Constructing an accurate geological model of the reservoir is a preliminary to make any reliable prediction of a reservoir’s performance. Afterward, one needs to simulate the flow to predict the reservoir’s dynamic behaviour. This process usually is associated with high computational costs. Therefore, alternative methods such as the percolation approach for rapid estimation of reservoir efficiency are quite desirable. This study tries to address the Well Testing (WT) interpretation of heterogeneous reservoirs, constructed from two extreme permeabilities, 0 and K. In particular, we simulated a drawdown test on typical site percolation mediums, occupied to fraction “p” at a constant rate Q/h, to compute the well-known pressure derivative (dP/dlnt). This derivative provides us with “apparent” permeability values, a significant property to move forward with flow prediction. It is good to mention that the hypothetical wellbore locates in the middle of the reservoir with assumed conditions. Commercial software utilized to perform flow simulations and well test analysis. Next, the pressure recorded against time at different realizations and values of p. With that information provided, the permeability of the medium is obtained. Finally, the permeability change of this reservoir is compared to the permeability alteration of a homogeneous one and following that, its dependency on the model parameters has been analysed. The result shows a power-law relation between average permeability (considering all realizations) and the occupancy probability “p”. This conclusion helps to improve the analysis of well testing for heterogeneous reservoirs with percolation structures.
{"title":"Analysis of well testing results for single phase flow in reservoirs with percolation structure","authors":"Elahe Shahrian, M. Masihi","doi":"10.2516/OGST/2020092","DOIUrl":"https://doi.org/10.2516/OGST/2020092","url":null,"abstract":"Constructing an accurate geological model of the reservoir is a preliminary to make any reliable prediction of a reservoir’s performance. Afterward, one needs to simulate the flow to predict the reservoir’s dynamic behaviour. This process usually is associated with high computational costs. Therefore, alternative methods such as the percolation approach for rapid estimation of reservoir efficiency are quite desirable. This study tries to address the Well Testing (WT) interpretation of heterogeneous reservoirs, constructed from two extreme permeabilities, 0 and K. In particular, we simulated a drawdown test on typical site percolation mediums, occupied to fraction “p” at a constant rate Q/h, to compute the well-known pressure derivative (dP/dlnt). This derivative provides us with “apparent” permeability values, a significant property to move forward with flow prediction. It is good to mention that the hypothetical wellbore locates in the middle of the reservoir with assumed conditions. Commercial software utilized to perform flow simulations and well test analysis. Next, the pressure recorded against time at different realizations and values of p. With that information provided, the permeability of the medium is obtained. Finally, the permeability change of this reservoir is compared to the permeability alteration of a homogeneous one and following that, its dependency on the model parameters has been analysed. The result shows a power-law relation between average permeability (considering all realizations) and the occupancy probability “p”. This conclusion helps to improve the analysis of well testing for heterogeneous reservoirs with percolation structures.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80386762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthetic plugs are available to understand oilfield properties and the behavior of oil in reservoirs where natural plugs cannot be extracted. Specifically, in cases where it is necessary to reproduce representative mineralogical and petrophysical characteristics from carbonate reservoirs, it is evident that there is a lack of publications focusing on synthetic plug construction. In this work, a methodology to construct synthetic carbonate plugs is proposed using disintegrated carbonate rock with controlled particle size, mixed in different weight fraction, uniaxial compaction with controlled load force velocity, pH, temperature, and bonding materials. Preliminary analysis of consolidation (basic consolidation and consolidation by water immersion test), wettability (contact angle measurements) and petrophysical properties (nitrogen expansion porosimetry measurements and theoretical porosity calculation) are reported in this study to determine which composition of the synthetic samples provides similar properties compared to that expected for natural rocks from carbonate reservoirs. Two compositions are recommended to construct synthetic samples: Composition 1 with a total quantity of 100 g of base material (50% w/w of <20 μm, 50% w/w of 20–74 μm) + 5% w/w of amide wax (relative to 100 g of base material) + 6% w/w (relative to 100 g of base material) of pH 3 hydrochloric acid solution; and Composition 2 with a total quantity of 100 g of base material (50% w/w of 150–300 μm, 50% w/w of 300–600 μm) + 5% w/w (relative to 100 g of base material) of amide wax + 6% w/w (relative to 100 g of base material) of pH 3 hydrochloric acid solution. In addition to the compositions, it is necessary to follow the reported procedure based on the uniaxial compaction with controlled load force (200 kN) and velocity (25 mm/min) and the sample’s drying temperature of 100 °C for 1 h aiming to obtain similar samples. These preliminary results will guide further dedicated petrophysical and wettability analysis to deeply understanding these sample’s properties and enhance the construction of synthetic samples more similar to the natural rocks from carbonate reservoirs.
