Ozone-Assisted Micro-Nano Bubble Treatment of Oily Drilling Mud: Viscosity Reduction, Oil Removal, and Filtrate Reuse Performance

The treatment of high-viscosity oil-bearing drilling mud from offshore platforms is constrained by limited space and stringent environmental regulations, yet no previous study has demonstrated the combined application of ozone-assisted micro-nano bubble (MNB) oxidation with filtrate recycling for this specific waste stream. Here, we address this gap by integrating ozone MNB treatment, flotation oil removal, and filtrate reuse into a unified process for the viscosity reduction and deoiling of water-based drilling mud. Experimental results show that the ozone MNB process achieves a viscosity reduction rate exceeding 50.2% and an oil removal rate of 60.87%, with filtrate ion concentrations (Ca2+ 382 mg/L, Mg2+ 1380 mg/L, SO42− 1107 mg/L) within reuse thresholds. Drilling fluid reformulated with the recycled filtrate maintains consistent rheological properties before and after thermal aging. These findings demonstrate that the coupled ozone MNB treatment-reuse strategy is scientifically viable for managing high-viscosity drilling waste, advancing beyond conventional disposal approaches by enabling simultaneous viscosity reduction, oil removal, and resource recovery within a compact process footprint.