Tight sandstone reservoirs have become important areas
for unconventional
reservoir development, and their pore network is a key feature for
identifying tight sandstone, which affects fluid migration path and
reservoir development efficiency. However, the connectivity characteristics
of the pore network at different scales have remained unclear owing
to the numerous pores and uneven pore shape. Here, using pore size
distributions from many hundreds of tight sandstone samples and subsequent
topological data analysis, we construct the topological structure
of the pore network in the Yanchang Formation tight sandstone of the
Ordos Basin in China and visualize the topological characteristics
of the pore network with distances. We show that there are three connected
groups within the pore structure of the tight sandstone. The topology
of the pore network resides on a trident ring manifold, suggesting
that the pore network in the tight sandstone encompasses three obvious
dominant connection paths. One prominent bar on the H0 dimension
in the barcode indicates a two-point connection from nanoscale to
microscale in the pore network. Three prominent bars with varying
durations on the H1 dimension indicate the presence of
three separate multipoint connections within a limited extent in the
pore network. Connectivity of combined pores is good and controlled
by the topological structure of the pore network. This demonstration
of pore connections on a trident ring manifold provides a population-level
visualization of the pore network in the tight sandstone.