J. Čedík, M. Pexa, B. Peterka, M. Müller, M. Holubek, S. Hloch, M. Kučera
Liquid biofuels for compression ignition engines are often based on vegetable oils. In order to be used in compression ignition engine the vegetable oils have to be processed because of their high viscosity or it is also possible to use vegetable oils in fuel blends. In order to decrease the viscosity of the fuel blends containing crude vegetable oil the alcohol-based fuel admixtures can be used. The paper describes the effect of rapeseed oil–diesel fuel–n-butanol blends on combustion characteristics and solid particles production of turbocharged compression ignition engine. The 10% and 20% concentrations of n-butanol in the fuel blend were measured and analysed. The engine Zetor 1204, located in tractor Zetor Forterra 8641 with the power of 60kW and direct injection was used for the measurement. The engine was loaded through power take off shaft of the tractor using mobile dynamometer MAHA ZW500. The measurement was carried out in stabilized conditions at 20%, 60% and 100% engine load. The engine speed was kept at 1950 rpm. Tested fuel blends showed lower production of solid particles than diesel fuel and lower peak cylinder pressure and with increasing concentration of n-butanol in the fuel blend the ignition delay was prolonged and premixed phase of combustion was increased.
{"title":"Combustion characteristics of compression ignition engine fuelled with rapeseed oil–diesel fuel–n-butanol blends","authors":"J. Čedík, M. Pexa, B. Peterka, M. Müller, M. Holubek, S. Hloch, M. Kučera","doi":"10.2516/OGST/2021001","DOIUrl":"https://doi.org/10.2516/OGST/2021001","url":null,"abstract":"Liquid biofuels for compression ignition engines are often based on vegetable oils. In order to be used in compression ignition engine the vegetable oils have to be processed because of their high viscosity or it is also possible to use vegetable oils in fuel blends. In order to decrease the viscosity of the fuel blends containing crude vegetable oil the alcohol-based fuel admixtures can be used. The paper describes the effect of rapeseed oil–diesel fuel–n-butanol blends on combustion characteristics and solid particles production of turbocharged compression ignition engine. The 10% and 20% concentrations of n-butanol in the fuel blend were measured and analysed. The engine Zetor 1204, located in tractor Zetor Forterra 8641 with the power of 60kW and direct injection was used for the measurement. The engine was loaded through power take off shaft of the tractor using mobile dynamometer MAHA ZW500. The measurement was carried out in stabilized conditions at 20%, 60% and 100% engine load. The engine speed was kept at 1950 rpm. Tested fuel blends showed lower production of solid particles than diesel fuel and lower peak cylinder pressure and with increasing concentration of n-butanol in the fuel blend the ignition delay was prolonged and premixed phase of combustion was increased.","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":"79031237","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}
Xia Zhizeng, Jian Hou, Xuewu Wang, Xiaodong Dai, Ming-Tchang. Liu
The cyclic methane hydrate production method was proposed with CO2 and N2 mixture stimulation. The cyclic production model was established based on actual hydrate reservoir parameters, accordingly, the production characteristics were analyzed, and a sensitivity analysis was conducted. The results show the following: (1) The depressurization mechanism is dominant in the cyclic production. CH4 production and CH4 hydrate dissociation can be greatly enhanced because the cyclic process can effectively reduce the partial pressure of CH4 (gas phase). However, there is a limited effect for CO2 storage. (2) Heat supply is essential for continuous hydrate dissociation. The CH4 hydrate dissociation degree is the highest in the near-wellbore area; in addition, the fluid porosity and effective permeability are significantly improved, and the reservoir temperature is obviously decreased. (3) The initial CH4 hydrate saturation, absolute permeability, intrinsic CO2 hydrate formation kinetic constant, injection time and production time can significantly influence the production performance of the natural gas hydrate reservoir.