{"title":"Preliminary analyses of synthetic carbonate plugs: consolidation, petrophysical and wettability properties","authors":"Jhonatan Jair Arismendi Florez, J. V. Ferrari","doi":"10.2516/OGST/2020087","DOIUrl":"https://doi.org/10.2516/OGST/2020087","url":null,"abstract":"Synthetic plugs are available to understand oilfield properties and the behavior of oil in reservoirs where natural plugs cannot be extracted. Specifically, in cases where it is necessary to reproduce representative mineralogical and petrophysical characteristics from carbonate reservoirs, it is evident that there is a lack of publications focusing on synthetic plug construction. In this work, a methodology to construct synthetic carbonate plugs is proposed using disintegrated carbonate rock with controlled particle size, mixed in different weight fraction, uniaxial compaction with controlled load force velocity, pH, temperature, and bonding materials. Preliminary analysis of consolidation (basic consolidation and consolidation by water immersion test), wettability (contact angle measurements) and petrophysical properties (nitrogen expansion porosimetry measurements and theoretical porosity calculation) are reported in this study to determine which composition of the synthetic samples provides similar properties compared to that expected for natural rocks from carbonate reservoirs. Two compositions are recommended to construct synthetic samples: Composition 1 with a total quantity of 100 g of base material (50% w/w of <20 μm, 50% w/w of 20–74 μm) + 5% w/w of amide wax (relative to 100 g of base material) + 6% w/w (relative to 100 g of base material) of pH 3 hydrochloric acid solution; and Composition 2 with a total quantity of 100 g of base material (50% w/w of 150–300 μm, 50% w/w of 300–600 μm) + 5% w/w (relative to 100 g of base material) of amide wax + 6% w/w (relative to 100 g of base material) of pH 3 hydrochloric acid solution. In addition to the compositions, it is necessary to follow the reported procedure based on the uniaxial compaction with controlled load force (200 kN) and velocity (25 mm/min) and the sample’s drying temperature of 100 °C for 1 h aiming to obtain similar samples. These preliminary results will guide further dedicated petrophysical and wettability analysis to deeply understanding these sample’s properties and enhance the construction of synthetic samples more similar to the natural rocks from carbonate reservoirs.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73323557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mina Shafiabadi, A. Kamkar-Rouhani, Seyed Reza Ghavami Riabi, A. R. Kahoo, B. Tokhmechi
Because of the significant impact of fractures on production in hydrocarbon reservoirs, identification of these phenomena is a very important issue. Image logs are one of the best tools for revealing and studying fractures in reservoir and researcher can get lots of information about geological features in wells, by studying and analyzing these logs. In this research, two approaches have been used to determine the fractures in two wells A and B located in one of the oil fields in southwest of Iran. In the first approach, using Geolog software (version-7), after processing and correction of raw image log data, the number, position, dip, extension, layering, density and expansion of fractures have been identified. In the second approach, considering that the fractures in FMI images have edges, the Canny and Sobel filters as edge detection operators in image processing have been used to detect fractures in these images.
