Our old customer encountered with problem of exit from 7 " casing on Dobrovolsky oilfield. It was decided to cut a window in casing and continue next drilling with 6-1/8” bit. In order to use the cased hole as much as possible the window should was cut at 12729 ft. with orientation at 62 degrees zenith angle.

To the oilfield from DDI Drilling Innovation yard was delivered 6.181” reaming mill and KLEN -7 whipstock was shipped to Novy Urengoy earlier.

Landing of hydraulic whipstock with two reaming mills by expansion was conducted for one trip. During the same trip the orientation, anchoring , shearing and milling of full size window was done.