Micro Pore Structure Characteristics Of Unconventional Tight Oil Sandstone Reservoir And Water Displacement Efficiency

In recent years,with the support of technologies,including horizontal wells,the volumetric fracturing and the factory-like operation,the domestic tight sandstone reservoir has been high effectively exploited but difficult points still exist that study of the pore structure characteristics and oil displacement efficiency are critical questions.Therefore,this paper will complete a research about pore structure characteristics and water displacement efficiency through some theoretical approaches and a series of experiments,such as regression analysis method,grey incidence analysis,grey cluster analysis,mercury intrusion porosimetry,oil-water relative permeability experiment and water-oil displacement experiment.Based on mercury intrusion porosimetry,grey incidence analysis and grey cluster analysis,some conclusions can be drawn as following: As a part of pore structure characteristic parameters,structure coefficient has the best correlation with porosity and permeability.The new factor and model,the grey pore structure comprehensive factor and the grey pore structure comprehensive evaluation model,is constructed.According to the results of the study of pore structure and the data of oil-water relative permeability experiment and water-oil displacement experiment,the study on water displacement efficiency can be finished.The consequence show that although many influence factors including the injection volume,reservoir physical properties and pore structure characteristics embody a certain correlation with water displacement efficiency,all elements couldn't do clearly.In addition,comparing the grey pore structure comprehensive factor and the parameter calculated by the reciprocal of variation coefficient multiplying structure coefficient,the former has better correlation with water displacement efficiency.