Patent ID: 7767628

Claim:
A method for drilling a well comprising the steps of: adding an effective amount of a foaming composition to a hydrocarbon base fluid to form a foamable hydrocarbon drilling fluid, where the foaming composition comprises a polymer or a gelling agent and a cross-linking agent or mixtures or combinations thereof; and mixing the foamable hydrocarbon drilling fluid with a gas under conditions to dissolve the gas in the fluid to form a pre-foam including an amount of solubilized gas sufficient to produce a foam having a foam height of at least 150 mL and a half life of at least 2 minutes based on 100 mL of fluid, when the pre-foam undergoes a pressure drop, pumping the pre-foam into a drill string while drilling, where the pre-foam prevents pump cavitation or vapor locking encountered in traditional gas-liquid drilling fluid combinations, producing a foam when the pre-foam undergoes the pressure drop and the pressure drop is sufficient to convert the pre-foam into the foam, where the foam decreases a weight of the fluid column, increases a fluid removal rate from the well and increases removal of cuttings and other entrained materials in the foam, and withdrawing the foam from the well.