{"title":"Cyclic methane hydrate production stimulated with CO2 and N2","authors":"Xia Zhizeng, Jian Hou, Xuewu Wang, Xiaodong Dai, Ming-Tchang. Liu","doi":"10.2516/OGST/2020097","DOIUrl":"https://doi.org/10.2516/OGST/2020097","url":null,"abstract":"The cyclic methane hydrate production method was proposed with CO2 and N2 mixture stimulation. The cyclic production model was established based on actual hydrate reservoir parameters, accordingly, the production characteristics were analyzed, and a sensitivity analysis was conducted. The results show the following: (1) The depressurization mechanism is dominant in the cyclic production. CH4 production and CH4 hydrate dissociation can be greatly enhanced because the cyclic process can effectively reduce the partial pressure of CH4 (gas phase). However, there is a limited effect for CO2 storage. (2) Heat supply is essential for continuous hydrate dissociation. The CH4 hydrate dissociation degree is the highest in the near-wellbore area; in addition, the fluid porosity and effective permeability are significantly improved, and the reservoir temperature is obviously decreased. (3) The initial CH4 hydrate saturation, absolute permeability, intrinsic CO2 hydrate formation kinetic constant, injection time and production time can significantly influence the production performance of the natural gas hydrate reservoir.","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":"77649414","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
{"title":"Erratum to: 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/2021023","DOIUrl":"https://doi.org/10.2516/ogst/2021023","url":null,"abstract":"","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":"81125551","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}
Aiming at improving the stability of Supercritical CO2 (SC-CO2) foam in high temperature and salinity reservoirs, a kind of betaine surfactant, Hexadecyl Hydroxypropyl Sulfo Betaine (HHSB), was screened to stabilize SC-CO2 foam. The properties of SC-CO2 foam were improved at elevated temperature and pressure. The effects of surfactant concentration, temperature, pressure and salinity on film drainage rate were measured to explore the stability of SC-CO2 foam. The results showed that an increase of surfactant concentration, pressure and salinity can decrease film drainage rate and enhance the foam stability, which was attributed to the increase of surfactant adsorption at the gas–liquid interface. The performance of SC-CO2 foam formed by HHSB was improved and the tolerant temperature was up to 100 °C. 1-D core flooding experiments indicated that compared with Coinjection of Surfactant and Gas (CSG) method the SC-CO2 foam generated through Surfactant-Alternative-Gas (SAG) method had lower foam strength but better in-depth migration capacity. The high temperature and pressure 3-D sand showed that in Water-Alternative-Gas (WAG) case CO2 broke early through the high permeability layers. In SAG case, SC-CO2 foam can improve the macroscopic sweep efficiency by reducing the CO2 mobility.
{"title":"Static and flow behaviors of supercritical CO2 foam stabilized with betaine surfactant for mobility control application","authors":"Weitao Li, Kai Wang, Wenkuan Zheng","doi":"10.2516/ogst/2021040","DOIUrl":"https://doi.org/10.2516/ogst/2021040","url":null,"abstract":"Aiming at improving the stability of Supercritical CO2 (SC-CO2) foam in high temperature and salinity reservoirs, a kind of betaine surfactant, Hexadecyl Hydroxypropyl Sulfo Betaine (HHSB), was screened to stabilize SC-CO2 foam. The properties of SC-CO2 foam were improved at elevated temperature and pressure. The effects of surfactant concentration, temperature, pressure and salinity on film drainage rate were measured to explore the stability of SC-CO2 foam. The results showed that an increase of surfactant concentration, pressure and salinity can decrease film drainage rate and enhance the foam stability, which was attributed to the increase of surfactant adsorption at the gas–liquid interface. The performance of SC-CO2 foam formed by HHSB was improved and the tolerant temperature was up to 100 °C. 1-D core flooding experiments indicated that compared with Coinjection of Surfactant and Gas (CSG) method the SC-CO2 foam generated through Surfactant-Alternative-Gas (SAG) method had lower foam strength but better in-depth migration capacity. The high temperature and pressure 3-D sand showed that in Water-Alternative-Gas (WAG) case CO2 broke early through the high permeability layers. In SAG case, SC-CO2 foam can improve the macroscopic sweep efficiency by reducing the CO2 mobility.","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":"82061085","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}
Zhi Zhang, Jiawei Wang, Yanjun Li, Hexing Liu, Wen-bo Meng, Li Lei
