Harsh Environmental Effects on Low Density Fly Ash Proppants

Abstract Proppants are essential components in hydraulic fracturing for reservoir stimulation, ensuring that fractures maintain conductivity. In high-pressure or harsh environments, high-strength, durable proppants are typically used. However, these proppants are expensive and require costly fracture fluids. This research focuses on developing a new type of proppant that is ultra lightweight, durabile, resistant to corrosion and erosion, and economical. Fly ash, a by-product of various combustion processes, particularly from coal plants, was used to create this new proppant. Fly ash-based proppant formulated is durable, environmentally friendly, buoyant, and cost-effective. To develop the fly ash-based proppant, an alkaline solution was used as an activator and binder. The proppant samples were tested under high temperature and pressure, as well as in acidic, alkaline, saline, and crude oil environments to evaluate their durability. Density was also assessed to determine the buoyancy of the proppant, which affects the fracturing fluid selection. The mix designs included weight ratios of 20%, 22%, and 25% binder, with a fixed 25% water content in all mix designs. After environmental testing, the B20W25 mix design demonstrated satisfactory results across all tests, showing minor erosion and deterioration. Conversely, the B25W25 mix did not withstand the more aggressive environmental conditions and had lower-than-required compressive strength. The density of the three mix designs ranged from 1.33 to 1.35 g/cm3, being categorized as ultra lightweight proppants, making them lighter than sand and thus highly buoyant.