Method and apparatus for determining the wettability of an earth formation

摘要

A method and apparatus for determining the wettability of an earth formation wherein a fluid sample from the wall of a borehole penetrating said formation is extracted then reinjected into the wall of the formation. A pressure versus time curve is generated throughout the test from which the wettability of the formation is determined by comparing how much the injection pressure varies from the static pressure to how much the extraction pressure varies from the static pressure. A wettability index can also be determined from the areas under the curve.