METHOD AND DEVICE FOR UPWARD DRAIN BOREHOLE FORMING Russian patent published in 2006 - IPC E21B43/10 E21B7/24 

FIELD: mining, particularly to develop mineral deposits, to construct underground systems from underground mine tunnels in difficult hydrogeological conditions.

SUBSTANCE: method involves installing device comprising drilling head and filtering string with hydraulic-pneumatic percussion mechanism in borehole; performing borehole drilling along with flushing thereof; penetrating water-bearing horizon along with hydraulic pulses application thereto during filtering string lowering. In the case of borehole drilling in solid rock zones device provided with cleaning unit is used. The cleaning unit is fixed to hydraulic-pneumatic percussion mechanism. Filtering string includes concentric inner and outer filtering tubes, which are extended during filtering tube lowering into water-bearing horizon. Additional hydrodynamic pulses are applied during borehole drilling when drilling tools penetrate solid rock zones, when drilling tool is stuck inside borehole and during repeated hydraulic-pneumatic percussion mechanism lowering in borehole. Device comprises drilling head connected to sub, filtering string, casing and delivery pipes, packer and hydraulic-pneumatic percussion mechanism supported by delivery pipes. The device is also provided with cleaning unit, which is fixed to hydraulic-pneumatic percussion mechanism with clamp. Filtering string includes inner and outer filtering tubes. Inner filtering tube may slide relatively outer one during tube lowering in water-bearing horizon and inner surface cleaning with the use of cleaning unit. Hydraulic-pneumatic percussion mechanism is connected to packer by lower end and to sub by upper end thereof. Upper hydraulic-pneumatic percussion mechanism end is connected to sub by means of centering bush having groove, which provides hydraulic-pneumatic percussion mechanism and packer lifting and lowering in well. Cleaning unit may be automatically disconnected from hydraulic-pneumatic percussion mechanism during hydraulic-pneumatic percussion mechanism removal from borehole and may be automatically connected to it during hydraulic-pneumatic percussion mechanism lowering in well.

EFFECT: prevention of drilling rate decrease and drilling tool sticking.

2 cl, 3 dwg