As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous f...As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous flow characteristics,the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models' well pattern adaptability.Through experiments,the models' pressure distribution is measured and on which basis,the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region,non-linear porous flow region,and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve.The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability,while the worst is inverted nine-spot equilateral well pattern.With the increase of drawdown pressure,dead oil region decreases,pressure sweep efficiency and deliverability index increase; meantime,the deliverability index of rectangular well pattern has much more rational increase.Under the same drawdown pressure,the rectangular well pattern has the largest pressure sweep efficiency.展开更多
Juice extraction from chopped sweet sorghum is an example of flow through porous media. Darcy’s law is often used to express this type of phenomenon. However, using Darcy’s law to construct a mathematical model to p...Juice extraction from chopped sweet sorghum is an example of flow through porous media. Darcy’s law is often used to express this type of phenomenon. However, using Darcy’s law to construct a mathematical model to predict juice extraction from chopped sweet sorghum is difficult, because the volume of the porous media changes during the pressing operations. A mathematical model was developed from fundamental analysis to predict the juice extraction ratio of chopped sweet sorghum, and experiments were conducted to verify the model. An experimental piston-cylinder assembly was developed to conduct the validation experiments. The parameters in the developed model were estimated by using non-linear regression analysis from the experimental data. Plots of the mathematical model agreed well with experimental data. R^2（coefficient of determination） values for all the regressions studied were higher than 0.99. Results showed that the juice extraction ratio of chopped sweet sorghum approached an asymptote with a maximum value that depended on the physical form of the sample. The model could help in understanding the mechanics of juice extraction from chopped sweet sorghum.展开更多
基金Project(2011ZX05013-006)supported by the National Science and Technology Project of China
文摘As for ultra-low permeability reservoir,the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops.Combined with non-linear porous flow characteristics,the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models' well pattern adaptability.Through experiments,the models' pressure distribution is measured and on which basis,the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region,non-linear porous flow region,and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve.The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability,while the worst is inverted nine-spot equilateral well pattern.With the increase of drawdown pressure,dead oil region decreases,pressure sweep efficiency and deliverability index increase; meantime,the deliverability index of rectangular well pattern has much more rational increase.Under the same drawdown pressure,the rectangular well pattern has the largest pressure sweep efficiency.
文摘Juice extraction from chopped sweet sorghum is an example of flow through porous media. Darcy’s law is often used to express this type of phenomenon. However, using Darcy’s law to construct a mathematical model to predict juice extraction from chopped sweet sorghum is difficult, because the volume of the porous media changes during the pressing operations. A mathematical model was developed from fundamental analysis to predict the juice extraction ratio of chopped sweet sorghum, and experiments were conducted to verify the model. An experimental piston-cylinder assembly was developed to conduct the validation experiments. The parameters in the developed model were estimated by using non-linear regression analysis from the experimental data. Plots of the mathematical model agreed well with experimental data. R^2（coefficient of determination） values for all the regressions studied were higher than 0.99. Results showed that the juice extraction ratio of chopped sweet sorghum approached an asymptote with a maximum value that depended on the physical form of the sample. The model could help in understanding the mechanics of juice extraction from chopped sweet sorghum.
