Evaluation and Optimization of Proppant Distribution in Multistage Fractured Horizontal Wells: A 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. During 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 performances. 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 can 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.This paper presents an extensive optimization study and investigation of proppant transport in different perforation clusters within a single stage using computational fluid dynamics (CFD) techniques. Effects of proppant and fluid properties (e.g., variable mass flow rate, variable proppant and fluid densities, and viscosity of the fluid) were analyzed, while maintaining outside-casing parameters constant. Validation of empirical proppant transport CFD simulation results are compared to experimental test data.The CFD results 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. Understanding the behavior of proppant and achieving more even proppant distribution among perforation clusters can help the industry. The investigation demonstrates that CFD is an effective tool for optimizing proppant distribution among perforation clusters and enhancing production.

Proppant Distribution Prediction between Perforation Clusters Using Fresh Water in a Horizontal Wellbore

“…The study was conducted on a 4-in., 100-foot-long horizontal wellbore with three perforation clusters separated by 15-feet. Bokane et al 2 used CFD to numerically model this study. Several numerical cases were simulated by varying the viscosity of the carrier fluid, the slurry injection rate, and the proppant.…”

A model for proppant dynamics in a perforated wellbore

“…With regard to large scale modeling, one of the relatively early studies [15] performed a series of yard tests to investigate the effect of various parameters on proppant distribution between perforations. Later, the study [16] used CFD simulations to model the large scale tests from [15]. The study [17] utilized a CFD model to analyze the proppant distribution within a hydraulic fracturing stage for realistic field parameters and accounting for perforation erosion.…”

Experimental Investigation of the Impact of Particle Size on Its Distribution within a Horizontal Wellbore

“…An optimal proppant distribution increases the likelihood of maximizing production from unconventional shale gas and oil resources. Therefore, several investigations were conducted to understand the proppant distribution behavior numerically using computational fluid dynamics (CFD). − …”