Crush resistance and size distribution are two measurements to select a proppant. While standard sieve analysis provides a good quantitative value for crush resistance, detailed size measurements can provide more understanding of proppant failure and the alteration of size distribution under load. The variance in proppant crush resistance is often larger than the typically reported accuracy of ±0.1%. In many cases, specimen handling and material retention upon sieves makes a real contribution towards measurement error.
This paper documents the variation in crush resistance measurements for proppants of similar size and size distribution at constant stress. Optical measurement of the size distribution can reveal more information about proppant failure under load. The paper discusses the sensitivity of the measurement with respect to manual versus automatic load application, loading rate, cell size, and specimen mass. The accuracy and precision of the test, along with the minimum sample size, are reported. The relationship between size distribution and crush resistance for different proppant materials is also presented.
The results of this paper address expanding the technical evaluation of proppants using new tools and analysis methods to provide a greater understanding of the crush resistance measurement. Operators will be able to select an appropriate proppant for their application with a practical understanding of measurement variation.
Authors: Walter T. Stephens (Saint-Gobain Proppants), Stephen K. Schubarth (Schubarth Inc.), Deborah I. Rivera (Saint-Gobain Proppants), E. Michael Snyder (Saint-Gobain Proppants), Daniel Clare Herndon (Saint-Gobain Proppants)
Paper Number: SPE-102645-MS