{"title":"Identification of reservoir fractures on FMI image logs using Canny and Sobel edge detection algorithms","authors":"Mina Shafiabadi, A. Kamkar-Rouhani, Seyed Reza Ghavami Riabi, A. R. Kahoo, B. Tokhmechi","doi":"10.2516/OGST/2020086","DOIUrl":"https://doi.org/10.2516/OGST/2020086","url":null,"abstract":"Because of the significant impact of fractures on production in hydrocarbon reservoirs, identification of these phenomena is a very important issue. Image logs are one of the best tools for revealing and studying fractures in reservoir and researcher can get lots of information about geological features in wells, by studying and analyzing these logs. In this research, two approaches have been used to determine the fractures in two wells A and B located in one of the oil fields in southwest of Iran. In the first approach, using Geolog software (version-7), after processing and correction of raw image log data, the number, position, dip, extension, layering, density and expansion of fractures have been identified. In the second approach, considering that the fractures in FMI images have edges, the Canny and Sobel filters as edge detection operators in image processing have been used to detect fractures in these images.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90676609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shaolin Hu, Shihua Wang, Naiquan Su, Xiwu Li, Qinghua Zhang
The whole process of the petrochemical industry involves flammable and explosive dangerous goods. The timely discovery of abnormalities or failures in the petrochemical process is crucial to ensure production safety. This paper sets up the approach to build the Digital Twin System (DTs) of a petrochemical process. Specifically, we decompose the petrochemical process into five levels one by one and build a digital twin plug-in for each component of the component layers, and then inversely decouple the process to assemble the DTs layer by layer. As a specific experimental example, the characteristic DTs is proposed to build modules of temperature field and pressure field and flow field, these DT modules are driven by practical industrial sampling data from cracking furnace, and three characteristic DTS modules stated above are integrated to form DTS. Based on the digital twin technology and DTs, we propose the logical structure of chemical process status monitoring and fault diagnosis in detail, which improves the safety and controllability of the petrochemical process.
{"title":"Digital twin based reference architecture for petrochemical monitoring and fault diagnosis","authors":"Shaolin Hu, Shihua Wang, Naiquan Su, Xiwu Li, Qinghua Zhang","doi":"10.2516/OGST/2020095","DOIUrl":"https://doi.org/10.2516/OGST/2020095","url":null,"abstract":"The whole process of the petrochemical industry involves flammable and explosive dangerous goods. The timely discovery of abnormalities or failures in the petrochemical process is crucial to ensure production safety. This paper sets up the approach to build the Digital Twin System (DTs) of a petrochemical process. Specifically, we decompose the petrochemical process into five levels one by one and build a digital twin plug-in for each component of the component layers, and then inversely decouple the process to assemble the DTs layer by layer. As a specific experimental example, the characteristic DTs is proposed to build modules of temperature field and pressure field and flow field, these DT modules are driven by practical industrial sampling data from cracking furnace, and three characteristic DTS modules stated above are integrated to form DTS. Based on the digital twin technology and DTs, we propose the logical structure of chemical process status monitoring and fault diagnosis in detail, which improves the safety and controllability of the petrochemical process.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76184310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dilayne Santos Oliveira, B. Horowitz, J. R. Rojas Tueros
