Modeling of Transient Pressure Response for CO2Flooding Process by Incorporating Convection and Diffusion Driven Mass Transfer

2017 ◽  
pp. 185-198
Author(s):  
Jianli Li ◽  
Gang Zhao
Keyword(s):  
Mass Transfer ◽  
Pressure Response ◽  
Transient Pressure ◽  
And Diffusion

scholarly journals New Understanding of Transient Pressure Response in the Transition Zone of Oil-Water and Gas-Water Systems

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Wenbin Xu ◽  
Zhihui Liu ◽  
Jie Liu ◽  
Yongfei Yang
Keyword(s):  
Transition Zone ◽  
Outer Boundary ◽  
Water System ◽  
Pressure Response ◽  
Transient Pressure ◽  
Type Curves ◽  
Boundary Type ◽  
Study Results ◽  
Effective Mobility ◽  
Oil Water

Well test analysis requires a preselected model, which relies on the context input and the diagnostic result through the pressure logarithmic derivative curve. Transient pressure outer boundary response heavily impacts on the selection of such a model. Traditional boundary-type curves used for such diagnostic purpose are only suitable for single-phase flow in a homogeneous reservoir, while practical situations are often much more complicated. This is particularly true when transient pressure is derived during the field development phase, for example, from permanent down-hole gauge (PDG), where outer boundary condition such as an active aquifer with a transition zone above it plays a big role in dominating the late time pressure response. In this case, capillary pressure and the total mobility in the transition zone have significant effect on the pressure response. This effect is distinctly different for oil-water system and gas water system, which will result in the pressure logarithmic derivatives remarkably different from the traditional boundary-type curves. This paper presents study results derived through theoretical and numerical well testing approaches to solve this problem. The outcome of this study can help in understanding the reservoir behavior and guiding the management of mature field. According to the theoretical development by Thompson, a new approach was derived according to Darcy’s law, which shows that pressure response in the transition zone is a function of total effective mobility. For oil-water system, the total effective mobility increases with an increase in the radius of transition zone, while for gas-water system, the effect is opposite.

scholarly journals Designing a Mesoporous Zeolite Catalyst for Products Optimizing in n-Decane Hydrocraking

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 766 ◽  
Author(s):  
Li Tan ◽  
Xiaoyu Guo ◽  
Xinhua Gao ◽  
Noritatsu Tsubaki
Keyword(s):  
Mass Transfer ◽  
Active Sites ◽  
Zeolite Catalyst ◽  
Catalytic Performance ◽  
Hydrogen Spillover ◽  
Mesoporous Zeolite ◽  
Mesoporous Catalyst ◽  
Hydrogen Atoms ◽  
Effect Factors ◽  
And Diffusion

Mesoporous ZSM-5 zeolite is developed to enhance the catalytic performance in a hydrocracking reaction. The generated mesopores and mesoporous channels in the new catalyst supply more opportunities for reactant accessing the active sites according to the better mass transfer and diffusion. Meanwhile, the acidity of the mesoporous catalyst is also weakened because of the removal of Si and Al species from its MFI structure, which makes the products distribution drift to more valued chemicals such as olefins. In the modified mesoporous ZSM-5 zeolites via different metallic promoters, the olefins’ selectivity increases as the alkalinity of the catalyst increases. The reason for this is that the formed olefins will be further hydrogenated into corresponding alkanes immediately over the extremely acidic zeolite catalyst. Hence, the moderate alkalinity will limit this process, while at the same time the remaining olefins products will too. Furthermore, the Pd-based mesoporous ZSM-5 zeolite shows an excellent n-decane conversion and high propane selectivity due to the occurrence of hydrogen spillover via the Pd promoter. The phenomenon of hydrogen spillover supplies more chemisorbed sites of hydrogen atoms for hydrocracking and hydrogenating in this reaction. In short, this study explores the important effect factors in n-decane hydrocracking reaction activity and products distribution. It also shows a potential for the further industrial application of petroleum-derived fuel hydrocracking according to the optimized products distribution under metallic promoted mesoporous zeolite.

