METHOD FOR PERCUSSION-ROTARY DRILLING OF WELLS AND DEVICE FOR ITS REALIZATION Russian patent published in 1994 - IPC

FIELD: well drilling. SUBSTANCE: device has upper spindle 1 and lower spindle 2, body 3 with upper carrier 4 and lower carrier 5 screwed on body 3. Movably installed in body 3 is striker 6 centered in body by means of ball guides 7. Inner cavities of upper carrier 4 and lower carrier 5 and respective outer surfaces of spindles 1 and 2 are conjugating between each other for transmission of torque and axial relative motion in given design, e. g. , in form of polyhedrons. Striker 6 may be also made in form of two coaxial cylinders 8 and 9 with ball guides between them. Method is embodied as follows. Rotation of drill pipe string (in rotary drilling) or shaft of downhole motor is transmitted through spindle 1 to carrier 4, body 3 and carrier 5 and further on to spindle 2 and drilling bit connected to spindle 2. Drilling bit rolling over well bottom, executes vertical reciprocations transmitted through spindle 2 carrying freely striker 6 and body 3 with carriers 5 and 4, and spindle 1 on which part of string is loaded. Due to different masses of said independent members (spindle 2, body 3 with carriers 5 and 4, striker 6) start moving upward with different frequency and amplitude, and in reverse motion they deliver blows against working surfaces of spindle 2, and, consequently, against drilling bit rigidly connected to spindle 2. In so doing, in course of well deepening by rotation of cone bit with simultaneous application to it of static load and impact load by means of bottom hammer, the value of static load at preset rotation speed of drilling bit is maintained equal to the value not exceeding four masses of movable parts of bottom hammer. EFFECT: higher value and rate of penetration due to utilization on well bottom of energy of vertical reciprocations of drilling bit; prevented destruction of drill pipe string and proper formation of well bore. 4 cl, 4 dwg