Effect of nanoparticle inclusion in fracturing fluids applied to tight gas-condensate reservoirs: Reduction of Methanol loading and the associated formation damage

Abstract

Hydraulic fracturing is one of the most common stimulation operations for increasing the productivity of a well. The fracturing fluid is one of the key factors in the operation and must accomplish some special requirements and behavior. The fluid that remains inside the fracture and the reservoir after the fracturing operation is finished, causes severe damage to the proppant pack and the formation, leading to a lower efficiency of the stimulation. This study presents experimental research on adding nanoparticles to a commercial fracturing fluid commonly used for tight gas-condensate reservoirs, aiming to enhance its performance in rheological behavior and its capacity to reduce the formation damage associated with the use of fracturing fluids. Nanoparticles with mean particle sizes of 8 and 19 nm with basic and acidic surface modifications were employed for modifying a commercial fracturing fluid. Rheology tests were performed at pressure and temperature conditions of 1.38 MPa and 104 °C, respectively, for the different nanoparticles at dosages of 100 and 200 mg/L. The improvement of those properties enabled the modification of the original formulation of the fluid, reducing the amount of methanol, one of most expensive and hazardous additives, by up to 33%, and reducing the formation damage by approximately 71%. Furthermore, this modified fluid was evaluated in terms of its impact in the wettability of the rock and its relative permeability to water and oil through static (contact angle measurements) and dynamic tests (relative permeability curves). The modified fracturing fluid showed an excellent capability to improve the water-wettability of the rock and also decreased the relative water permeability by 83%. This work demonstrates the suitability of adding nanoparticles to fracturing fluid for stimulations where it is necessary to reduce the relative permeability of water, acting as a Relative Permeability Modifier (RPM) in a conformance for a fracturing operation.