Patent ID: 8252730

Claim:
A method of treating a subterranean formation of a hydrocarbon well comprising providing a water-based wellbore treatment fluid containing: at least 30 g/l of one or more viscoelastic-gelling carboxylic acids and/or alkali metal salts thereof, wherein the carboxylic acids have the formula R 1 COOH, where R 1 is an optionally substituted aliphatic alkyl group of 15 to 21 carbon atoms; at least 1 g/l one or more solubilising alkylolamines; and at least 40 g/l of one or more water-soluble inorganic alkali metal salts, wherein the carboxylic acids and/or alkali metal salts thereof and the alkylolamines are present in the fluid in respective amounts such that, at 25° C., the alkylolamines solubilise a portion of the carboxylic acids and/or alkali metal salts sufficient to render the fluid viscoelastic, and the fluid also contains a further portion of the carboxylic acids and/or alkali metal salts thereof which form a suspension of solid particulates in the fluid; and injecting the fluid into the well, while said further portion of the carboxylic acids and/or alkali metal salts thereof is present as a suspension of solid particulates in the fluid; such that said further portion dissolves and causes an increase in viscosity upon exposure to higher temperatures below ground.