The processes of flooding—water flooding, polymer flooding and ternary combination flooding—were simulated respectively on a 2-D positive rhythm profile geological model by using the ASP numerical modeling softw...The processes of flooding—water flooding, polymer flooding and ternary combination flooding—were simulated respectively on a 2-D positive rhythm profile geological model by using the ASP numerical modeling software developed by RIPED (Yuan, et al. 1995). The recovery coefficient, remaining oil saturation, sweep efficiency and displacement efficiency were calculated and correlated layer by layer. The results show that the sweep efficiency and displacement efficiency work different effects on different layers in the severely heterogeneous reservoir. The study shows that the displacement efficiency and sweep efficiency play different roles in different layers for severely heterogeneous reservoirs. The displacement efficiency contributes mainly to the high permeability zones, the sweep efficiency to the low permeability zones, both of which contribute to the middle permeable zones. To improve the sweep efficiency in the low permeability zones is of significance for enhancing the whole recovery of the reservoir. It is an important path for improving the effectiveness of chemical flooding in the severely heterogeneous reservoirs to inject ternary combination slug after profile control.展开更多
The kinetics of epoxidation of methylbutene with structurally identical methylbutane hydroperoxide was studied in the presence of a molybdenum catalyst. The analysis of the rate curves suggested the most probable sche...The kinetics of epoxidation of methylbutene with structurally identical methylbutane hydroperoxide was studied in the presence of a molybdenum catalyst. The analysis of the rate curves suggested the most probable scheme of the process. The revealed features of the process and its mathematical description make it possible to more competently design a reactor unit for the commercial production of isoprene according to the developed scheme. The main kinetic constants were calculated.展开更多
Potassium （K） release characteristics in soil play a significant role in supplying available K. Information on K-release characteristics in soils of central Iran is limited. The objectives of this study were to dete...Potassium （K） release characteristics in soil play a significant role in supplying available K. Information on K-release characteristics in soils of central Iran is limited. The objectives of this study were to determine K release characteristics and correlations of K release rate constants with K extracted by different chemical methods in surface soils of ten calcareous soils of central Iran. The kinetics of K release in the soils was determined by successive extraction with 0.01 mol L-1 CaC12 in a period of 2-2017 h at 25±1℃. Soil K was extracted by distilled water, 0.5 mol L-1 MgNO3, 0.002 mol L-1 SrC12, 0.1 mol L-1 BaC12, 0.01 mol L-1 CaC12, 1 mol L-1 NaC1, 1 mol L-1 boiling HNO3, 1 mol L-1 NH4OAC, Mehlich 1, 0.002 mol L-1 SrC12 ＋ 0.05 mol L-1 citric acid, and ammonium bicarbonate-diethylenetriamine pentaacetic acid （AB-DTPA）. A plot of cumulative amounts of K released showed a discontinuity in slope at 168 h. Thus, two equations were applied to two segments of the total reaction time （2-168 and 168-2 017 h）. Cumulative amounts of K released ranged from 55 to 299 mg kg-1 in 2-168 h and from 44 to 119 mg kg-1 in 168-2 017 h. Release kinetics of K in the two time segments conformed fairly well to parabolic diffusion, simplified Elovich, and power function models. There was a wide variation in the K release rate constants. Increasingly higher average concentrations of soil K were extracted by distilled water, Mehlich 1, SrC12, CaC12, SrC12 ＋ citric acid, AB-DTPA, MgNO3, NaCI, NH4OAc, BaCI2, and HNO3. Potassium release rate constants were significantly correlated with K extracted. The results of this study showed that information obtained from mathematical modeling in two reaction time segments can help to estimate the K-supplying power of soils.展开更多
基金This project is supported by the China National Key Basis Research Project (No: G1999022512)
文摘The processes of flooding—water flooding, polymer flooding and ternary combination flooding—were simulated respectively on a 2-D positive rhythm profile geological model by using the ASP numerical modeling software developed by RIPED (Yuan, et al. 1995). The recovery coefficient, remaining oil saturation, sweep efficiency and displacement efficiency were calculated and correlated layer by layer. The results show that the sweep efficiency and displacement efficiency work different effects on different layers in the severely heterogeneous reservoir. The study shows that the displacement efficiency and sweep efficiency play different roles in different layers for severely heterogeneous reservoirs. The displacement efficiency contributes mainly to the high permeability zones, the sweep efficiency to the low permeability zones, both of which contribute to the middle permeable zones. To improve the sweep efficiency in the low permeability zones is of significance for enhancing the whole recovery of the reservoir. It is an important path for improving the effectiveness of chemical flooding in the severely heterogeneous reservoirs to inject ternary combination slug after profile control.
文摘The kinetics of epoxidation of methylbutene with structurally identical methylbutane hydroperoxide was studied in the presence of a molybdenum catalyst. The analysis of the rate curves suggested the most probable scheme of the process. The revealed features of the process and its mathematical description make it possible to more competently design a reactor unit for the commercial production of isoprene according to the developed scheme. The main kinetic constants were calculated.
文摘Potassium （K） release characteristics in soil play a significant role in supplying available K. Information on K-release characteristics in soils of central Iran is limited. The objectives of this study were to determine K release characteristics and correlations of K release rate constants with K extracted by different chemical methods in surface soils of ten calcareous soils of central Iran. The kinetics of K release in the soils was determined by successive extraction with 0.01 mol L-1 CaC12 in a period of 2-2017 h at 25±1℃. Soil K was extracted by distilled water, 0.5 mol L-1 MgNO3, 0.002 mol L-1 SrC12, 0.1 mol L-1 BaC12, 0.01 mol L-1 CaC12, 1 mol L-1 NaC1, 1 mol L-1 boiling HNO3, 1 mol L-1 NH4OAC, Mehlich 1, 0.002 mol L-1 SrC12 ＋ 0.05 mol L-1 citric acid, and ammonium bicarbonate-diethylenetriamine pentaacetic acid （AB-DTPA）. A plot of cumulative amounts of K released showed a discontinuity in slope at 168 h. Thus, two equations were applied to two segments of the total reaction time （2-168 and 168-2 017 h）. Cumulative amounts of K released ranged from 55 to 299 mg kg-1 in 2-168 h and from 44 to 119 mg kg-1 in 168-2 017 h. Release kinetics of K in the two time segments conformed fairly well to parabolic diffusion, simplified Elovich, and power function models. There was a wide variation in the K release rate constants. Increasingly higher average concentrations of soil K were extracted by distilled water, Mehlich 1, SrC12, CaC12, SrC12 ＋ citric acid, AB-DTPA, MgNO3, NaCI, NH4OAc, BaCI2, and HNO3. Potassium release rate constants were significantly correlated with K extracted. The results of this study showed that information obtained from mathematical modeling in two reaction time segments can help to estimate the K-supplying power of soils.
