The mechanisms of inhibition and lubrication of clean fracturing flowback fluids in water-based drilling fluids

Abstract This study presents a novel approach for the reuse of uncontaminated fracturing flowback fluids to improve the inhibitory and lubricating properties of water-based drilling fluids (WBFs), curb environmental pollution arising from flowback fluids, and substantially mitigate the expenses associated with WBFs. The experimental design was optimized using orthogonal experiments and range analyses, whereby the modified rubber powder was set at 2.0%, xanthan gum at 0.15%, and a plant phenol to modified complexing agent ratio of 1:0.01. The assessment of the performance evaluation tests indicated that the use of uncontaminated fracturing flowback fluids as the base water can remarkably enhance the inhibitory and lubricating properties of WBFs. Precisely, this approach reduces the linear expansion rate from 62.31% to 21.25%, the reduction rate of extreme pressure lubrication coefficient by 87.98%, and the reduction rate of mud cake sticking factor by 59.86%. This investigation has established the potential environmental and economic benefits of reusing clean fracturing flowback fluids in WBFs.