Impact of Pyrite Oxidation on the Pore-Structure Characteristics of Shale Reservoir Rocks under the Interaction of Fracturing Fluid
Zepeng Sun, Yue Ni, Yuandong Wu, Yong Lei
Abstract
adsorption was performed to quantify the pore structure. The results showed that the pyrite oxidation induced the dissolution of both the pyrite and calcite and generated many dissolution pores for the pyrite-rich shale after slickwater treatment. The mineral dissolution led to an increase in the number of mesopores, enlarged the total specific surface area (TSSA) and total pore volume (TPV), and strengthened the pore-structure complexity. On the other hand, the pyrite-poor shale only experienced clay swelling after slickwater treatment. Its pore surface roughness and pore-structure complexity degraded with the loss of nanopores and the reductions in TSSA and TPV. The results of this study enhance the understanding of the impact of pyrite oxidation on the pore structure and provide new insight into the optimization of fracturing operation conditions based on shale's mineral composition characteristics.