Hollow Glass Microspheres itself is inert without pollution. As a continuous medium, low density drilling fluid with addition of hollow glass microspheres was incompressible, and all wells are uniform in density. Sludge cakes formed have good lubrication, reducing the risk of sticking. It is technically infeasible for drilling large deviated wells and horizontal wells since the recycled micro-foam and air drilling technology can not deliver MWD signal. However, hollow glass microspheres have an irreplaceable advantage for it can not affect the system signal.
