Frac Sand & Proppant Types

Natural frac sand is found naturally in the Earth’s crust and is composed primarily of Silicon Dioxide (SiO2). It is the same sand that is used to make glass, industrial castings, filters, and sand castles at the beach. For natural sand to qualify as frac sand and be used in hydraulic fracturing, it must meet certain strict specifications. These specifications are API RP 56 and/or ISO 13503-2. These two certifications measure properties of the sand such as grain size, roundness, sphericity, specific gravity, acid solubility, and crush resistance. It turns out that most beach sand does not make good, quality frac sand.


Natural frac sand has a crush resistance between 4,000-10,000 psi depending on the gradation or size (20/40, 30/50, 70/140 etc.). A crush resistance with that range of psi rating is adequate for shallow to intermediate depth wells of 2,000-10,000 feet. Anything deeper than 10,000 feet will require an analysis of using a higher crush prop such as resin coated or ceramic.


Resin coated frac sand is natural frac sand that has undergone a process to produce a resin coating encapsulating each individual grain to make it stronger. This is done to produce a proppant that can be used in deeper wells where otherwise the natural frac sand would have failed.