| 摘要 |
The invention provides a method of enhancing the recovery of shale-containing cuttings during the drilling of a borehole in a shale-containing subterranean formation which comprises adding to the drilling fluid circulating in the borehole a finely ground, very sparingly soluble, anhydrous, alkali metal silicate glassy material to provide the drilling fluid with a concentration of soluble silica in the range from about 0.1% to about 1.0% by weight of the aqueous phase of the drilling fluid. Preferably the drilling fluid has a pH in the range from about 8.0 to about 11.0, most preferably about 8.5 to less than 11Ø. The preferred alkali metal is potassium. |
