CONTROLLABLE WHIPSTOCK ASSEMBLY Russian patent published in 2008 - IPC E21B7/08 

FIELD: drilling equipment, particularly special apparatus for deflecting the boring, namely special drill bits, knuckle joints, whipstocks, which set design directional or horizontal well bore deflection angle.

SUBSTANCE: whipstock assembly 8 comprises central shaft 3 with sealing means and outer threads. Central shaft 3 has section bent through α angle. Clutch 1 is arranged outside central shaft 3. Clutch 1 has the first end with end teeth. Kick sub 2 is screwed on one end of central shaft 3. The kick sub 2 has end teeth cooperating with that of the clutch. Straight sub 4 touching clutch end 1 is screwed on another end of central shaft 3. The whipstock assembly 8 includes four centering parts L, L1, L2, L3 including radial space between outer surface of central shaft 3 and inner surface of subs 2 or 4 arranged over central shaft. Radial space defined at said parts should not exceed that of threaded connection between central shaft 3 with subs 2 and 4. Centering parts L, L1 are made in central shaft 3 and in sub 4. Centering parts L2, L3 are created in central shaft 3 and sub 2.

EFFECT: increased accuracy of well drilling and increased whipstock assembly service life.

3 cl, 5 dwg