Improving water injectivity and enhancing oil recovery by wettability control using nanopowders

Wettability of porous media plays an important role in effecting multiphase flow, which provides a clue to modify percolating process in porous media. The objective of this work is to study the effects of wettability on fluids flow and its applications in oil fields. Firstly, the effect of wettability on oil recovery was analyzed by experimental data. Secondly, the wettability alteration induced by wettability control agents was studied by experimental approach. Thirdly, a two-phase flow mathematical model considering wettability control by chemical agents is presented. Finally, a numerical simulator considering wettability control was developed and oil field examples were run on the simulator and the percolation behaviors of two-phase flow were predicted. Numerical simulations show that the treatment of increasing water-wetting wettability control agent (IWWCA) leads to 15.38% more in oil recovery than that of normal water displacement. Increasing oil-wetting wettability control agent (IOWCA) improves 60% to 80% more in water injection rates. It was found that the concentration of IWWCA has an obvious effect on oil recovery when IWWCA concentration is less than 0.02. IOWCA treatments of 6 oil-field injection wells show that average water injection capacity increases up to 2.75 times of their initial injection capacity.