Asuperior poWder form of a metallic soap for enhancing the properties of an invert emulsion drilling ?uid may be prepared by a dry process saponi?cation reaction. The process includes mixing a source of metal cations With the product of a Diels-Alder reaction of dienophiles With fatty acids and/or resin acids and alloWing the mixture to react. Heating the mixture increases the rate of reaction. The solid product is ground to form a poWder. The properties of the drilling ?uid that may be improved by adding the soap include ?ltration control, ?uid loss control, emulsi?cation and emulsion stability, and electrical stability.