The Research Of Microscopic Remaining Oil On The Basis Of Displacement Experiment And Digital Core

The research of microscopic remaining oil on the basis of displacement experiment and digital core is based on micro-model manufacturing and microscopic remaining oil displacement experiment.Combined with three-dimensional digital cores obtained by X-ray computed tomography and analysis of pore network extraction,microscopic displacement mechanism and remaining oil entrapment mechanism are utilized to predict the distribution of microscopic remaining oil.On the basis of pore network,micro-model is made of glass and sculpted by laser,which is convenient to be observed and recorded and is capable of conducting experiment under the circumstance of high temperature and high pressure to explore the microscopic displacement and remaining oil entrapment mechanism.Samples are carefully selected and through a series of steps including two dimension to three dimension reconstruction,sub-volume extraction,filtering,segmentation,opening,skeletonization,the pore network can be extracted and analyzed.Experiment simulation and numerical modeling are combined to promote the accuracy and reliability.Tazhong 402 reservoir is in the extra-high water-cut stage,whose characteristics are summarized as “five high and one low”,namely,high water-cut,high recovery level,high temperature,high degree of mineralization and low heterogeneity.After a long period of recovery,the pore network,grains and minerals are experiencing transformation,which leads to the complicated distribution patterns of microscopic remaining oil.Therefore,microscopic displacement experiments are conducted and X-ray computed tomography is utilized to reveal the microscopic displacement and remaining oil entrapment mechanism,thus to predict the distribution of remaining oil,providing evidence and reliability of further tertiary recovery.