Proxy models are widely used to estimate parameters such as interwell connectivity in the development and management of petroleum fields due to their low computational cost and not require prior knowledge of reservoir properties. In this work, we propose a proxy model to determine both oil and water production to maximize reservoir profitability. The approach uses production history and the Capacitance and Resistance Model based on Producer wells (CRMP), together with the combination of two fractional flow models, Koval [Cao (2014) Development of a Two-phase Flow Coupled Capacitance Resistance Model. PhD Dissertation, The University of Texas at Austin, USA] and Gentil [(2005) The use of Multilinear Regression Models in patterned waterfloods: physical meaning of the regression coefficient. Master’s Thesis, The University of Texas at Austin, USA]. The proposed combined fractional flow model is called Kogen. The combined fractional flow model can be formulated as a constrained nonlinear function fitting. The objective function to be minimized is a measure of the difference between calculated and observed Water cut (Wcut) values or Net Present Values (NPV). The constraint limits the difference in water cuts of the Koval and Gentil models at the time of transition between the two. The problem can be solved using the Sequential Quadratic Programming (SQP) algorithm. The parameters of the CRMP model are the connectivity between wells, time constant and productivity index. These parameters can be found using a Nonlinear Least Squares (NLS) algorithm. With these parameters, it is possible to predict the liquid rate of the wells. The Koval and Gentil models are used to calculate the Wcut in each producer well over the concession period which in turn allows to determine the accumulated oil and water productions. To verify the quality of Kogen model to forecast oil and water productions, we formulated an optimization problem to maximize the reservoir profitability where the objective function is the NPV. The design variables are the injector and producer well controls (liquid rate or bottom hole pressure). In this work the optimization problem is solved using a gradient-based method, SQP. Gradients are approximated using an ensemble-based method. To validate the proposed workflow, we used two realistic reservoirs models, Brush Canyon Outcrop and Brugge field. The results are shown into three stages. In the first stage, we analyze the ensemble size for the gradient computation. Second, we compare the solutions obtained with the three fractional flow models (Koval, Gentil and Kogen) with results achieved directly from the simulator. Third, we use the solutions calculated with the proxy models as starting points for a new high-fidelity optimization process, using exclusively the simulator to calculate the functions involved. This study shows that the proposed combined model, Kogen, consistently generated more accurate results. Also, CRMP/Kogen proxy model has d
由于代理模型计算成本低，且不需要事先了解油藏性质，因此被广泛用于油田开发和管理中估计井间连通性等参数。在这项工作中，我们提出了一个代理模型来确定油和水的产量，以最大限度地提高油藏的盈利能力。该方法使用生产历史和基于生产井的电容和电阻模型(CRMP)，以及两种分流模型的结合，Koval [Cao(2014)开发了两相流耦合电容电阻模型。dr . Dissertation, University of Texas at Austin, USA] and Gentil [(2005) Multilinear Regression Models在模式水驱中的应用:回归系数的物理意义。硕士论文，德克萨斯大学奥斯汀分校，美国]。提出的组合分流模型被称为Kogen。组合式分流模型可表述为约束非线性函数拟合。要最小化的目标函数是测量计算和观测到的含水率(Wcut)值或净现值(NPV)之间的差异。这一约束限制了Koval模型和Gentil模型在两者过渡时含水率的差异。该问题可以用序列二次规划(SQP)算法求解。CRMP模型的参数为井间连通性、时间常数和产能指数。这些参数可以使用非线性最小二乘(NLS)算法找到。有了这些参数，就可以预测井的产液率。Koval和Gentil模型用于计算特许期内每口生产井的Wcut，从而可以确定累积的油水产量。为了验证Kogen模型预测油水产量的质量，提出了以NPV为目标函数的油藏盈利能力最大化优化问题。设计变量是注入井和生产井控制(液量或井底压力)。在本工作中，采用基于梯度的方法SQP来解决优化问题。梯度近似使用基于集成的方法。为了验证提出的工作流程，我们使用了两个真实的油藏模型，即Brush Canyon露头和Brugge油田。研究结果分为三个阶段。在第一阶段，我们分析了梯度计算的集合大小。其次，我们将三种分数阶流动模型(Koval, Gentil和Kogen)的解与直接从模拟器获得的结果进行了比较。第三，我们使用代理模型计算的解决方案作为新的高保真优化过程的起点，专门使用模拟器计算所涉及的函数。本研究表明，所提出的组合模型Kogen始终产生更准确的结果。此外，CRMP/Kogen代理模型也证明了它的适用性，特别是在模型构建可用数据有限的情况下，总能以较低的计算成本获得令人满意的生产预测结果。此外，它为高保真优化过程产生了良好的热启动，将模拟次数减少了约65%。
