Transport and Distribution of Proppant in Multistage Fractured Horizontal Wells: A CFD Simulation Approach

Abstract

Multistage hydraulic fracturing has become the key technology for completion of horizontal and vertical wells. The perf and plug method is the most commonly used staging method. In each stage, multiple perforation clusters are used, attempting to create a separate transverse fracture at each cluster. How these clusters are placed can significantly affect both short-and long-term production performance. Simultaneous creation of multiple fractures is a cost-effective and time saving method for stimulating both vertical and horizontal wells. Multistage fracturing is an effective method in terms of completion efficiency; however, achieving even proppant distribution to each cluster is an intricate task that proves to be challenging within the industry.Numerical simulations predict uneven proppant distribution of the fluid streams entering different perforation clusters. Field data indicates, in many cases, that some of the clusters do not contribute to production. This led to hypothesizing that actual proppant and fluid distribution along the stimulated clusters can differ from the assumed uniform distribution. However, with respect to limited-entry frac design, the proppant distribution among the different perforations is assumed to be the same as the fluid distribution. Until recently, this assumption remained unchallenged. This paper presents extensive study and investigation of proppant transport in different perforation clusters within a single stage by using computational fluid dynamics (CFD) techniques. Effects of varied fluid and proppant specific gravity, viscosities, proppant sizes, and slurry flow rates were analyzed while maintaining outside-casing parameters constant. Validation of empirical proppant transport CFD simulation results are compared to experimental test data. This is helpful to gaining a better understanding of fluid and proppant behaviors in multi cluster fracturing processes to achieve maximum efficiency.The results of the study indicate that proppant transport can be accurately modeled when the effects of single particle settling, density driven flow, particle velocity profiles, and slurry rheology are all considered. The investigation demonstrates that CFD is an effective tool for optimizing proppant distribution among perforation clusters and enhancing production.

Numerical study of the effect of uneven proppant distribution between multiple fractures on shale gas well performance

“…In addition, Crespo et al [16] observed the phenomenon of uneven proppant distribution within three perforation clusters through conducting a large-scale experimental study to mimic the plug-and-perf operation, and it will be more severe in cases with higher proppant density and smaller flow rates. Bokane et al [20] used computational fluid dynamics (CFD) technique to simulate proppant transport in different perforation clusters within a single stage and to understand the phenomena of uneven proppant distribution within perforations. However, the impact of uneven proppant distribution between different clusters within a single stage on ultimate gas recovery has not been evaluated quantitatively.…”

Migration Law and Influence of Proppant in Segmented Multicluster Fracturing Wellbore of Deep Shale Horizontal Well

“…According to the experimental results, they found that fluid velocity and proppant properties (type and size) are the main factors affecting the uneven distribution of proppant in each perforation diameter [11,12]. Bokane et al studied the distribution of proppant in each cluster of fractures considering factors such as proppant particle size, density, fracturing fluid viscosity, and pumping displacement through large-scale laboratory experiments, and they found that high displacement, high viscosity and small particle size, and low-density proppant can improve the nonuniform sand injection effect of each cluster [13]. Yi et al used the Eulerian multiphase flow model to fit Freddy Crespo's laboratory test results, and verified the feasibility of Eulerian multiphase flow in simulating proppant migration in a wellbore [14].…”

A liquid‐solid model to optimize the application of friction reducers for hydraulic fracturing/cutting in the underground coal mine

“…21 The numerical approaches are widely applied 22 because of its advantages of revealing the internal flow mechanism of the solid-liquid two-phase and the flow details that are difficult to obtain experimentally. 23,24 To capture the physics of coal particle transport in fracturing fluid flow, the two key numerical approaches available in the literature are the Eulerian-Lagrangian method 25 and the Eulerian-Eulerian method. 24 The Eulerian method models the continuous phase by solving the mass and momentum conservation equations, and the solid phase (coal particle) is modeled by tracking particle motion using Newton's second law of motion.…”

“…24 The Eulerian method models the continuous phase by solving the mass and momentum conservation equations, and the solid phase (coal particle) is modeled by tracking particle motion using Newton's second law of motion. 25 For tracking discrete phases, the Lagrangian and Eulerian methods are coupled to analyze the particle-fluid system issues existing in industry. 26 The two most common Eulerian-Lagrangian methods used in the literature are the discrete particle method (DPM) 27 and the computational fluid dynamics-discrete element method (CFD-DEM).…”