activator. Method of borehole enlargement exploits above described borehole tool. ^ EFFECT: decreased friction feedback with pistons in rotation of enlarging tool and higher reliability. ^ 19 cl, 47 dwg |
