DEVICE FOR SIMULTANEOUS DRILLING AND FIXING OF AREAS OF HEAVING AND COLLAPSES DURING DRILLING OF A WELL Russian patent published in 2021 - IPC E21B7/20 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, namely to the drilling of oil and gas wells with simultaneous isolation of areas of heaving and collapse when drilling a casing string. The device contains a drill and casing strings, a rock-breaking element. The rock-breaking element is made in the form of a drill chisel screwed to the lower end of the casing string on a thrust conical thread and equipped with a seat for the ball. In the upper part of the casing string, a hermetically sealed adapter is installed with dowels inserted into the matching grooves made at the upper end of the casing. The adapter is equipped with a chisel with a hole for passing the ball from below, and a groove inserted into the narrowing of the casing string from above. The angle of taper of the chamfer of the adapter groove is made so that when exiting through the narrowing of the casing, an additional expansion of the upper part of the casing is provided. The adapter is provided with a thread on the top for connection to the drill string, and the outer narrowing of the casing string is provided with an elastic element with an outer diameter equal to the diameter of the casing string. The diameter of the casing string is 10-15% smaller than the diameter of the chisel being drilled.

EFFECT: provides an increase in the reliability of the device, the exclusion of emergency situations associated with a change in the pressure drop, drilling with an optimal flow of washing liquid and drilling the bit without lifting the layout.

1 cl, 1 dwg