Evaluation of Fluid Behaviour and Mixing Efficiency in Predefined Serpentine Micro-Fracture System

Abstract

Scientific research and development in the field of microfluidics and nanofluidics technology has witnessed a rapid expansion in recent years. Microfluidic and nanofluidic systems are finding increasing application in wide spectrum of biomedical and engineering fields, including oil and gas technology. Fluid flow characterization in porous geologic media is an important factor for predicting and improving oil and gas recovery. By developing understanding about the propagation of hydraulic fracturing fluid constituents in irregular micro- and nano-structures, and their multiphase interaction with reservoir fluids (e.g. mixing of supercritical CO2 with oil or gas) we can significantly improve efficiency of the current oil and gas (O&G) extraction process and reduce associated environmental impacts. In present paper, mixing of hydraulic fracturing fluid constituents in three dimensional serpentine microchannel system is simulated in CFD environment and results are used to evaluate mixing efficiency for different fracturing fluid compositions. In addition, pressure drop along the length of serpentine micro-channel is evaluated. Serpentine micro-channels considered in this study consist of periodic symmetrical and asymmetrical proppant particles, placed on both sides of the channel over the full length of the channel, to simulate realistic geometrical constraints usually seen in geological fractures. The fluid flow is characterized as a function of the proppant particle radius by varying size of adjacent proppant particles. Further, the flow is characterized by varying distance between adjacent proppant particles. Overall, this study will be primarily helpful to gain fundamental understanding of fracturing fluid mixing in micro-fractures, similar to real geologic media. In addition, this study will provide an insight into variations of fracturing fluid mixing efficiency, and pressure drop in micro-fracture systems as a function of geometry of the proppant particles at different flow rates.