Abstract: The present invention relates to a method to enhance oil recovery from a hydrocarbon reservoir. One aspect of the invention includes injecting low-salinity water into the reservoir followed by the injection of a surfactant diluted in low-salinity water, and alternating the injections of the low-salinity water and the surfactant diluted in the low-salinity water. A gas is then injected into the reservoir. The invention improves the effectiveness of the surfactant and the gas by reducing the salinity of the reservoir by injecting low-salinity water into the reservoir.

Abstract: The present invention relates to a method to enhance oil recovery from a hydrocarbon reservoir. One aspect of the invention includes injecting high salinity water into the reservoir followed by alternating the injection of low salinity water and gas.

Abstract: The present invention relates to a method to enhance oil recovery from a hydrocarbon reservoir. One aspect of the invention includes injecting low salinity water into the reservoir followed by the injection of a surfactant diluted in low salinity water, and alternating the injections of the low salinity water and the surfactant diluted in the low salinity water. The invention improves the effectiveness of the surfactant by reducing the salinity of the reservoir by injecting low-salinity water into the reservoir.

Abstract: Apparatus and methods of using lasers are provided for spalling and drilling holes into rocks. A rock removal process is provided that utilizes a combination of laser-induced thermal stress and laser induced superheated steam explosions just below the surface of the laser/rock interaction to spall the rock into small fragments that can then be easily removed by a purging flow. Single laser beams of given irradiance spall rock and create holes having diameter and depth approximately equal to the beam spot size. A group of the single laser beams are steered in a controllable manner by an electro-optic laser beam switch to locations on the surface of the rock, creating multiple overlapping spalled holes thereby removing a layer of rock of a desired diameter. Drilling of a deep hole is achieved by spalling consecutive layers with an intermittent feed motion of the laser head perpendicular to the rock surface.