The production of high temperature and high pressure gas wells fluctuates with time, which makes the pressure in the string fluctuate obviously and affects the service security of tubing string. In this paper, a pressure fluctuation model of the complete production process (including well opening, production and shut-in) is established, which is suitable for the multiphase flow of gas well. The pressure fluctuation in the tubing string is simulated. Influence of different well depth and average production on the fluctuating pressure of gas well are analyzed. According to the research results, if the well opening time top is 50 s, a transient pressure fluctuation is generated at wellhead and drops gradually. After the production starts, a pressure fluctuation will occur at wellhead 10~15 s after top, which is small and attenuates quickly. Pressure increases quickly in the shut-in moment and reaches the peak at tsh. Although pressure increases gradually with the well depth, fluctuation flattens out. The hysteresis phenomenon in appearance of pressure wave becomes more and more obvious with the well depth. The greater the production of gas well, the greater the pressure fluctuation in tubing string during well opening and production, but the value may not be very high. During well shut-in, the greater the production, the greater the pressure fluctuation and the value. Amplitude, angular frequency and value of phase are in direct proportion to pressure fluctuation degree and valve radix is in inverse proportion to pressure, which means that the greater the valve radix, the smaller the pressure.
{"title":"Research on the influence of production fluctuation of high-production gas well on service security of tubing string","authors":"Zhi Zhang, Jiawei Wang, Yanjun Li, Hexing Liu, Wen-bo Meng, Li Lei","doi":"10.2516/ogst/2021035","DOIUrl":"https://doi.org/10.2516/ogst/2021035","url":null,"abstract":"The production of high temperature and high pressure gas wells fluctuates with time, which makes the pressure in the string fluctuate obviously and affects the service security of tubing string. In this paper, a pressure fluctuation model of the complete production process (including well opening, production and shut-in) is established, which is suitable for the multiphase flow of gas well. The pressure fluctuation in the tubing string is simulated. Influence of different well depth and average production on the fluctuating pressure of gas well are analyzed. According to the research results, if the well opening time top is 50 s, a transient pressure fluctuation is generated at wellhead and drops gradually. After the production starts, a pressure fluctuation will occur at wellhead 10~15 s after top, which is small and attenuates quickly. Pressure increases quickly in the shut-in moment and reaches the peak at tsh. Although pressure increases gradually with the well depth, fluctuation flattens out. The hysteresis phenomenon in appearance of pressure wave becomes more and more obvious with the well depth. The greater the production of gas well, the greater the pressure fluctuation in tubing string during well opening and production, but the value may not be very high. During well shut-in, the greater the production, the greater the pressure fluctuation and the value. Amplitude, angular frequency and value of phase are in direct proportion to pressure fluctuation degree and valve radix is in inverse proportion to pressure, which means that the greater the valve radix, the smaller the pressure.","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":"82574840","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}
The major aim of the research is to investigate the ability of biogas as an alternative fuel for gasoline-powered Spark Ignition (SI) engine. In this study, biogas/gasoline fuel mixtures containing different ratios of biogas, gasoline, and biogas were tested in an SI engine with an increased compression ratio at different engine loads and constant engine speed. According to the comparison with gasoline, the utilization of biogas generally decreased the Brake Thermal Efficiency (BTE), while the Brake Specific Fuel Consumption (BSFC) rose. The lowest BTE and the highest BSFC were obtained with 100% biogas. Compared to gasoline, a decrease of 16.04% and an increase of 75.52% were observed, respectively. On the other hand, the use of biogas has improved all emissions. The best emission values were obtained with 100% biogas. Compared to gasoline, Carbon monoxide (CO), HydroCarbon (HC), and Nitrogen Oxide (NOx) emissions decreased by 56.42%, 63%, and 48.96%, respectively. Finally, according to the results of the combustion analysis, the peak pressures were reduced with the utilization of biogas, and the position of the peak pressure shifted by 2° to 3° Crank Angle (CA). Compared to gasoline, the lowest pressure was obtained with 100% biogas, resulting in a reduction of approximately 24.69%.
