Experimental study on percolation backbone of secondary migration of crude oil

The experimental studies of the continual secondary migration of crude oil have been carried out 2-dimentionally using the Hele-Shaw model.The percolation backbone of the secondary migration of crude oil has been verified by changing the color of injected oil after the formation of initial migration pathway.Buoyancy and capillary force changes after the formation of initial migration pathway are the main reason for percolation backbone.The size and fractal dimension of the backbone are smaller than those of the corresponding initial migration pathway.The backbone limits the losses of oil during secondary migration and accelerates the process,so it enhances the secondary oil migration efficiency.