DRILL STEM EQUIPMENT WITH INTEGRATED RING BARRIER AND COLLAR WITH HOLE, METHOD AND SYSTEM Russian patent published in 2018 - IPC E21B7/20 E21B33/14 

FIELD: shipbuilding; mining.

SUBSTANCE: group of inventions relates to the field of well construction and in particular to ensuring the integrity of the wellbore in severe geological conditions with the rotation of the casing strings/shank during drilling, as well as other devices and techniques that improve the cementing of casing strings or shanks in the well in conjunction with the drill bit. For this purpose, the drilling system comprises an upper section of the casing string. It has a collar with holes, which provides an adjustable clearance from the inside of the upper section of the casing string to the annulus, surrounding the upper section of the casing string. Also the drilling system includes a lower section of the casing string. It is attached to the upper section of the casing string by means of a swivel. And the lower section of the casing string comprises an external casing packer. It is attached to the outer part of the lower section of the casing string. Said external casing packer is expandable against the borehole wall prior to the cementing operation. Wherein the upper section of the casing string is rotatable during the cementing operation, while the lower section of the casing string is substantially rotationally fixed relative to the upper section of the casing string. In addition, the drilling system further comprises a casing string liner. It is attached to the lower section of the casing string above the external casing packer and is configured to keep the lower section of the casing string rotationally stationary in the borehole. Inside the lower section of the casing string, a rotary control system (RCS) for positioning the bit with the body is located. To the inner shaft of the RCS a drill bit is attached.

EFFECT: increased efficiency of well casing.

16 cl, 6 dwg