The hydraulic fracturing industry recognizes two primary proppant types: sand and man-made (ceramic) proppants. Selecting the right proppant for a well focuses on the mechanical strength and conductivity of proppants under down hole (application) conditions. Since proppants are generally stable under high temperature, high pressure conditions, their environmental impact on well completion is often considered minimal. However, with recent increases in proppant consumption, mass of proppant used on a well site can now easily reach 6 million pounds. Transportation, storage and handling of such high volumes of any material pose an environmental challenge. This study compares the environmental impact of three different types of proppants: sand, lightweight kaolin clay proppants and intermediate density bauxite proppants, and proposes best practices to minimize risks.
This study first investigates dust generation associated with transportation, handling and storage of proppants. Results show that attrition of all tested proppant types generates dust. Chemistry, morphology and health hazard ratings of crystalline species present in generated dust are compared across variety of proppant types. Best practices for dust control are discussed.
Secondly, study focuses on natural radioactivity of current proppant products and compliance with state waste disposal NORM regulations. Study compares levels of detected natural radioactivity in proppants based on their type, geographic origin and detection method used. Costs associated with waste disposal of these materials are compared for several different states.
Authors: Tihana Fuss (Saint-Gobain Proppants), Jingyu Shi (Saint-Gobain Proppants), Jun MA (Saint-Gobain Research (Shanghai) Co Ltd), Daniel C. Herndon (Saint-Gobain Proppants), Walter T. Stephens (Saint-Gobain Proppants)
Paper Number: SPE-169571-MS