What are the different types of proppants?

Today, proppant materials can be grouped into three main categories: rounded silica sand, resin-coated sands, and synthetic ceramic materials (Fig. 3). The most commonly used base materials are sand, ceramic, and sintered bauxite. Evaluations of proppant performance within formations have been improved over the past 30 years, with specific quality-control procedures developed by the American Petroleum Institute (API) and the International Standards Organization (ISO). Proppant selection, including type, size, and shape, is a critical element in stimulation design. These proppants must withstand high temperatures, pressures, and the corrosive environment present in the formation. If a proppant fails under the stress, it disintegrates, reducing the permeability of the propped fracture.

Availability and cost are the most desirable attributes of proppants, but the physical qualities of both natural (e.g. sand grains) and man-made (e.g. resin-coated sand and ceramic) proppants are equally crucial. The structural properties of proppants are assessed using specific criteria, which include:

• Conductivity: the amount of flow that the proppant will allow.
• Acid Solubility: tests of solubility in acid to indicate contaminants and determine performance underground.
• Shape: the degree to which a proppant grain is round or spherical, impacting its interaction with fracking fluids and production efficiency.
• Crush resistance: the ability to withstand the stress of high bottom-hole pressures.
• Solubility: the proppant's resistance to dissolving within a substance.
• Turbidity: measures the absence of impurities such as clay or silt within the proppant material.

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Fig. 2 Representation of proppant agents settling into the fractures

Fig. 3 Cost-efficiency “pyramid” of proppant types

Fig. 4 Sample of artificial glass proppant produced from waste bottles

Fig. 5 Samples of proppants with different density

Fig. 6 Multifunction ceramic proppants coated with bacterial biofilm

Fig. 7 Krumbein-Sloss chart

Fig. 8 Refiguration of proppant shapes

Fig. 9 Chart resuming the basic proppant selection factors

The original version of this article was created by Francesco Gerali, 2020 Elizabeth & Emerson Pugh Scholar in Residence at the IEEE History Center

It is recommended this article be cited as:

F. Gerali (2020). Proppants, Engineering and Technology History Wiki. [Online] Available: https://ethw.org/Proppants