Optimization of the Proppant Manufacturing Process for Improved Mechanical Integrity and Cost Efficiency

Abstract

Hydraulic fracturing is one of the most critical well stimulation techniques in the petroleum industry, relying on proppants to maintain fracture conductivity against reservoir closure stresses. The mechanical integrity and production cost of proppants are decisive factors in the economic viability of any stimulation operation. This thesis addresses the optimization of ceramic proppant manufacturing through the integration of theoretical fundamentals and experimental investigation, with the dual objective of enhancing mechanical performance while minimizing production costs through locally sourced raw materials and energy-efficient processing. The theoretical framework covers the full scope of proppant technology — from the early history of silica sand proppants through the evolution of resin-coated and ceramic types — and provides a comprehensive treatment of hydraulic fracturing mechanics, including in-situ stress regimes, fracture propagation models (PKN, KGD, and radial geometries), fracturing fluid systems, and the complete operational chronology from well preparation through post-fracture evaluation. Experimentally, calcium oxide was first synthesized in-house from limestone (CaCO₃) via thermal decomposition at 1000 °C, achieving a mean conversion yield of 85.40%. A ceramic formulation based on bauxite, kaolin, silica, and alumina — with minor additions of MgO, CaO, TiO₂, and Fe₂O₃ — was processed through dry ball milling, PVA binder-assisted slurry preparation, and granulation by a modified pan-rolling method as a low-cost alternative to industrial spray drying. The green granules were sintered at 1100 °C for seven hours. All raw materials were verified by X-ray diffraction (XRD) prior to processing, confirming phase purity and identifying partial hydration in MgO and CaO precursors, which was shown to have no adverse effect on the final product. Characterization of the sintered proppant according to API RP-19C and ISO 13503-2 yielded an apparent specific gravity of 2.751 — placing the material within the commercially viable lightweight ceramic (LWC) category — and an acid solubility of 3.33% under aggressive test conditions (7.5% HCl, 80 °C, 48 hours), well below the 7% API ceramic limit. XRD of the sintered product confirmed the formation of mullite and sillimanite as the dominant crystalline phases, validating the sintering chemistry. However, bulk density measurements (1.112 g·cm⁻³) and apparent porosity (59.6%) revealed significant inter-granular packing deficiency attributable to the irregular morphology produced by manual pan-rolling, rather than to any deficiency in the chemical formulation or sintering temperature. These findings confirm that the mineralogical design and thermal processing parameters are sound, while pan-rolling granulation constitutes the sole technological bottleneck. Transition to an industrial spray- drying or disc-pelletization unit is identified as the most cost-effective path to achieving commercial-grade packing density