Xiao Zhihua, Zhong Ningning, Huang Zhilong, et al. A study on hydrocarbon pooling conditions in tight sandstones through simulated experiments[J]. 2008, 29(6): 721-725.DOI: 10.11743/ogg20080603.
A study on critical geological conditions for oil pooling in inversed oil/water distribution in tight sands is carried out through various serial physical simulated experiments. The result shows that
for crude with density of about 0.8g/cm
3
a stable inversed oiL/water distribution may occur when the pore throat radius of different capillarity glass tubes made of the same material are 1.8 mm or the grain diameters in sand-column are smaller than 0.35-0.40mm. The phenomenon is thought to be related with the equilibrium between buoyancy (flota-tion) and capillary force and oil density plays a more important role than that of the interfacial tension in the formation of this inversed oil/water distribution. Therefore
it is suggested that the formation of oil pools with inversed water/oil distribution in tight sandstone is subject to the pore radius of reservoir sands and its relationship wish the density of crude oil.