Then, if needed, they use slurry to stabilize the hole. Both methods have ideal applications dependent on soil variables. But some say casing holes have several advantages that justify investing in costly Oscillators and rotators. It also is more environmentally attractive than slurry, says Mike O'Neill, a University of Houston civil engineering professor who predicts more resistance to slurry ahead. Some contractors are not convinced.
Oscillators are safer and more efficient but also more costly to operate.