Xanthan gum has been used extensively as a viscosifier in coiled tubing due to its unique friction reduction properties. In this paper we describe the friction pressure properties of a new, previously introduced, biopolymer for use in coiled tubing applications. The name of the polymer is diutan. Diutan yields higher low shear rate viscosities at lower polymer concentrations than xanthan gum due to its higher molecular weight. Diutan is more shear thinning that xanthan gum. As a consequence, the high shear rate viscosities of diutan are lower than those of xanthan gum at comparable low shear rate viscosities.
Large scale friction pressure tests in coiled and straight tubing were conducted to observe if the lower high shear rate viscosities of diutan translated into lower friction pressures. The results of these tests showed that both xanthan and diutan exhibited significant drag reduction. However, the percentage drag reductions of diutan were larger than those of xanthan gum.