{"title":"Experimental study on the ability of different biogas level dual fuel spark ignition engine: Emission mitigation, performance, and combustion analysis","authors":"S. Şi̇mşek, S. Uslu, Hatice Simsek","doi":"10.2516/ogst/2021060","DOIUrl":"https://doi.org/10.2516/ogst/2021060","url":null,"abstract":"The major aim of the research is to investigate the ability of biogas as an alternative fuel for gasoline-powered Spark Ignition (SI) engine. In this study, biogas/gasoline fuel mixtures containing different ratios of biogas, gasoline, and biogas were tested in an SI engine with an increased compression ratio at different engine loads and constant engine speed. According to the comparison with gasoline, the utilization of biogas generally decreased the Brake Thermal Efficiency (BTE), while the Brake Specific Fuel Consumption (BSFC) rose. The lowest BTE and the highest BSFC were obtained with 100% biogas. Compared to gasoline, a decrease of 16.04% and an increase of 75.52% were observed, respectively. On the other hand, the use of biogas has improved all emissions. The best emission values were obtained with 100% biogas. Compared to gasoline, Carbon monoxide (CO), HydroCarbon (HC), and Nitrogen Oxide (NOx) emissions decreased by 56.42%, 63%, and 48.96%, respectively. Finally, according to the results of the combustion analysis, the peak pressures were reduced with the utilization of biogas, and the position of the peak pressure shifted by 2° to 3° Crank Angle (CA). Compared to gasoline, the lowest pressure was obtained with 100% biogas, resulting in a reduction of approximately 24.69%.","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":"85126388","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}
Capillarity refers to the phenomenon of fluids imbibing into fine pores or porous rocks and materials due to surface energy, through the action of capillary pressure. The capillary pressure causes the deformable interfaces formed between two phase fluids in contact with each other, such as a liquid and a vapor. Capillarity and its importance have been widely recognized in various fields, including civil engineering, soil science, hydrology, carbon storage, and petroleum engineering. More than a century ago, the classical Young–Laplace equation and Lucas-Washburn equation laid the foundation for the description of the capillary-driven flow of fluids in porous structures. With the rapid development of computational and experimental techniques, the research on capillarity is advancing at an unprecedented level and provides insight and opportunities for further effort in what is already a flourishing field of research. Four papers on capillarity in porous media are collected in this special issue and are summarized in the following paragraphs: In the paper “Shale adhesion force measurements via atomic force microscopy” [1], Mitiurev et al. used the AFM (Atomic Force Microscopy) technique to measure the adhesion force between cantilever and sample surface at nanoscale for shale. They used topographical analysis, SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive Spectroscopy) to accurately locate the measurement points on a sample surface and obtained consistent adhesion force measurements for quartz grain inclusions. The adhesion forces were determined to equal the water– air capillary pressure under the test conditions. These measurements and results have potential to create a path towards much higher accuracy–wettability measurements and consequently better reservoir-scale predictions and improved underground operations. In the paper “A modified cell-to-cell simulation model to determine the minimum miscibility pressure in tight/shale formations” [2], Sun and Li developed a new oil-gas minimum miscibility pressure calculation algorithm, which couples the effects of capillary pressure and confinement in the original cell-to-cell simulation model to predict the oil-gas minimum