Foam or mist drilling process

Claim 1

IN A FOAM DRILLING PROCESS INWHICH AIR IS CIRCULATED DOWN A BOREHOLE IN CONTACT WITH THE DRILL BIT AND SAID AIR CONTAINS A FOAMING AGENT ADAPTED TO MIX WITH WATER IN THE BOREHOLE TO FORM A FORM FOR REMOVAL OF CUTTINGS FROM THE BOREHOLE, THE IMPROVEMENT COMPRISING INJECTING THE FOAMING AGENT IN AN AQUEOUS SOLUTION INTO THE CIRCULATING AIR, AND DISPERSING A SULFURIZED COMPOUND SELECTED FROM THE GROUP CONSISTING OF SULFURIZED UNSATURATED FATTY ACIDS HAVING MORE THAN 8 CARBON ATOMS PER MOLECULE, SULFURIZED ROSIN ACIDS, SULFURIZED UNSATURATED FATTY ALCOHOLS OF HIGH MOLECULAR WEIGHT, SULFURIZED ESTERS OF UNSATURATED FATTY ACIDS HAVING MORE THAN 8 CARBON ATOMS PER MOLECULE AND SULFURIZED UNSATURATED FATTY ACID PITCHES IN THE AQUEOUS SOLUTION IN AN AMOUNT OF ABOUT 0.025 TO 1% BY WEIGHT OF THE SOLUTION TO FORM A PROTECTIVE COATING ON THE SURFACES OF THE DRILL BIT, SAID SULFURIZED COMPOUND CONTAINING 1/2 TO 20% SULFUR.