It is always the key point in the field of oilfield development to study the oil circulation condition and percolation law in reservoirs.Based on the percolation theory,a three⁃dimensional percolation model is established by numerical simulation method,which can simulate the distribution of cracked joints,percolation laws,percolation thresholds of reservoir rocks and determine whether they are permeable.The results show that when the connectivity probability increases from 0,the total number of clusters increases.When the connectivity probability increases to 0.17,the total number of clusters begins to decreases.When the connectivity probability is small,the percolation probability increases slowly with the increase of the connectivity probability.When the connectivity probability exceeds the first critical value,the growth rate of the percolation probability suddenly increases.When the connectivity probability exceeds the second critical value,the percolation probability begins to slowly increase again and eventually approaches 1.The seepage cluster can accurately determine whether the porous medium is permeable and accurately capture the percolation threshold.The size of the percolation threshold is related to the size and shape of the medium.There is no obvious regularity between the maximum cluster size and the average cluster size,the maximum cluster size and the total number of clusters.It is concluded that this three⁃dimensional percolation model can simulate the long⁃range coupling mutation caused by the change of connectivity probability in porous media,which can be used to simulate the permeability and percolation law of rock.

A reactor with a volume of 50 mL was used as a container to carry out hydrothermal liquefaction of enteromorpha and solvent under high temperature and high pressure conditions.The purpose of this experiment was to investigate the effects of various reaction conditions on the distribution of hydrothermal liquefaction products and the composition of bio⁃oil products,such as reaction time,reaction temperature,liquid⁃to⁃liquid ratio and ethanol ratio in solvent.The experimental results show that the reaction time is 45 minutes,the reaction temperature is 300 ℃,the liquid to material ratio is 40∶4.0,and the proportion of ethanol in the solvent is 50%,which is the most suitable reaction condition for the hydrothermal liquefaction of enteromorpha,and the yield of the obtained bio⁃oil is 45%.In addition,by GC⁃MS analysis of bio⁃oil components,the addition of ethanol in the solvent caused the alcoholysis reaction of the amide compound in the bio⁃oil product which increased the content of the ester compound and improve the quality of bio⁃oil.