Spontaneous Imbibition Studies of Australian Reservoir Rocks with NeutronRadiography

摘要

Spontaneous imbibition experiments were carried out on threerncore samples from the Mardie Greensand and one core samplernof Barrow Group sandstone from the Australian North WestrnShelf. Water uptake into the samples, which were initially airsaturated,rnwas measured by dynamic neutron radiography. Thernobserved data were interpreted by (1) the linear diffusionequationrnapproximation for fluid flow and (2) the Li andrnHorne model. Both these models were consistent with thernobserved data, and have similar consequences. The linearrndiffusion-equation model suggests that a constant diffusionrnparameter, Dw, can adequately describe the observedrnspontaneous imbibition of water into these samples, underrnambient temperature and pressure, throughout most of thernimbibition process. The Li and Horne model suggests that (1)rnthe effective water permeability of the sample and (2) waterrnpermeability times the capillary pressure gradient within thernsample are approximately constant through most of thernimbibition process, during these experiments. The combinedrnconclusion of these interpretational methods implies that thernwater permeability and the capillary pressure-water saturationrngradient in these samples are constant throughout most of thernimbibition process, under ambient temperature and pressurernconditions.