Selecting key parameters of the green pellets and lightweight ceramic proppants for enhanced shale gas exploitation

Ceramic proppants are classified as propping agents commonly used for the shale gas industry. Fractures created in shale deposits due to high fluid pressure (hydraulic fracturing) have to be propped allowing unconventional gas migration to a borehole. Ceramic granules located in the newly created fissures act as a prop so that the shale gas can flow up the well. It occurs if the proppants can resist the huge forces of the closing fractures at high temperature. Due to these strict geological conditions and processing requirements the proppants have to be characterized by proper physico- mechanical properties. The aim of this research was to study, compare and select the ceramic proppants characterized by the most appropriate parameters. The investigation relates to the industrial granules obtained by the mechanical granulation method and afterwards sintered which were confronted and analyzed. Utility of the proppants was estimated basing on bulk density and roundness coefficient. Structure, morphology and chemical composition of the samples were determined by the Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS). The sintered proppants were also characterized with X-Ray Tomography, turbidity and solubility in acid additionally. The crucial parameter as mechanical strength was established during the propping samples subjection to the crush tests. The obtained outcomes prove that chemical composition, pores distribution, grain size and mechanical strength influence the integrity of created fractures and therefore the extraction of the unconventional gas out of the well. (C) 2016, PROSTR (Procedia Structural Integrity) Hosting by Elsevier Ltd. All rights reserved.