Assessing portable air permeameter in bioturbated sedimentary rocks

The characterization of permeability in bioturbated sedimentary rocks is essential for assessing reservoir quality, as some trace fossils can either enhance or reduce permeability. However, the heterogeneity introduced by structures such as Ophiomorpha makes conventional evaluation techniques less effective. This study examines the feasibility of using a portable air permeameter (TinyPerm3) to estimate point permeability values in bioturbated sedimentary rocks, with a focus on its practical applicability in reservoir characterization. We first compare conventional laboratory gas-permeability measurements with those obtained using the portable device on non-bioturbated rocks with different textures. We then test TinyPerm3 on rough and smooth surfaces, and on dry, humid, and wet samples, focusing on rocks containing Ophiomorpha . Results are compared with laboratory data to assess accuracy under varying conditions. Findings show that TinyPerm3 provides reliable relative permeability values, although absolute values tend to be overestimated, especially on rough surfaces where improper sealing affects measurements. Controlled simulations indicate that dust and moisture can artificially lower permeability by clogging the pore system, while clean, dry, or slightly humid surfaces yield more accurate results. In Ophiomorpha -bioturbated samples, burrow fills generally show higher permeability than the host rock, except on weathered surfaces where surface processes likely obstruct porosity. This study provides new insights into how bioturbation structures influence permeability heterogeneity and quantifies the limitations of portable permeameters in such complex media, while also offering practical guidelines for obtaining reliable permeability data in both field and laboratory settings. Overall, portable air permeameters are recommended for assessing relative permeability in bioturbated rocks, provided measurements are taken on flat, clean, and dry surfaces. This study supports the use of portable air permeameters as a practical and cost-effective alternative for permeability assessment in heterogeneous reservoirs, contributing to improved reservoir quality evaluation and more informed decision-making in exploration and production.