miscibility pressure in a confined space. By the algorithm, the effects of temperature, pore radius, and injection gas impurity on the confined oil gas minimum miscibility pressure calculations are studied in detail. They found that the oil gas minimum miscibility pressure is reduced in confined space and the degree of this reduction depends on the pore radius. For all the tested pore radii, the confined minimum miscibility pressure first increases and then decreases with an increasing temperature. Compared to pure carbon dioxide injection, the addition of methane in the injection gas increases the oil gas minimum miscibility pressure in confined nanopores. It is recommended to control the content of methane in the injection gas in order to achieve a more efficient g
毛细作用是指流体在毛细压力的作用下，由于表面能而进入细孔或多孔岩石、材料中的现象。毛细管压力使两相流体(如液体和蒸汽)之间形成可变形的界面。毛细现象及其重要性在土木工程、土壤科学、水文学、碳储存和石油工程等各个领域得到了广泛的认识。一个多世纪以前，经典的Young-Laplace方程和Lucas-Washburn方程为描述孔隙结构中毛细管驱动的流体流动奠定了基础。随着计算和实验技术的快速发展，对毛细现象的研究正以前所未有的水平向前推进，并为这一已经蓬勃发展的研究领域的进一步努力提供了见解和机会。本期特刊收集了关于多孔介质中毛细管作用的四篇论文，总结如下:在“Shale adhesion force measurements via atomic force microscopy”[1]这篇论文中，Mitiurev等人使用AFM (atomic force microscopy)技术在纳米尺度上测量了页岩悬臂梁与样品表面之间的粘附力。他们使用地形分析，SEM(扫描电子显微镜)和EDS(能量色散光谱)来精确定位样品表面上的测量点，并获得了石英颗粒包裹体的一致附着力测量值。在试验条件下，确定黏附力等于水-气毛细管压力。这些测量和结果有可能为更高精度的润湿性测量创造一条道路，从而更好地预测油藏规模，改善地下作业。在“致密/页岩储层最小混相压力的修正单元间模拟模型”一文中[2]，Sun和Li提出了一种新的油气最小混相压力计算算法，在原有的单元间模拟模型中耦合毛管压力和约束作用，预测密闭空间内的油气最小混相压力。通过该算法，详细研究了温度、孔隙半径和注入气体杂质对限定油气最小混相压力计算的影响。研究发现，油气最小混相压力在密闭空间内降低，且降低程度与孔隙半径有关。对于所有测试的孔隙半径，约束最小混相压力随温度的升高先增大后减小。与纯二氧化碳注入相比，注入气体中加入甲烷增加了油气在受限纳米孔内的最小混相压力。为了实现更高效的注气设计，建议控制注气中甲烷的含量。Gao等人在“烃类气液体系的毛细性和相迁移性”一文中[3]，采用x射线计算机微层析成像技术，在气泡点以下减压或注气时对孔隙层气液分布进行了三维成像。孔隙水平的气液分布可以直接获得气体的连通性，从而获得其流动性。采用基于晶格玻尔兹曼的流动模拟，直接从成像的气液分布计算各自(连通通道)的相对渗透率。当饱和度端点重新缩放到临界气饱和度时，气体相对渗透率遵循经典的非湿相排水相对渗透率曲线。液体相对渗透率与湿相吸胀和排水相对渗透率都是相容的。他们的研究为双组分系统的气体动力学提供了基本的见解，该系统低于气泡点压力，气体成核。Andersen在“毛细管末端效应稳态相对渗透率实验的解析建模与校正——改进的截距法、标度和一般毛细管数”一文中[4]，介绍了多孔介质中的毛细管作用:最新进展与挑战。安徒生、邹双梅(特约编辑)
{"title":"Capillarity in porous media: Recent advances and challenges","authors":"Jianchao Cai, P. Andersen, Shuangmei Zou","doi":"10.2516/ogst/2021059","DOIUrl":"https://doi.org/10.2516/ogst/2021059","url":null,"abstract":"Capillarity refers to the phenomenon of fluids imbibing into fine pores or porous rocks and materials due to surface energy, through the action of capillary pressure. The capillary pressure causes the deformable interfaces formed between two phase fluids in contact with each other, such as a liquid and a vapor. Capillarity and its importance have been widely recognized in various fields, including civil engineering, soil science, hydrology, carbon storage, and petroleum engineering. More than a century ago, the classical Young–Laplace equation and Lucas-Washburn equation laid the foundation for the description of the capillary-driven flow of fluids in porous structures. With the rapid development of computational and experimental techniques, the research on capillarity is advancing at an unprecedented level and provides insight and opportunities for further effort in what is already a flourishing field of research. Four papers on capillarity in porous media are collected in this special issue and are summarized in the following paragraphs: In the paper “Shale adhesion force measurements via atomic force microscopy” [1], Mitiurev et al. used the AFM (Atomic Force Microscopy) technique to measure the adhesion force between cantilever and sample surface at nanoscale for shale. They used topographical analysis, SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive Spectroscopy) to accurately locate the measurement points on a sample surface and obtained consistent adhesion force measurements for quartz grain inclusions. The adhesion forces were determined to equal the water– air capillary pressure under the test conditions. These measurements and results have potential to create a path towards much higher accuracy–wettability