WELL BORING METHOD AND DEVICE Russian patent published in 2005 - IPC

FIELD: mining industry, particularly methods and devices for deep well drilling from under casing shoe, for instance for oil, gas and water well boring.

SUBSTANCE: method involves drilling well; lowering and cementing casing pipe; lowering reamer and performing boring from under casing shoe. Drilling is performed for depth increasing casing string height along with forming shoe chamber. Lowering and cementing of casing pipe is carried out after shoe chamber filling with sand. Drilling from under casing shoe if performed after reamer lowering into shoe chamber, flushing thereof and adjusting reamer relative well axis. Boring device comprises drilling string, reamer having body with eccentric rock-cutting and centering blades and pilot-chisel. The reamer body is provided with lock and opposite guiding members arranged under the lock. One blade is eccentrically formed from eccentric rock-cutting blade. Eccentric and adjusting blades are movably connected with guiding members through connecting sleeves having means for fastening thereof. Connecting sleeve of adjusting blade in lower position is installed on guiding members. Connection sleeve of eccentric rock-cutting blade is mounted on the lock. Lock is formed with taking into consideration eccentricity of eccentric rock-cutting blade.

EFFECT: increased operational reliability, stability and efficiency.

5 cl, 1 dwg, 1 ex