At the well number 57 Nikiforovskoe field (in the Orenburg region) with a mobile drilling rig MBU-125 at a depth of 3113m was set hydraulic type whipstock BS-146.

Since the well has a large wall thickness and, correspondingly, the small inner diameter of the entrance, to strckle hole with a full-size gauge diameter of 122.0 mm was not possible. To save customer's time to prepare wellbore, "DI" company was suggested to perform work of window cutting with two trips.

On the 3-d of July 2012- it was RIH the whipstock assembly with the whipstock were conducted with special transporting device. After the orientation by compact telemetry system GNOM-1 and anchor setting a shear bolt was cut by tension 9t.

On the 4-th of July 2012 – by the second trip a mill FD -121.7 mm was RIH. It was started the window cutting. After POOH the mill to the surface the diameter of mill was measured. It was not lost.

We wish to the crew to finish the drilling safely in required time at the well number 57 Nikiforovskoe field !