Creating Value for the High-Saline Bakken Produced Water by Optimizing its Viscoelastic Properties and Proppant Carrying Tendency with High-Viscosity Friction Reducers

Since the arrival and advancement of horizontal drilling and hydraulic fracturing (hydrofracturing) technologies, developing and producing unconventional formations like the Bakken Formation have become a mystery solved for operators in North America. This has also made unconventional reservoir assets the central focus of the oil and gas/energy industry at the state, national, and global levels. However, the produced water from these activities has high salt contents (∼110,000 to 350,000 ppm) total dissolve solids (TDS) in the Bakken Formation) and poisonous if untreated and in contact with the environment. The most common disposal method in the Bakken Formation is deep injections into disposal wells. However, there have been some fears that continuous injections, in addition to contaminating the ground water, could potentially lead to seismic activities either at the time of injection or in the near future. If treated and made fit for its respective applications, this water could be reused in the hydrofracturing process, thereby reducing operator costs of water acquisition and disposal. In addition, it could be used for power generation or to support coal mining and irrigation. Previous studies have discussed various means of improving the quality of the produced water. However, none have been able to cope with the issue of wastewater and residual oil high in TDS. This paper aims to study all relevant means that allow the Bakken Formation to produce water that can be used as an alternative based fluid for use with polymers like high viscosity friction reducers (HVFRs) to make hydraulic fracturing fluids that will be stable with reservoir conditions and able to reduce environmental footprints and operating costs. This research presents an experimental investigation using the Bakken Formation's hypersaline water with HVFRs. This work includes experimental research divided into base case scenarios that serve as a standard for comparison of the effectiveness of the other cases. The results show that the Bakken water high in TDS treated with higher dosages (4–8 GPT) of HVFRs withstand the effect of hardness, salinity, and heavy metals and remain stable at various shear rates (66–330 s⁻¹). No treatment was done on the Bakken produced water except filtration and dilution.