Plug-and-perf is a completion technique commonly used in multistage hydraulic fracturing as an effective method for developing unconventional resources. Fracture performance modeling commonly assumes that fluid and proppant distributes uniformly among all perforations along the length of the wellbore in a plug and perf completion. However, some parameters have been shown to have a great influence on the fluid and proppant distribution, such pump rates, perforation design, reservoir properties, fluid rheology, and proppant characteristics. Crespo et al. (2013) has conducted a limited proppant flow experiment using a 63 foot stage, and three 0.42 inch with zero phased simulated perforations. His work demonstrates proppant does not distribute evenly, but the work is limited to a single perforation scheme.
In this work, Computational Fluid Dynamics (CFD) software has been used to simulate proppant transport and distribution in a single stage of plug-and-perf completion with different perforation phasing. A CFD model is constructed matching the experiments of Crespo et al. (2013) using a one-way coupling method. The validated, base model is then extended by changing perforation phasing and cluster length to investigate proppant distribution in perforation design recommendations presented by Wutherich (2012). Limited-entry perforation pressure drops determined from CFD modeling are compared to the analytical equation to further validate the work. Two-way coupling method was conducted on optimum perforation models identified in the work.
The results of the CFD modeling study indicated that proppant does not distribute evenly among perforations within a single cluster. While 60 phasing may be preferred for well productivity assuming even proppant distribution, CFD modeling demonstrates uneven proppant distribution especially for zero degree rotation. In addition, 60 phasing with 90 degree rotated and 150 degree rotated; and 90 phasing with 135 degree rotated perforations provided more even proppant distribution.
This paper presents CFD modeling of a validation study (Crespo 2013) and extended investigations of proppant transport and distribution in a single stage of plug-and-perf completion with different perforation strategies. Pressure drops at each perforation are discussed and compared with theoretical calculations. The results demonstrate that CFD modeling technique is an effective tool for better understanding and optimizing the fluid and proppant distribution among perforation clusters within fracturing process.