Inventors:
Jack C. Cowan - Lafayette LA, US
Roy F. House - Houston TX, US
Julie B. Morgan - Houston TX, US
James A. Meyer - Rayne LA, US
International Classification:
C09K 8/60
Abstract:
The invention provides a fluid loss control additive for oleaginous liquids and oleaginous wellbore fluids containing the additive. The additive is the reaction product of a tannin compound, a polyamidoamine, a commercial lecithin, and an acid. The preferred tannins are derived from quebracho and wattle trees. The preferred acid is sulfuric acid. The preferred polyamidoamine is a long-chain fatty alkyl partial amide which is the reaction product of a polyalkylenepolyamine and a fatty acid containing from about 8 to about 30 carbon atoms, most preferably tall oil fatty acids, wherein at least one of the amino groups of the polyalkylenepolyamine is not amidated. The commercial lecithin contains from about 30% to about 50% of the vegetable oil from which the lecithin is concentrated, preferably soybean oil, and is present in the additive in an amount from about 1% to about 3% by weight, based on the weight of the tannin. Preferably the additive contains greater than 15% by weight of the polyamidoamine, based on the weight of the tannin.