Chapter 5: Proppants and Fracture Conductivity Available to Purchase

This chapter discusses propping agents (proppants) and their role in the hydraulic fracturing process. It reviews the development of proppants from the initial application to present-day proppant products and describes the role of proppants in affecting the performance of hydraulically fractured wells. The chapter also addresses specifically the role of fracture conductivity in determining the outcomes of fracture stimulation, discusses the measurement of proppant pack permeability and conductivity in the laboratory, and explores factors that can severely limit these properties in the downhole environment.

Proppants are essential components of hydraulic fracturing. Without using proppants in the fracturing process, the fractures that are created will essentially close, which will severely limit the intended well performance benefit (Howard and Fast 1970). The types and volumes of proppants used in a fracture stimulation vary widely from high-strength large-mesh ceramic proppants in deepwater frac packs and high-permeability conventional reservoirs to very-fine-mesh natural sand products commonly used in onshore unconventional well developments in North America. The challenge in choosing the right proppant lies in an understanding of the reservoir properties and the expected fracture geometry to be created, and then matching that understanding to a selection of proppant properties and performance. Ultimately, the decision is an economic one—a balance of the cost of application of a particular type and volume of proppant against the value returned.