{"title":"Ensemble-based method with combined fractional flow model for waterflooding optimization","authors":"Dilayne Santos Oliveira, B. Horowitz, J. R. Rojas Tueros","doi":"10.2516/OGST/2020090","DOIUrl":"https://doi.org/10.2516/OGST/2020090","url":null,"abstract":"Proxy models are widely used to estimate parameters such as interwell connectivity in the development and management of petroleum fields due to their low computational cost and not require prior knowledge of reservoir properties. In this work, we propose a proxy model to determine both oil and water production to maximize reservoir profitability. The approach uses production history and the Capacitance and Resistance Model based on Producer wells (CRMP), together with the combination of two fractional flow models, Koval [Cao (2014) Development of a Two-phase Flow Coupled Capacitance Resistance Model. PhD Dissertation, The University of Texas at Austin, USA] and Gentil [(2005) The use of Multilinear Regression Models in patterned waterfloods: physical meaning of the regression coefficient. Master’s Thesis, The University of Texas at Austin, USA]. The proposed combined fractional flow model is called Kogen. The combined fractional flow model can be formulated as a constrained nonlinear function fitting. The objective function to be minimized is a measure of the difference between calculated and observed Water cut (Wcut) values or Net Present Values (NPV). The constraint limits the difference in water cuts of the Koval and Gentil models at the time of transition between the two. The problem can be solved using the Sequential Quadratic Programming (SQP) algorithm. The parameters of the CRMP model are the connectivity between wells, time constant and productivity index. These parameters can be found using a Nonlinear Least Squares (NLS) algorithm. With these parameters, it is possible to predict the liquid rate of the wells. The Koval and Gentil models are used to calculate the Wcut in each producer well over the concession period which in turn allows to determine the accumulated oil and water productions. To verify the quality of Kogen model to forecast oil and water productions, we formulated an optimization problem to maximize the reservoir profitability where the objective function is the NPV. The design variables are the injector and producer well controls (liquid rate or bottom hole pressure). In this work the optimization problem is solved using a gradient-based method, SQP. Gradients are approximated using an ensemble-based method. To validate the proposed workflow, we used two realistic reservoirs models, Brush Canyon Outcrop and Brugge field. The results are shown into three stages. In the first stage, we analyze the ensemble size for the gradient computation. Second, we compare the solutions obtained with the three fractional flow models (Koval, Gentil and Kogen) with results achieved directly from the simulator. Third, we use the solutions calculated with the proxy models as starting points for a new high-fidelity optimization process, using exclusively the simulator to calculate the functions involved. This study shows that the proposed combined model, Kogen, consistently generated more accurate results. Also, CRMP/Kogen proxy model has d","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72826381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liquid unloading is a very common and important issue in horizontal gas wells, and the presence of curve sections increases the complexity of the phenomenon and its study. Liquid loading in a gas well will sharply reduce production, therefore, the liquid-unloading onset of different curved pipes is essential to gas production. In this work, liquid-unloading onset experiments were conducted in curved pipes with different curvatures. Then, the critical gas velocity VsgCR can be determined according to the measured pressure gradients, liquid holdup, and liquid film reversal. This work analyzes the factors which will lead to the liquid unloading and explores the trend of the pipe curvature’s influence on the liquid unloading under laboratory conditions. The experimental results show that the critical gas velocity rises with the increase of pipe curvature, the increase is mainly due to the centrifugal force. The present work also compares the predicted results of the OLGA model and Beggs–Brill model with experimental data. The comparison results indicate that both models fit relatively well to the experimental data at the low superficial gas velocity, and both models have poor performance at high superficial gas velocity. The OLGA model fits the experimental data better than the Beggs–Brill model at high superficial gas velocity. The error analysis shows that most of the predicted data is not in good agreement with experimental data. Some errors between experimental data and calculation results are out of the range of 50%.
