There are two main approaches to frac fluid design that are most common today: slickwater and high viscosity gel.
Slickwater frac jobs use high volumes of water commonly combined with friction reducer (FR) and minimal chemical additives to form a cost effective and simple frac fluid.
High viscosity gel frac jobs require a gel polymer that is hydrated in water to form a highly viscous and complex frac fluid. Special care needs to be taken during the hydration process and chemicals need to be introduced following the placement of proppant in order to breakdown the gel and produce it back to the surface.
EnQuest has designed a versatile hydration system that can produce frac fluids for both slickwater and gel fracs and can hydrate liquid gel concentrate (LGC) or dry gel polymer. The system has two dry material hoppers that can handle either FR or dry gel polymer. The system can also pump liquid gel concentrate from an offboard source.
Depending on the design of the fluid – either the FR or gel is mixed with base water to form a concentrate. The concentrate is diluted with water in a specially designed multi-compartment tank with gates, weirs that allow the mixture to hydrate before it is introduced to the slurry blender. pH meters and viscometers are installed to continuously monitor the fluid. Chemical additive systems can be included to introduce specialized chemicals into the mixture.
EnQuest’s hydration system run automatically through onboard controls or manually by an operator.