1,3-Dialkyl glyceryl ethers derivatives as surfactants for enhanced oil recovery in high salinity and high temperature reservoir conditions

The sulfobetaine and sulfonate surfactants derived from 1,3-dialkyl glyceryl ethers were examined as surfactants for enhanced oil recovery free of alkali in high salinity and high temperature reservoir conditions. The surfactants containing polyoxypropylene-polyoxyethylene chain are relatively hydrophilic and the sulfobetaines derived from symmetric and asymmetric 1,3-dialkyl glyceryl ethers are relatively hydrophobic. The binary mixtures at appropriate molar fraction ratio are well soluble in connate water with a total salinity as high as 20,000 mg/L including 800 mg/L Ca 2+ and 40 mg/L Mg 2+ , and can reduce the interfacial tension between the connate water and crude oil to 10 −3 ∼10 -4 mN/m magnitude at and beyond 60 °C in a wide total concentration range, 0.1∼5 mM. In addition, the formulations show good resistance to the adsorption by quartz sands and prefer to form crude oil-in-connate water (O/W) emulsions.