{"title":"An experimental study of liquid unloading in the curve section of horizontal gas wells","authors":"Shuzhe Shi","doi":"10.17632/X85BYRFWNV.1","DOIUrl":"https://doi.org/10.17632/X85BYRFWNV.1","url":null,"abstract":"Liquid unloading is a very common and important issue in horizontal gas wells, and the presence of curve sections increases the complexity of the phenomenon and its study. Liquid loading in a gas well will sharply reduce production, therefore, the liquid-unloading onset of different curved pipes is essential to gas production. In this work, liquid-unloading onset experiments were conducted in curved pipes with different curvatures. Then, the critical gas velocity VsgCR can be determined according to the measured pressure gradients, liquid holdup, and liquid film reversal. This work analyzes the factors which will lead to the liquid unloading and explores the trend of the pipe curvature’s influence on the liquid unloading under laboratory conditions. The experimental results show that the critical gas velocity rises with the increase of pipe curvature, the increase is mainly due to the centrifugal force. The present work also compares the predicted results of the OLGA model and Beggs–Brill model with experimental data. The comparison results indicate that both models fit relatively well to the experimental data at the low superficial gas velocity, and both models have poor performance at high superficial gas velocity. The OLGA model fits the experimental data better than the Beggs–Brill model at high superficial gas velocity. The error analysis shows that most of the predicted data is not in good agreement with experimental data. Some errors between experimental data and calculation results are out of the range of 50%.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80531385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Vignesh, Arockiyasamy Remigious Pradeep Kumar, N. Ganesh, V. Jayaseelan, Kumarasamy Sudhakar
First, second, third, and fourth-generation biofuels are continuously evolving as a promising substitute to petrodiesel catalyzed by energy depletion, economic and environmental considerations. Bio-diesel can be synthesized from various biomass sources, which are commonly divided into FAME and renewable biodiesel. FAME biodiesel is generally produced by the transesterification of vegetable oils and fats while renewable diesel is produced by hydro-deoxygenation of vegetable and waste oils and fats. The different generation, processing technologies and standards for FAME and renewable biodiesel are reviewed. Finally, the life cycle analysis and production cost of conventional and renewable biodiesel are described.
{"title":"Biodiesel and green diesel generation: an overview","authors":"P. Vignesh, Arockiyasamy Remigious Pradeep Kumar, N. Ganesh, V. Jayaseelan, Kumarasamy Sudhakar","doi":"10.2516/OGST/2020088","DOIUrl":"https://doi.org/10.2516/OGST/2020088","url":null,"abstract":"First, second, third, and fourth-generation biofuels are continuously evolving as a promising substitute to petrodiesel catalyzed by energy depletion, economic and environmental considerations. Bio-diesel can be synthesized from various biomass sources, which are commonly divided into FAME and renewable biodiesel. FAME biodiesel is generally produced by the transesterification of vegetable oils and fats while renewable diesel is produced by hydro-deoxygenation of vegetable and waste oils and fats. The different generation, processing technologies and standards for FAME and renewable biodiesel are reviewed. Finally, the life cycle analysis and production cost of conventional and renewable biodiesel are described.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84119736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hossein Gholamian, M. Ehsani, M. Nikookar, A. Mohammadi
Gas injection into a naturally fractured oil reservoir keeps the reservoir pressure and increments the initial recovery from the reservoir. The main aim of this work was to develop a numerical model to calculate the mass transfer (molecular diffusion and convection) between a gas injected in the fracture and residual fluid (gas and oil) in a matrix block. The dual continuum model is applied to describe flow behaviour and fluid recovery in porous media. Finally, the model is validated by comparing the outcomes with the results of two experimental works available in the literature. The mathematical model results are in agreement with the laboratory data including recovery of each component, saturation profile, and the pressure gradient between matrix and fracture. Modeling results show that after 25 days of N2 injection, the lighter and heavier components (C1 and C5) are recovered about 51% and 39%, respectively. These amounts for CO2 injection are 49% and 27%. It is found that the convection mechanism has a great effect on preventing the pressure drop of the reservoir during injection operations. In the nitrogen injection, without considering the convection, after 30 days, the matrix pressure reaches 1320 Psi from 1479 Psi but after 30 days, considering the convection, the pressure reaches 1473 Psi from 1479 Psi.
