Pond Water Based Acid Fracturing: Novel Approach to Improve Sustainability

Abstract It has been widely recognized on a global scale that both fracturing water-based fluid systems and acid fluid systems predominantly utilize fresh water as their main resource. One of the most promising sustainable solutions is the innovative use of pond water for fracturing treatments, which has shown great potential in reducing reliance on fresh water sources. The concept of utilizing produced water as a base fluid for domestic high-pressure, high-temperature (HPHT) fracturing applications represents a novel advancement in the field. Encouraging results from fluid research, alongside extensive laboratory testing, have demonstrated the viability of substituting fresh water with alternative sources. This led to successful field trials involving pond water-based fracturing operations, aimed specifically at conserving fresh and groundwater resources. Both zirconate crosslinked and borate crosslinked fluids were meticulously reformulated to provide optimal rheological properties when mixed with pond water. The trial campaign not only proved the reliability of these systems at elevated bottom hole temperatures but also demonstrated their compatibility with acid fluid systems, passing all necessary tests without significant alterations. Rheology data and compatibility testing have convincingly shown the effectiveness of the optimized formulation for pond water in high-temperature wells. Several trial stages were executed in rig-less stimulation operations, remarkably without any incidents related to health, safety, or environmental concerns. The introduction of pond-sourced water into fracturing operations at high temperatures (reaching up to 315°F) in vertical wells was successfully implemented within an acid fracturing fluid system. The first trial well was subsequently opened for flowback, yielding promising results and an excellent gas production rate. Overall, the pond water trial campaign significantly lowered the consumption of fresh groundwater, achieving impressive average savings of around 1,700 barrels of fresh water for each fracturing treatment conducted. The authors estimate a potential conversion rate of up to 18% of conventional fracturing operations during the initial commercial year, with further expansion of the method anticipated. Ultimately, the estimated potential for saving fresh water could reach as high as 50% annually. This paper presents a comprehensive overview of the novel methodology employed in utilizing pond water as a source for acid fracturing fluid systems applied in HPHT carbonate formations. This innovative approach contributes significantly to sustainable water conservation efforts, addressing the excessive use of fresh water by leveraging produced water (Ajayi et al., 2013; Economides & Nolte, 2000; Kalgaonkar et al., 2021).