Abstract: The addition of relatively small quantities of a bacterial cellulose to hydraulic fracturing fluids improves their rheological properties for hydraulic fracturing of geological formations. Proppant suspension is markedly improved and friction loss through well casings is significantly reduced, resulting in lower pumping energy requirements. Computer models also indicate that formation fractures will be propagated for greater distances as will the propped portion of the fracture. Normally only about 0.60-1.8 g of bacterial cellulose per liter of fracturing fluid is needed. A preferred bacterial cellulose is one made in agitated fermentors using mutation resistant strains of a bacterium from the genus Acetobacter.

Abstract: The invention relates to hydraulic fracturing of geological formations at selected levels of wells drilled for recovery of hydrocarbons. It resides in the addition of relatively small quantities of a bacterial cellulose to hydraulic fracturing fluids to improve their rheological properties. Proppant suspension is markedly improved and friction loss through well casings is significantly reduced, resulting in lower pumping energy requirements. Computer models also indicate that formation fractures will also be propagated for greater distances as will the propped portion of the fracture. Normally only about 5-15 lb of bacterial cellulose per 1000 gallons (0.60-1.8 g/L) of fracturing fluid is needed. A preferred bacterial cellulose is one made in agitated fermenters using mutation resistant strains of a bacterium from the genus Acetobacter.