{"title":"Numerical modeling of molecular diffusion and convection effects during gas injection into naturally fractured oil reservoirs","authors":"Hossein Gholamian, M. Ehsani, M. Nikookar, A. Mohammadi","doi":"10.2516/ogst/2021065","DOIUrl":"https://doi.org/10.2516/ogst/2021065","url":null,"abstract":"Gas injection into a naturally fractured oil reservoir keeps the reservoir pressure and increments the initial recovery from the reservoir. The main aim of this work was to develop a numerical model to calculate the mass transfer (molecular diffusion and convection) between a gas injected in the fracture and residual fluid (gas and oil) in a matrix block. The dual continuum model is applied to describe flow behaviour and fluid recovery in porous media. Finally, the model is validated by comparing the outcomes with the results of two experimental works available in the literature. The mathematical model results are in agreement with the laboratory data including recovery of each component, saturation profile, and the pressure gradient between matrix and fracture. Modeling results show that after 25 days of N2 injection, the lighter and heavier components (C1 and C5) are recovered about 51% and 39%, respectively. These amounts for CO2 injection are 49% and 27%. It is found that the convection mechanism has a great effect on preventing the pressure drop of the reservoir during injection operations. In the nitrogen injection, without considering the convection, after 30 days, the matrix pressure reaches 1320 Psi from 1479 Psi but after 30 days, considering the convection, the pressure reaches 1473 Psi from 1479 Psi.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76817676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding subsurface flow, especially in fractured rocks only housing water through a few preferential pathways, is still challenging. The point is mainly associated with the poor accessibility of the subsurface and the lack of accurate representations for both heterogeneity and spatial distribution of water bearing bodies. This notwithstanding, highly-resolved geophysical investigations bring new images of the subsurface. This is exemplified over a fractured limestone aquifer at the site scale (for example, that of the radius of influence of an extraction well). On an experimental site, situated in the Cher region (France), two boreholes have been drilled for field experiments. Full Waveform Acoustic Logging (FWAL) and seismic experiments were conducted. Hybrid seismic imaging, which consists in combining refraction and reflection seismic results, has been carried out. Based on a four-step procedure, the processing of refracted and reflected waves provided two sections. After assemblage, these sections produced in a first step an extended time reflectivity section starting from the surface and, in a second step, a section over depth after calibration with Vertical Seismic Profile (VSP) and acoustic data. However, even the Very High Resolution (VHR) seismic methods do not have a sufficient vertical resolution to describe accurately the geological formation. The acoustic sections were processed to separate the different wave fields, to extract the criss-cross events and to build a criss-cross index log. A log of fracturation index, based on both criss-cross index and P-wave velocity measurements, was computed to detect the presence of fractures. After calibration, and under the assumption that the slower the P-wave velocity, the higher the permeability – porosity, a 3D seismic block of reflection can inform on preferential areas where flow should occur. At the scale of an open wellbore, acoustic loggings that measure wave velocities over a short distance within the well also inform on open features crosscut by the well. Finally, flow log measurements confirm the occurrence of flowing horizons that were previously marked by both seismic and acoustic data. Seismic and acoustic data are therefore suited to image contrasted hydraulic properties over fractured subsurface systems usually poorly documented.
