(52h) CFD Modeling of Proppant Distribution in a Multiply-Perforated Horizontal Pipe for Applications in Hydraulic Fracturing

Proppant distribution in a hydraulically stimulated horizontal well has important implications since it can significantly influence the production efficiency of an unconventional well. It has been known that a fractured reservoir with more evenly distributed proppants can have higher production over time, therefore it is important to understand the interplay between fluid and proppant distributions, and how to better promote the desired distribution of proppants.

In this work the proppant flow distribution is studied using computational fluid dynamics (CFD) with proppant particles individually traced to model the interactions between proppants and the carrier fluid (Snider, 2001; Tsai et al., 2012). The flow field is solved using large eddy simulation (LES) with the interactions between proppants and carrier fluid resolved by adopting a well-established drag law (Wen and Yu, 1966) and a solid pressure model (Harris and Crighton, 1994) to account for the fluid-particle and inter-particle forces, respectively. By simulating known flow and proppant distributions in a multiply-perforated horizontal pipe (Crespo et. al.,2013), the driving mechanism for proppant distribution can be studied in detail.

Since proppants and carrier fluid are modeled interactively, investigation of proppant distribution's sensitivity on carrier fluid viscosity and proppant density can be carried out with high certainty. Issues regarding the validity of using acoustic data to interpret proppant distribution will also be discussed.

This is also a typical slurry flow problem often encountered in many chemical and refining processes, including the transport of polymer pellets, pneumatic transport of powdery particles, fluidized bed, etc. However, there are surprisingly few CFD investigations done for slurry flows in horizontal pipes. A literature survey shows that credible CFD models capable of predicting the pressure drop and solid distribution across a wide range of flow regimes are non-existent. This work attempts to tackle some of these questions by starting with proppant flows where monetary impact can be significant and hopefully can be extended to other areas of interests.

References,

Crespo, F., N. K. Aven, J. Cortez, M. Y. Soliman, A. Bokane, S. Jain and Y. Desphande, “Proppant distribution in multistage hydraulic fractured wells: A large scale inside-casing investigation,” SPE Paper #163856, 2013.

Harris, S. E. and D. G. Crighton, “Solitons, solitary waves, and voidage disturbances in gas-fluidized beds,” J. Fluid Mech. 266, 243-276, 1994.

Snider, D., “An incompressible three-dimensional multiphase particle-in-cell model for dense particle flows,” J. of Comp. Phys. 170, 523-549, 2001.

Tsai, K., E. Fonseca, S. Degaleesan and E. Lake, “Advanced computational modeling of proppant settling in water fractures for shale gas production,” SPE J. 18, 50-56, 2013.

Wen, C. Y. and Y. H. Yu, “Mechanics of fluidization,” Chem. Eng. Prog. Symp Ser. 62, 100-110, 1966.