Abstract
Unconventional sandstone reservoirs with ultralow permeability (1 mD < Kair < 10 mD, where Kair represents the permeability in air) and superlow permeability (0.1 mD < Kair < 1 mD) in China are widely distributed in major basins and have significant economic potential. (Here, D is a permeability unit: 1D = 1000mD = 1 μm2.) A comparative study has been performed here on three Upper Triassic sandstone reservoirs with superlow permeability in the southern Ordos Basin to understand the characteristics of each reservoir, the differences in reservoir porosity and permeability, and their causes. The study shows that pore type is the main factor that controls the physical property of nonfractured, superlow permeability sandstone reservoirs in the area of study. The main pore type observed in all three reservoirs is dissolution-enhanced intergranular, which comprises a maximum of 70% of the total porosity. Remnant intergranular and intragranular dissolution pores are also observed in these reservoirs. The pore thr...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have