{"title":"Characterizing flow in the first hundred-meter depth of a fractured aquifer using hybrid seismic methods, acoustic logging, and flow-log measurements","authors":"J. Mari, F. Delay, G. Porel, P. Gaudiani","doi":"10.2516/ogst/2021048","DOIUrl":"https://doi.org/10.2516/ogst/2021048","url":null,"abstract":"Understanding subsurface flow, especially in fractured rocks only housing water through a few preferential pathways, is still challenging. The point is mainly associated with the poor accessibility of the subsurface and the lack of accurate representations for both heterogeneity and spatial distribution of water bearing bodies. This notwithstanding, highly-resolved geophysical investigations bring new images of the subsurface. This is exemplified over a fractured limestone aquifer at the site scale (for example, that of the radius of influence of an extraction well). On an experimental site, situated in the Cher region (France), two boreholes have been drilled for field experiments. Full Waveform Acoustic Logging (FWAL) and seismic experiments were conducted. Hybrid seismic imaging, which consists in combining refraction and reflection seismic results, has been carried out. Based on a four-step procedure, the processing of refracted and reflected waves provided two sections. After assemblage, these sections produced in a first step an extended time reflectivity section starting from the surface and, in a second step, a section over depth after calibration with Vertical Seismic Profile (VSP) and acoustic data. However, even the Very High Resolution (VHR) seismic methods do not have a sufficient vertical resolution to describe accurately the geological formation. The acoustic sections were processed to separate the different wave fields, to extract the criss-cross events and to build a criss-cross index log. A log of fracturation index, based on both criss-cross index and P-wave velocity measurements, was computed to detect the presence of fractures. After calibration, and under the assumption that the slower the P-wave velocity, the higher the permeability – porosity, a 3D seismic block of reflection can inform on preferential areas where flow should occur. At the scale of an open wellbore, acoustic loggings that measure wave velocities over a short distance within the well also inform on open features crosscut by the well. Finally, flow log measurements confirm the occurrence of flowing horizons that were previously marked by both seismic and acoustic data. Seismic and acoustic data are therefore suited to image contrasted hydraulic properties over fractured subsurface systems usually poorly documented.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85394047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Energy is vital to the profitable growth of every nation and to stimulate new research. Only natural resources can meet the growing energy demand in recent years, biodiesel has become very interested in the energy as well as environmental advantages that it can be combined with mineral diesel fuel in any quantity. The research focuses on the study of the replacement of diesel with a safflower methyl ester. The engine tests shall be performed using the safflower methyl ester as fuel in the DI diesel engine. The combustion, emission and performance characteristics were studied using alternative fuels and mixtures. SAfflower Methyl Ester 80% (SAME80) and SAME100 have high heat release rates. Nitrogen oxides were higher by about 50%, carbon monoxide decreased by 10%, unburnt hydrocarbon was slightly higher and the thermal efficiency was higher for the SAME than for diesel fuel.
{"title":"Characterization and effect of the use of safflower methyl ester and diesel blends in the compression ignition engine","authors":"Balaji Venkatesan, Kaliappan Seeniappan, Ezhumalai Shanmugam, Socrates Subramanian, Jayaseelan Veerasundaram","doi":"10.2516/OGST/2021011","DOIUrl":"https://doi.org/10.2516/OGST/2021011","url":null,"abstract":"Energy is vital to the profitable growth of every nation and to stimulate new research. Only natural resources can meet the growing energy demand in recent years, biodiesel has become very interested in the energy as well as environmental advantages that it can be combined with mineral diesel fuel in any quantity. The research focuses on the study of the replacement of diesel with a safflower methyl ester. The engine tests shall be performed using the safflower methyl ester as fuel in the DI diesel engine. The combustion, emission and performance characteristics were studied using alternative fuels and mixtures. SAfflower Methyl Ester 80% (SAME80) and SAME100 have high heat release rates. Nitrogen oxides were higher by about 50%, carbon monoxide decreased by 10%, unburnt hydrocarbon was slightly higher and the thermal efficiency was higher for the SAME than for diesel fuel.","PeriodicalId":19424,"journal":{"name":"Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78526197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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