摘要
Increasing the number of depleted reservoirs and global demand for energy have left us with low alternative but to use new ways to extract more hydrocarbon.Amongst different material used for tertiary oil recovery,surfactant injection has proved very promising solutions,such as interfacial tension reduction and wettability alteration.Without any harm to the environment and meanwhile being economically feasible,natural surfactants have been attracted researchers in recent years.Cedr extraction which is produced from Zizyphus Spina Christi leaves has shown some beneficial characteristics like IFT reduction and wettability alteration.However,the amount of IFT reduction is not considerable,so we decided to augment its effectiveness by adding two different nanoparticles.In this investigation,three concentrations(0.01,0.05 and 0.1 wt%)of both graphene oxide(GO)nanosheet and GO/TiO_(2) nanocomposite was added to Cedr extraction solution to study their potential on IFT reduction and improving the ultimate oil recovery.The concentration of 0.05 wt percent showed the lowest IFT in both solutions.At this concentration,the IFT of GO/TiO_(2)-augmented solution and GO-augmented solution were measured of 10.5 and 12.3 mN/m,respectively.While the bare Cedr solution showed 23.8 mN/m at its critical micelle concentration.The coreflooding tests were also performed at the aforementioned concentrations.Final oil recovery reached to 65%of original oil volume in GO/TiO_(2)-augmented solution,compared to 56% in GO-augmented solution case and 40%in bare Cedr solution case.Scanning Electron Microscopy images were also taken from the rock samples exposed to nanofluids to investigate any severe harm to the permeability.Images showed low tendency of both particles to adsorb on rock surface and plug large pores.
