Recovery of synthetic-based mud depends on removal of LGS
After drilling several horizontal wells in Argentina, Total wanted to use the recovered synthetic-based mud to drill the next well. However, the mud contained more than 10% LGS that could not be eliminated mechanically by traditional solids-control equipment due to the small size of the solids incorporated in the mud.
Unconventional wells in the region are designed with lateral sections of 6,562 ft [2,000 m] or more drilled with mud densities from 1.7 sg [14.2 lbm/galUS] to 2 sg [16.7 lbm/galUS].