Novel Hydraulic Fracturing Fluid Supporting the Sustainability Initiatives for Freshwater Conservation

Abstract

Abstract Harnessing energy from natural gas has become critical in today's energy mix globally, and it is just as important locally to supply parts of the domestic energy demand. Hydraulic fracturing technology has made the extracting of such resources, often from tight reservoirs, quite possible. However, fracturing is associated with large freshwater use. In light of the on-going efforts to provide means for water conservation and sustainable freshwater usage, the newly developed pond water based fracturing fluid presents great freshwater conservation opportunity in hydraulic fracturing operations by re-use of discard water from evaporation ponds. Sufficient quantity of water is located in the regions where the majority of hydraulic fracturing operations take place. This water which is discard from Natural Gas Liquification (NGL) plants has very high re-use potential in hydraulic fracturing operations. Protecting and conserving the groundwater resources by providing an alternative water resource to carry out major upstream operations is perceived with a great priority. The water quantity and quality of the pond, available at NGL plant, was evaluated for re-use opportunity, especially for fracking operations, with favorable geochemical composition (Total dissolved solids around 2,500 ppm). The developed technology can potentially conserve up to 250 million gallons of freshwater per year by replacing it with the pond water from a single NGL plant. In this paper we present the development of a novel hydraulic fracturing fluid utilizing this discard water. Systematic developmental study leading to successful field application were undertaken for the new pond water based fracturing fluid, targeting high temperature carbonate gas reservoirs. Several laboratory performance tests were judiciously undertaken to compare the performance of the new fracturing fluid with conventional systems. Experimental studies including rheological characterization, thermal stability, scale inhibition and formation damage profiling are reported. The new fracturing fluid demonstrated excellent high temperature stability, compatibility with acid fracturing fluids and minimal formation damage compared to conventional freshwater fracturing fluids. Utilization of a novel scale inhibitor was implemented specifically to avoid any scale formation due to the fracturing fluid. Field stimulation treatments using the new pond water based fracturing fluid showcased excellent flowback performance with no reservoir damage. It was demonstrated that developed pond water based fracturing fluid can utilize the discard water from NGL plants without any pre-treatment. Thus, making this technology highly cost effective to the alternate fresh water technologies currently available in the market for hydraulic fracturing. This showcases the robustness and cost effectiveness of this technology. The novelty of the new fracturing fluid is the value it adds to the utilization of alternative water resources by contributing to the sustainability, circular water economy and fresh water conservation initiatives.