Could Emulsified Friction Reducers Prevent Robust Friction Reduction?

摘要

Many of the friction reducers in use today demonstrate various degrees of performance based on the type of mixing water utilized, especially those products which are designed as an "emulsion" (Aften et al. 2009; Zelenev et al. 2009). In addition to molecular differences between various polyacrylamides, the nature of the oil external qualities of an emulsion can pose challenges to breaking (or inverting) the emulsions (Aften et al. 2009; Zelenev et al. 2009). These factors directly affect hydration rates and are dependent on water quality factors like salinity, dissolved materials, suspended materials, and pH (Aften et al. 2009; Zelenev et al. 2009). Therefore, it is postulated that if the friction reducers are applied in another form such as a powder or slurried powder, they could have an inherent broader spectrum of applicability and efficiency. The purpose of this study is to determine the differences in performance of several friction reducers in various water qualities in order to determine if the type of polymer application enhances or restricts the range of applicability. Multiple polyacrylamides are tested in different forms including oil external emulsions, powder, and slurried powder. These friction reducers are tested on a flow loop in up to four different water qualities including fresh water, 5% KCl, sea water, and produced water. The results of this testing show that some oil external emulsions are limited to smaller ranges of applicable water qualities. The powder polyacrylamide sample has a broad range of applicability, while the slurried powder shows comparable and often superior performance, especially in poor water quality. Switching to a slurried powder friction reducer would enhance operational simplicity and economies of scale by eliminating the need for several products. The percent polymer activity would also surpass that of emulsions which could ultimately reduce the total volume pumped and, in turn, cost, emissions, time, and truck traffic due to freight.