measurements and consequently better reservoir-scale predictions and improved underground operations. In the paper “A modified cell-to-cell simulation model to determine the minimum miscibility pressure in tight/shale formations” [2], Sun and Li developed a new oil-gas minimum miscibility pressure calculation algorithm, which couples the effects of capillary pressure and confinement in the original cell-to-cell simulation model to predict the oil-gas minimum miscibility pressure in a confined space. By the algorithm, the effects of temperature, pore radius, and injection gas impurity on the confined oil gas minimum miscibility pressure calculations are studied in detail. They found that the oil gas minimum miscibility pressure is reduced in confined space and the degree of this reduction depends on the pore radius. For all the tested pore radii, the confined minimum miscibility pressure first increases and then decreases with an increasing temperature. Compared to pure carbon dioxide injection, the addition of methane in the injection gas increases the oil gas minimum miscibility pressure in confined nanopores. It is recommended to control the content of methane in the injection gas in order to achieve a more efficient g","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":"86574670","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}
In this paper, we study the processes of mixing when using the technology of transportation of light oil products-sequential pumping by direct contact. Modeling of mixing processes is carried out taking into account the influence of parametric and thermodynamic factors. For numerical modeling, a software package was developed that allows not only modeling and calculating the parameters of the oil pipeline operation in real time with subsequent graphical visualization, but also comparing them with real data processed by operators at production facilities.
{"title":"Influence of accounting for thermodynamic processes on the processes of mixture formation during sequential pumping of petroleum products","authors":"I. M. Vanchugov, R. A. Shestakov","doi":"10.2516/OGST/2020100","DOIUrl":"https://doi.org/10.2516/OGST/2020100","url":null,"abstract":"In this paper, we study the processes of mixing when using the technology of transportation of light oil products-sequential pumping by direct contact. Modeling of mixing processes is carried out taking into account the influence of parametric and thermodynamic factors. For numerical modeling, a software package was developed that allows not only modeling and calculating the parameters of the oil pipeline operation in real time with subsequent graphical visualization, but also comparing them with real data processed by operators at production facilities.","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":"85343375","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}
Hongqiang Ma, Shengxun Wang, Yue-ting Xie, Xinmei Luo, Jianping Han
For insuring the safe operation of LNG heat exchanger in the Emergency Stop Operation Process (ESOP), a numerical method is proposed to investigate the stress of Plate-Fin Structures (PFS) in that. The relationship between stress of PFS and ESOP is analyzed in LNG heat exchanger. The results will be obtained that the maximum equivalent stress of PFS is greater at the initial stage of ESOP than that at the last stage when the HMR pressure is more than 5 MPa. The maximum equivalent stress increases with the equilibrium temperature when is greater than 180 K and reaches peak value at the last stage of ESOP. The maximum equivalent stress is larger at the last stage of ESOP than the other stage and increases with the equilibrium pressure. When the temperature difference is more than 5 K in the ESOP, the influence of that is obvious for the stress of PFS. In the ESOP, the equilibrium temperature and temperature difference should be controlled within 240 K and 5 K, respectively.
