The present invention provides a drilling fluid composition and a method of drilling
comprising a drilling fluid, which may be oil- or water-based, and a composite
microsphere component. The invention drilling fluid composition advantageously
reduces the density of a conventional fluid, reduces costs associated with pumping
and overcomes problems associated with conventional gas-injection processes. The
invention uses conventional drilling and pumping equipment, requires no sea-floor
based pumps and may be easily pressure-controlled to maintain the pressure of the fluid.
