A mathematical model, fully coupling multiple porous media deformation and fluid flow, was established based on the elastic theory of porous media and fluid-solid coupling mechanism in tight oil reservoirs. The finite...A mathematical model, fully coupling multiple porous media deformation and fluid flow, was established based on the elastic theory of porous media and fluid-solid coupling mechanism in tight oil reservoirs. The finite element method was used to determine the numerical solution and the accuracy of the model was verified. On this basis, the model was used to simulate productivity of multistage fractured horizontal wells in tight oil reservoirs. The results show that during the production of tight oil wells, the reservoir region close to artificial fractures deteriorated in physical properties significantly, e.g. the aperture and conductivity of artificial fractures dropped by 52.12% and 89.02% respectively. The simulations of 3000-day production of a horizontal well in tight oil reservoir showed that the predicted productivity by the uncoupled model had an error of 38.30% from that by the fully-coupled model. Apparently, ignoring the influence of fluid-solid interaction effect led to serious deviations of the productivity prediction results. The productivity of horizontal well in tight oil reservoir was most sensitive to the start-up pressure gradient, and second most sensitive to the opening of artificial fractures. Enhancing the initial conductivity of artificial fractures was helpful to improve the productivity of tight oil wells. The influence of conductivity, spacing, number and length of artificial fractures should be considered comprehensively in fracturing design. Increasing the number of artificial fractures unilaterally could not achieve the expected increase in production.展开更多
Based on the displacement discontinuity method and the discrete fracture unified pipe network model,a sequential iterative numerical method was used to build a fracturing-production integrated numerical model of shale...Based on the displacement discontinuity method and the discrete fracture unified pipe network model,a sequential iterative numerical method was used to build a fracturing-production integrated numerical model of shale gas well considering the two-phase flow of gas and water.The model accounts for the influence of natural fractures and matrix properties on the fracturing process and directly applies post-fracturing formation pressure and water saturation distribution to subsequent well shut-in and production simulation,allowing for a more accurate fracturing-production integrated simulation.The results show that the reservoir physical properties have great impacts on fracture propagation,and the reasonable prediction of formation pressure and reservoir fluid distribution after the fracturing is critical to accurately predict the gas and fluid production of the shale gas wells.Compared with the conventional method,the proposed model can more accurately simulate the water and gas production by considering the impact of fracturing on both matrix pressure and water saturation.The established model is applied to the integrated fracturing-production simulation of practical horizontal shale gas wells.The simulation results are in good agreement with the practical production data,thus verifying the accuracy of the model.展开更多
The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growt...The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.展开更多
The toxic effect of different solubilizing excipients on the growth and metabolism of Tetrahymena thermophila BF5(T.t.BF5) at various concentrations was investigated by microcalorimetry.The thermogenic curves of T.t.B...The toxic effect of different solubilizing excipients on the growth and metabolism of Tetrahymena thermophila BF5(T.t.BF5) at various concentrations was investigated by microcalorimetry.The thermogenic curves of T.t.BF5 growth were determined at 28°C,and were evaluated by dynamic parameters.The results indicated that the values of growth rate constant(k),maximum power(P1,P2),peak time(T1,T2) and total quantity of heat(Q) varied for different excipients.There was a good linear relationship between k and concentrations(r>0.95,P<0.01).5% inhibition concentration(IC5) of poloxamer 188,Tween 80,PEG 600,PEG 400 and Tween 20 was 2.18,1.07,1.35,0.58,and 0.045 mg/mL,respectively.After the principal component analysis(PCA),Q,k and P1 could characterize the effect of these excipients on T.t.BF5 growth.Comprehensive evaluation indicated that compared with the control group,poloxamer 188 had the weakest toxicity and Tween 20 had the strongest toxicity.展开更多
基金Supported by the National Science and Technology Major Project (2017ZX05013-005)。
文摘A mathematical model, fully coupling multiple porous media deformation and fluid flow, was established based on the elastic theory of porous media and fluid-solid coupling mechanism in tight oil reservoirs. The finite element method was used to determine the numerical solution and the accuracy of the model was verified. On this basis, the model was used to simulate productivity of multistage fractured horizontal wells in tight oil reservoirs. The results show that during the production of tight oil wells, the reservoir region close to artificial fractures deteriorated in physical properties significantly, e.g. the aperture and conductivity of artificial fractures dropped by 52.12% and 89.02% respectively. The simulations of 3000-day production of a horizontal well in tight oil reservoir showed that the predicted productivity by the uncoupled model had an error of 38.30% from that by the fully-coupled model. Apparently, ignoring the influence of fluid-solid interaction effect led to serious deviations of the productivity prediction results. The productivity of horizontal well in tight oil reservoir was most sensitive to the start-up pressure gradient, and second most sensitive to the opening of artificial fractures. Enhancing the initial conductivity of artificial fractures was helpful to improve the productivity of tight oil wells. The influence of conductivity, spacing, number and length of artificial fractures should be considered comprehensively in fracturing design. Increasing the number of artificial fractures unilaterally could not achieve the expected increase in production.
