and starch derivatives biopolymers such as xc and xanvis and derivatives of biopolymers and surfactant based systems such as viscoelastic surfactant fluids commonly known in the industry as clear frac offered by schlumberger and surfraq offered by baker oil tools some friction reducers may be preferred over others based on the specific conditions of the gravel pack completion the type of friction reducer may be selected based on compatibility issues with the completion brine compatibility issues with the filter cake the formation temperature and the circulating temperature the desired shear stability the ability to form an alpha and beta wave and control the dune height or the ability to transport gravel down alternate flow path tubes shunt tubes offered by schlumberger and direct pack tubes offered by baker oil tools the use of a hec or biopolymers known as xc or xanvis may provide the desired combination of friction pressure and compatibility characteristics with completion brine and filter cakes to make them preferred in many but not all applications the use of viscoelastic surfactants ves may be desired in other applications to reduce friction pressure and transport the gravel or filtration media and their use is disclosed in this invention the concentration of the polymers in the industry is usually referred to in pounds of polymer per thousand gallons pptg but other concentrations such as.