Owens Corning
Asphalt water-based drilling fluid additive

Abstract:

An emulsified drilling fluid additive includes an emulsion of asphalt, at least one emulsifier, cellulose ether, and water. The asphalt has a softening point of 160 to 212.degree. F., a penetration depth of 0 to 45 mm, and a viscosity of 200 to 800 cP at 350.degree. F. The drilling fluid additive has an average particle size of 0.1-10 microns. The drilling fluid has an API fluid loss at 7.5 minutes of 0 to 0.5 mL and an API fluid loss at 30 minutes of 0 to 3.5 mL. A method of making the drilling fluid additive includes mixing at least one emulsifier, cellulose ether, and water to form a solution, heating a water-dispersible asphalt to above 300.degree. F. and adding the asphalt to the water-based solution in a colloid mill to form an emulsion.