drilling report due out today, page-7

The drilling muds cause this debris to rise to the top of the well for removal. In a lost circulation zone, this recovery of debris does not work for any number of reasons, such as cross flow or voids within the borehole.

Lost circulation can result in numerous other drilling problems including stuck drill pipe, damaged bits, slow penetration rates, and collapsed boreholes. Traditionally, lost circulation zones are filled with cement plugs. By filling the borehole with cement and then drilling through the cement, any cross flows or voids are blocked off which allows drillers the ability to remove drilling debris from the borehole.