Quartz exists in three main forms in shales: biogenic quartz (BQ), detrital quartz (DQ), and clay-transformed quartz (CTQ), which affect the fracability of shale gas reservoirs.
The study analyzes shale samples from the Weiyuan gas field, focusing on the genetic origins and relative percentages of these quartz types across different graptolite zones, revealing variations in their mechanical properties and behavior.
Results highlight that the LM1-LM3 zones, rich in BQ, have the best conditions for hydraulic fracturing, while DQ and CTQ show different impacts on mechanical properties like Young's modulus and Poisson's ratio.