Composition and degree of polymerization of the degradable polymer and the selection of additives may be varied to adjust the viscosity, degradation time and other properties of the fracturing fluid....http://www.google.de/patents/US20030060374?utm_source=gb-gplus-sharePatent US20030060374 - Method and materials for hydraulic fracturing of wells Erweiterte Patentsuche Ver???ffentlichungsnummerUS20