scholarly journals Mathematical modeling on non-dispersive extraction of germanium from aqueous solutions using Aliquat 336

2018 ◽  
Vol 78 (12) ◽  
pp. 2489-2499
Author(s):  
Hossein Kamran Haghighi ◽  
Mehdi Irannajad ◽  
Agustin Fortuny ◽  
Ana Maria Sastre
Keyword(s):  
Mathematical Modeling ◽  
Mass Transfer ◽  
Correlation Coefficients ◽  
Aliquat 336 ◽  
Transfer Coefficients ◽  
Extraction Equilibrium ◽  
Flat Sheet ◽  
Flat Sheet Membrane ◽  
Error Bias ◽  
And Diffusion

Abstract In this work, the mathematical modeling of the facilitated transport of germanium (non-dispersive extraction) through a flat sheet membrane with an Aliquat 336 carrier was described. The flat sheet supported liquid membrane (FSSLM) experiments were performed under conditions germanium ≈ 100 mg/L, tartaric acid concentration of 2.76 mmol/L, and carrier concentrations of 2.5–10%v/v. The extraction equilibrium, mass transfer, and diffusion equations based on Fick's law were the principles of modeling. Modeling was carried out by programming in Matlab mathematical software to obtain the extraction (Kex) and mass transfer constants (Km) as the objective parameters. According to the model resolution, Kex and Km were found to be 0.178 and 9.25 × 10−2 cm/s, respectively. The correlation coefficients between model and experimental data relating to the Aliquat 336 concentrations of 2.5, 5, 7.5, and 10%v/v were found as 0.96, 0.98, 0.99, and 0.92. The parameters of root mean square error, bias, and scatter index showed the model accuracy. In addition, diffusion coefficients relating to Aliquat 336 concentrations of 2.5, 5, 7.5, and 10%v/v were calculated using mass transfer coefficients to be 2.4 × 10−4, 2.23 × 10−4, 1.91 × 10−4, and 1.79 × 10−4 cm2/s, respectively.

Understanding the Phenomenon of Dissolved Gas Migration of Gas in Riser During Drilling Operations

2019 ◽  
Author(s):  
Syed Y. Nahri ◽  
Yuanhang Chen ◽  
Wesley Williams ◽  
Otto Santos ◽  
Louis Thibodeaux ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Drilling Fluid ◽  
Gas Absorption ◽  
Base Case ◽  
Drilling Fluids ◽  
Dissolved Carbon ◽  
Experimental Apparatus ◽  
Drilling Operations ◽  
And Diffusion

Abstract The prevention and control of gas kicks is a major concern in the petroleum industry during deepwater drilling operations. The problem is further aggravated when dealing with synthetic and oil-based muds (SOBM and OBM) that can dissolve a gas influx entering the wellbore. Due to the solubility of formation gases in drilling fluids, the gas cut mud resulting from gas absorption has a density lower than that of overlaying unsaturated drilling fluid. Lab scale experimental tests were conducted in order to understand whether buoyancy-induced convection and diffusion attribute to mass transfer of a dissolved influx. Experiments were performed on a low-pressure mass transfer apparatus using carbon-dioxide (CO2) and mineral oil to study the extent of mass transfer due to buoyancy induced convective flow and diffusion. Measurements were made on the axial distance travelled by the dissolved carbon dioxide and gas concentration over the length of a pipe by measuring the mass of gas accumulated in different test sections of the experimental apparatus. This arises due to a concentration gradient developed when contaminated fluid comes in contact with a fresh column of drilling fluid. Experimentally obtained measurements made on the mass transfer coefficient are used to tune simulations carried out using a computational fluid dynamic (CFD) software — ANSYS Fluent. This enables us to replicate field scenarios to study the extent of well control issues that could arise when a gas influx enters the wellbore, even when circulation has ceased. Results obtained here can be used as a base case to understand a similar phenomenon occurring when extended to other fluid systems such as that of a natural gas influx in synthetic oil-based drilling fluids.

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