Laboratory characterization of hydraulic properties of sandstones using induced polarization and nuclear magnetic resonance for a joint permeability model

Abstract:

The permeability of sandstones can be modeled using the Katz and Thompson (KT) model which relates permeability to a characteristic hydraulic length scale, typically measured by mercury injection, and the electrically interconnected porosity. In situ estimation of these hydraulic parameters remains a challenge in hydrogeology; emerging geophysical technologies may help to solve this problem. Induced polarization (IP) and nuclear magnetic resonance (NMR) are two geophysical methods shown to be sensitive to physical properties of the pore space that control fluid flow, such as the pore size distribution. Using laboratory data collected on sandstone cores with a diverse range of properties, we demonstrate that our measured NMR parameters best predict the characteristic hydraulic length scale of the KT model, while the IP data can be used to improve estimates of the true formation factor. We incorporate these estimated hydraulic parameters into a KT model to derive an IP-NMR permeability model that compares favorably to permeability estimates from the KT model using mercury injection measurements. Furthermore, the resulting model uses parameters that are potentially measureable in the field; future work will focus on implementing the model at the field scale.