The results of measurements of the physical properties of the typical oilsands mined in Higashiyama oilfield are as follows.
a. Permeabi ity, 2500 millidarcys; porosity, 30 percent b. Permeability, 600 millidarcys; porosity, 25 percent The oil content of these depleted sands shows 5 percent by volume in the richer parts and 2 percent by volume in the poorer parts. Flow of oil in the reservoir after exploitation has been effected only by gas energy; the shale beds and the small faults have not interrupted the flow of oil in the reservoirs.
The recovery of oil by the pumping wells reduced the percentage by volume or oil in the sands to 2.8 perent; secondary recovery by means of the gallerie drainage in the oilsands further reduced this percentage to 2.0 percent.
