Imbibition runs at different overburden pressures have been performed on a SFE2-8707 sample from the Travis Peak formation (slot and solution pore type), with an approximate porosity of 7% and gas permeability of 22 to 37 μd, using our physical model. The experiment continued for several days untill the water flow rate reached the steady state values. The single phase water flow experiments were performed at several inlet and overburden pressures, following the imbibition runs.
The results from imbibition and single phase water flow experiments showed that under different overburden pressures, due to the porous structure changes, considerable amounts of pore closing and opening occurred which resulted in an overall increase in permeability of the sample. However from single phase gas flow experiments an overall decrease in permeability of the sample was observed. Furthermore the single phase transient experiments compared well with steady state runs. This proves the reliability of transient runs which results in significant saving in time and expense for core analysis of tight core samples.