Effects of Alternative Water Sources on Formation and Proppant Pack Damage Reduction Properties of Near-residue-free Fracturing Fluid

Russell, Aaron (Halliburton) | Singh, Dipti (Halliburton ) | Schnoor, Eli (Halliburton)

OnePetro 

This work examines how the use of high salt content waters (i.e., produced and flowback water) in conjunction with a recently developed, virtually residue free (res-free) hydraulic fracturing fluid affects the cleanup properties of the system. The res-free fluid system is designed around a naturally low residue polymer that, upon breaking, causes significantly less damage to the formation and proppant pack compared with conventional, guar-based fracturing fluids.
Since its introduction, guar-based fluid technology has grown to dominate the hydraulic fracturing industry due to its reliability and cost-effectiveness. However, guar gum contains a significant amount of insoluble residue that is not removed during its processing. The residue can cause damage to both the proppant pack and the hydrocarbon-bearing formation when the broken fluid is flowed back following the fracturing treatment. This damage can impair hydrocarbon flow from the formation and through the propped fracture, resulting in lower production over time. The res-free fluid offers better cleanup upon breaking than guar-based fluids and therefore significantly higher proppant pack conductivity and formation permeability in laboratory testing.
The res-free polymer exhibits sensitivity to certain ions present in solution, both in terms of gel hydration and crosslinking behavior. Depending on the ions present in the water and their respective concentrations, manipulation of the chemical formulation of the crosslinked res-free fluid system can mitigate these effects and achieve a stable, highly viscous fluid suitable for hydraulic fracturing. This work investigates whether the necessary reformulations impact the regained permeability and conductivity of the fluid system. Rheological data demonstrating how the reformulated fluid compares to standard formulations is presented. Additionally, test results are presented highlighting the effects of the alternative water sources on the res-free fluid regained permeability and conductivity data.
The use of produced and flowback waters for fracturing operations can substantially reduce both the economic and environmental impact of fracturing operations. The combination of the res-free fluid’s ability to utilize these water sources and its excellent damage reducing properties provides a system with significant advantages over conventional technologies in many applications.