RETRIEVABLE WHIPSTOCK SYSTEM

摘要

2125772 9409243 PCTABS00032 A retrievable whipstock system is provided for use on a single trip into a wellbore to cut a window (8) through a casing wall (4) for passage of a drillstring used to drill a sidetrack borehole. The retrievable sidetrack system includes a mill (14) for both starting and cutting the window through the casing, and a whipstock (20) having a deflector surface for directing the mill into the casing to cut the window. A cylindrical head (18) is included within which is releasably secured a stabilizer sleeve (16) for reducing vibration of the mill during cutting of the window to extend the service life of the mill. A whipstock anchor (24) releasably secures the whipstock within the casing, and is settable, selectively releasably, and further releasably resettable so that the whipstock may be repositioned and reoriented within the wellbore numerous times.