Отправлено: 05.06.19 10:26. Заголовок: Experimental investigation on the effect of wettability on rock-electricity response in sandstone

Experimental investigation on the effect of wettability on rock-electricity response in sandstone reservoirs
Y Han, C Zhou, J Yu, C Li, F Hu, H Xu, C Yuan - Fuel, 2019 - Elsevier

A B S T R A C T
To fundamentally study the effect of wettability on sandstone conductivity, a series of experiments, including
rock-electricity, nuclear magnetic resonance (NMR) and wettability tests, were conducted systematically on
high- and low-permeability sandstone samples.
The results show that wettability had different influence on the
conductivity laws of high- and low-permeability sandstones, which was mainly caused by the complex combination of pore and pore-throat.

The conductivity laws of oil-wet high-permeability sandstones, which mainly developed large pores and coarse throats with small water-wet bound space, were mainly followed the oil-wet conduction law.
However, the preferentially oil-wet low-permeability sandstones primarily developed middleto-small pores and micro throats with large water-wet bound space. Hence, the large amount of bound space
followed the water-wet conduction law, while the relatively large pore with oil-wet property was dominated by
oil-wet conduction law.

Consequently, the conductivity of oil-wet sandstones with low-permeability was cocontrolled by the wettability and pore structure.
The study can result in a quite different saturation under the same resistivity compared with the Archie ’s law, and provide a meaningful guidance for establishing oil-saturation calculation model, which can improve the oil-layer identification accuracy and eventually enhance the oil-wet reservoir recovery.