WELL DRILLING DEVICE Russian patent published in 1995 - IPC

FIELD: oil and gas industry. SUBSTANCE: well drilling device has a branch pipe, a cylinder, and a rod. These components are mounted in eccentric conjugation for limited reciprocal motion and transmission of torque. The branch pipe is joined to the upper part of a column of pipes, and the rod is joined to its lower part. A rubber packer is secured on the rod. The lower part of the column of pipes is arranged so that at full travel depth the device is in the casing string, and the bit is under load as required. The device is provided with spheres in seats on the external surface. A plug is mounted on shear pins in the central channel of the device. The device is provided with a system of channels for delivery of fluid to the bit in the process of drilling as well as delivery of fluid in the annulus area in replacing the washing solution without lifting the tool. It is possible to pass instruments to the bit through the casing string, and the area at the well bottom hole can be isolated as a blow-out is about to start. EFFECT: higher efficiency; higher reliability. 2 dwg