Patent ID: 7066285
Filing Date: 2006-06-27
Classification: C09K,Y10S

Abstract:
1. A method of preventing or alleviating lost circulation of drilling fluid in a wellbore penetrating a subterranean formation at intermediate depths less than about 15,000 feet, said method comprising treating said wellbore with a lost circulation material or composition comprising a synergistic blend of a resilient carbon-based material and a water-swellable but not water-soluble crystalline synthetic polymer capable of preventing or alleviating lost circulation without addition of reinforcing materials; said blend comprising the carbon-based material and the synthetic polymer in a ratio ranging from about 70 ppb to about 90 ppb carbon-based material to about 2 ppb to about 10 ppb synthetic polymer, and alcohol to facilitate the combination of the carbon-based material and the synthetic polymer.