{"title":"The relationship between stress of plate-fin structures and emergency stop operation process in LNG heat exchanger","authors":"Hongqiang Ma, Shengxun Wang, Yue-ting Xie, Xinmei Luo, Jianping Han","doi":"10.2516/ogst/2021062","DOIUrl":"https://doi.org/10.2516/ogst/2021062","url":null,"abstract":"For insuring the safe operation of LNG heat exchanger in the Emergency Stop Operation Process (ESOP), a numerical method is proposed to investigate the stress of Plate-Fin Structures (PFS) in that. The relationship between stress of PFS and ESOP is analyzed in LNG heat exchanger. The results will be obtained that the maximum equivalent stress of PFS is greater at the initial stage of ESOP than that at the last stage when the HMR pressure is more than 5 MPa. The maximum equivalent stress increases with the equilibrium temperature when is greater than 180 K and reaches peak value at the last stage of ESOP. The maximum equivalent stress is larger at the last stage of ESOP than the other stage and increases with the equilibrium pressure. When the temperature difference is more than 5 K in the ESOP, the influence of that is obvious for the stress of PFS. In the ESOP, the equilibrium temperature and temperature difference should be controlled within 240 K and 5 K, respectively.","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":"86480950","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}
The optimisation of Post Carbon Capture (PCC) from a Waste-to-Energy plant has been studied using Kriging surrogate models trained from a set of rigorous process simulations. The surrogate models allow fast and efficient calculation of model responses required for the optimisation of operating parameters. Optimisation is performed using Differential Evolution (DE) requiring a vast amount of function calculations (>1000) which would be extremely time consuming if done with a rigorous process simulation model. It is found that for meeting a CO2 removal efficiency of 85% for a flue gas containing 12.6 mole % CO2 and a reboiler temperature limited to max. 120 °C, a L/G ratio of approx. 2.2 (kg/kg) is optimal. This is accompanied by a stripper/regenerator pressure of 1.85 bara, a temperature of the flue gas at the lower bound, a temperature approach of the lean amine entering the absorber of 6.5 °C (to the flue gas temperature), and a temperature approach in the L/R heat exchanger of 5 °C. The optimal lean and rich amine loading is approx. 0.21 and 0.52 (mole CO2/mole MEA).
{"title":"Optimisation of carbon capture from flue gas from a Waste-to-Energy plant using surrogate modelling and global optimisation","authors":"A. Andreasen","doi":"10.2516/ogst/2021036","DOIUrl":"https://doi.org/10.2516/ogst/2021036","url":null,"abstract":"The optimisation of Post Carbon Capture (PCC) from a Waste-to-Energy plant has been studied using Kriging surrogate models trained from a set of rigorous process simulations. The surrogate models allow fast and efficient calculation of model responses required for the optimisation of operating parameters. Optimisation is performed using Differential Evolution (DE) requiring a vast amount of function calculations (>1000) which would be extremely time consuming if done with a rigorous process simulation model. It is found that for meeting a CO2 removal efficiency of 85% for a flue gas containing 12.6 mole % CO2 and a reboiler temperature limited to max. 120 °C, a L/G ratio of approx. 2.2 (kg/kg) is optimal. This is accompanied by a stripper/regenerator pressure of 1.85 bara, a temperature of the flue gas at the lower bound, a temperature approach of the lean amine entering the absorber of 6.5 °C (to the flue gas temperature), and a temperature approach in the L/R heat exchanger of 5 °C. The optimal lean and rich amine loading is approx. 0.21 and 0.52 (mole CO2/mole MEA).","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":"89103724","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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