12 of the pressure vessel using pressure fittings 18 and 21 additional fittings and tubing were used to connect the inlet of the slim tube 11 to a pressure pump 13 and a feed reservoir 14 additional fittings and tubing connected the inlet of the slim tube to an absolute pressure transducer 20 and the high pressure side of a differential pressure transducer 19 fittings and tubing connected the outlet of the slim tube 12 to the low pressure side of a differential pressure transducer 19 and to a back pressure regulator 16 the signals from the differential pressure and the absolute pressure transducer were ported to a computer and the pressure readings were monitored and periodically recorded the pressure vessel 10 around the slim tube was filled with water through a water port 15 this water was then slowly pressurized with air 17 to a pressure of about 105 per square inch psi 0 72 mega pascal while brine 1 from the feed reservoir 14 table 1 flowed through the slim tube and left the slim tube through the back pressure regulator 16 this operation was performed such that the pressure in the slim tube was always 5 to 20 psi 0 034 0 137 mega pascal below the pressure in the pressure vessel 10 once the pressure inside and outside the slim tube was established one pore volume of the crude oil from an oil reservoir of the milne point unit of the alaskan north slope was pumped into the slim tube this process was performed in several hours h once the crude oil had saturated the core sand in the slim tube and was observed in.