基金Supported by the National Natural Science Foundation of China(52374043)Key Program of the National Natural Science Foundation of China(52234003).
文摘Based on the displacement discontinuity method and the discrete fracture unified pipe network model,a sequential iterative numerical method was used to build a fracturing-production integrated numerical model of shale gas well considering the two-phase flow of gas and water.The model accounts for the influence of natural fractures and matrix properties on the fracturing process and directly applies post-fracturing formation pressure and water saturation distribution to subsequent well shut-in and production simulation,allowing for a more accurate fracturing-production integrated simulation.The results show that the reservoir physical properties have great impacts on fracture propagation,and the reasonable prediction of formation pressure and reservoir fluid distribution after the fracturing is critical to accurately predict the gas and fluid production of the shale gas wells.Compared with the conventional method,the proposed model can more accurately simulate the water and gas production by considering the impact of fracturing on both matrix pressure and water saturation.The established model is applied to the integrated fracturing-production simulation of practical horizontal shale gas wells.The simulation results are in good agreement with the practical production data,thus verifying the accuracy of the model.
基金supported by the National Natural Science Foundation of China (30625042 and 30873385)the Key Technology of the National Great New Drugs Development Project of China (2009ZX09502-003 and 2009ZX09308-005)
文摘The action of Cornu Cervi Pantotrichum (CCP), Cornu Cervi (CC) and Cornu Saigae Tataricae (CST) on Escherichia coli growth were investigated using microcalorimetry to find the heat change regularity of microbial growth. The similarity of thermogenic curves and thermodynamics parameters were investigated as evaluation index, such as the growth rate constant in the first expo- nential phase (k1), maximum power in the first exponential phase (P1), maximum power in the secondary exponential phase (P2), peak time in the first exponential phase (T1), peak time in the stationary phase (T2) and the total heat production in stage 1 (Q1), and the total heat production in stage 2 (Q2). Chemometric analysis was used as a reference for the bioactivity evaluation of medicinal animal horns. The results indicated that the similarity between CST and the control was smaller than that between CCP, CC and the control. Both CCP and CC could increase the heat in the microbial growth, whereas CST decreased it. The biotic thermal activity of different medicinal animal horns was objectively, qualitatively, and quantitatively evaluated by the similarity of thermogenic curves and thermodynamics parameters analysis.
基金supported by the Special Foundation of Research on the Traditional Chinese Medicine Vocation (200708006)National Major Special Foundation for New Key Drug Innovation of China (2009ZX09502-003)Project of National Science & Technology Pillar Program of China in the 11th Five-Year Period (2008B AI55B04)
文摘The toxic effect of different solubilizing excipients on the growth and metabolism of Tetrahymena thermophila BF5(T.t.BF5) at various concentrations was investigated by microcalorimetry.The thermogenic curves of T.t.BF5 growth were determined at 28°C,and were evaluated by dynamic parameters.The results indicated that the values of growth rate constant(k),maximum power(P1,P2),peak time(T1,T2) and total quantity of heat(Q) varied for different excipients.There was a good linear relationship between k and concentrations(r>0.95,P<0.01).5% inhibition concentration(IC5) of poloxamer 188,Tween 80,PEG 600,PEG 400 and Tween 20 was 2.18,1.07,1.35,0.58,and 0.045 mg/mL,respectively.After the principal component analysis(PCA),Q,k and P1 could characterize the effect of these excipients on T.t.BF5 growth.Comprehensive evaluation indicated that compared with the control group,poloxamer 188 had the weakest toxicity and Tween 20 had the strongest toxicity.