DEVICE FOR WELL DRILLING AT WATER AREAS Russian patent published in 2013 - IPC E21B7/12 

FIELD: mining.

SUBSTANCE: device includes tubular shroud, annular impact tool with two spring-loaded rods and semi-annular plates and annular adapter of semi-annular plates from their horizontal position into uprightness and vice versa. The bottom end of the shroud is connected to the tubular striker, impact tool has an anvil and is telescopically connected to the striker and annular adapter is put on the shroud with the possibility of movement along it. The adapter mass is defined from condition of equality of its pressure force on the rods and tool spring force to compression at their operation in water from awash floating platform. Internal diameter of annular adapter is by 0.004-0.010 m more than the maximum external diameter of tubular shroud elements. The external diameter of adapter bottom face end is equal or more than the distance between external surfaces of impact tool rods. The edges of top and bottom face ends of adapter at its central annular channel are made with chamfering at an angle from 10 to 15 degrees and the height of chamfered edge amounts 0.01 m from adapter face end.

EFFECT: increase of drilling efficiency and reliability of string operation, provision of possibility to increase the depth of developed water areas.

2 cl, 5 dwg