The weighting agent may be added up to 21 pounds per gallon in one embodiment, and up to 19.5 pounds per gallon in another embodiment.In another embodiment, the water-based drilling fluid may include a gelling agent. The gelling agents suitable for use in the fluids disclosed herein may ...
De-icing fluid is also supplied to the ground nozzle 34 through conduit 89 having a check valve 90 and a 3-30 gallon per minute variable flow restrictor or proportioning valve 92 therein. A two and one-half gallon per minute fixed flow restrictor valve 94 is connected in parallel across th...