There is disclosed a method for enhancing recovery of crude oil from a porous subterranean carbonate formation of which the pore spaces contain crude oil and connate water, the method comprising determining an ionic strength of the connate water; and injecting an aqueous displacement fluid having a lower ionic strength than the connate water into the formation. The method and apparatus of the present invention uses slide trays that have receptacles for at least one specimen slide and an associated reagent pack. As players move, virtual tails are generated behind each player, and their locations are determined and geocast, via a wireless geographic broadcast protocol, to all players of the geogame. The structure allows for area efficiency by allowing placement of active silicon circuitry under the microphone. When the removable polarizing substrate is placed in front of the strips in a certain orientation, autostereoscopic imaging is viewed by the observer, and when this polarizing substrate is removed, 2D imaging is viewed. At least one of these holes in the plate has an internal jacket surface that tapers towards the underside, while the internal jacket surface has N\u22673 recesses which extend radially away from the axis of the hole.