CHARACTERIZATION OF INTERACTION BETWEEN OIL/BRINE/ROCK UNDER DIFFERENT ION CONDITIONS BY LOW FIELD SOLID-STATE NMR

摘要

For the foreseeable future，water flooding will still remain the most economical and the most efficient way for oil field development and production. Apart from the conventional purpose of water flooding,which is to supplement energy into reservoirs and to support formation pressure,how to extend the function of water flooding is a key to enhance oil recovery while keeping the cost low enough. Currently,ions tuning water flooding(ITWF),with its function to adjust the ion strengths amongst ions of reservoir oil,clay minerals and injected fluid,rises as a hot-spot add-on that helps detach the crude oil from surfaces of clay minerals,hence enhances both micro and macro oil displacement efficiency. Quantitative investigation and evaluation of the microscopic mechanism of ITWF on oil/water/mineral is the key to the technical breakthrough. In this work,we suggested to use low field solid state NMR to evaluate the interaction between model oil compounds and inorganic rock interface under different ions tuning water. The fully refocused FID changed according to different water and ion used. Adding certain amount water weaken the interaction between model oil compounds and inorganic rock interface. However,ions strengthen the interaction between model oil compounds and inorganic rock interface,which played a negative role. The results could well guide our further application of ITWF.