scholarly journals Influence of the Interfacial Properties on the Stability of Water in Heavy Oil Emulsions in Thermal Recovery Process

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yongtao Sun ◽  
Zhaomin Li

Under the conditions of thermal oil recovery, the heavy oil in a reservoir usually exists in the form of W/O emulsion with high water content, which has significant effect on oil recovery performance. The most important parameter on the stability of W/O emulsion is interfacial properties. Thus, in order to investigate the effect of interfacial properties on the stability of W/O emulsion in a heavy oil reservoir at elevated temperatures, experiments have been conducted to generate various emulsions with variations in the temperature; stirring rate; contents of asphaltene, resin, and wax of the simulated heavy oil; and water salinity based on a target heavy oil reservoir in China. Then, the properties of the W/O emulsions include viscosity, interfacial viscosity (IFV), interfacial tension (IFT), and dehydration rate; the microscopic morphologies are measured as well. The experimental results show evidently stable W/O emulsion of heavy oil and water generated in thermal processes due to the stable, thick, and indistinct interface between heavy oil and water, where the active molecules of asphaltene and resin are accumulated. The interface connects the central large droplet and the surrounding small droplets tightly. The results also indicate the size of the central droplet, and the indistinct interface can be enlarged with increasing temperature and increasing stirring rate. Compared to resin, it is noted that the larger asphaltene molecules have stronger connection because of their stronger intermolecular force, larger IFV, and less IFT. At the same time, the stability of W/O emulsion will be strengthened with increasing temperature and stirring rate and gradually weakened with increasing salinity. In conclusion, the stability of water in heavy oil emulsion is mainly related to the large interfacial viscosity of the interface with much more heavy components such as asphaltene and resin compared to thin oil.

2021 ◽  
Vol 888 ◽  
pp. 111-117
Author(s):  
Yi Zhao ◽  
De Yin Zhao ◽  
Rong Qiang Zhong ◽  
Li Rong Yao ◽  
Ke Ke Li

With the continuous exploitation of most reservoirs in China, the proportion of heavy oil reservoirs increases, and the development difficulty is greater than that of conventional reservoirs. In view of the important subject of how to improve the recovery factor of heavy oil reservoir, the thermal recovery technology (hot water flooding, steam flooding, steam assisted gravity drainage SAGD and steam huff and puff) and cold recovery technology (chemical flooding, electromagnetic wave physical flooding and microbial flooding) used in the development of heavy oil reservoir are summarized. The principle of action is analyzed, and the main problems restricting heavy oil recovery are analyzed The main technologies of heavy oil recovery are introduced from the aspects of cold recovery and hot recovery. Based on the study of a large number of literatures, and according to the development trend of heavy oil development, suggestions and prospects for the future development direction are put forward.


2019 ◽  
Author(s):  
Zhaopeng Yang ◽  
Xingmin Li ◽  
Heping Chen ◽  
Hariharan Ramachandran ◽  
Yang Shen ◽  
...  

2013 ◽  
Vol 807-809 ◽  
pp. 2624-2628
Author(s):  
Qing Feng Cui ◽  
Li Na Yi ◽  
Han Ping Dong

The feasibility of enhancing oil recovery in Xinjiang oilfield with heavy oil reservoir was studied. The results showed that main microbial populations in the reservoir were saprophytic, hydrocarbon-oxidizing, nitrate-reducing bacteria, sulfate-reducing bacteria, and fermentative. Given optimized carbon and nitrogen sources, the indigenous microorganisms generated gases, which mostly were CO2, and amount of gases could reach 1.3 times volume as nutrient solution. The effect of MEOR was evaluated by a sand pack experiment, and the oil recovery was 9.5%. The test with the injection of nutrient and air was carried out. Field performance monitoring and product ion tracking results showed: 1the indigenous microorganisms were activated with the number increased 2-3, and microbial population structure changed apparently; 2The content of CO2 and CH4 in the gas of oil well changed slightly; 3the properties formation water were changed, the content of HCO3- in formation water varied greatly, and emulsion were found. 4Although Indigenous Microbial Flooding Technology may be a potential technique for the development of oilfields, that biogas generated by microbes is not the primary mechanism of Indigenous Microbial Flooding Technology is determined.


2018 ◽  
Vol 38 ◽  
pp. 01054
Author(s):  
Guan Wang ◽  
Rui Wang ◽  
Yaxiu Fu ◽  
Lisha Duan ◽  
Xizhi Yuan ◽  
...  

Mengulin sandstone reservoir in Huabei oilfield is low- temperature heavy oil reservoir. Recently, it is at later stage of waterflooding development. The producing degree of water flooding is poor, and it is difficult to keep yield stable. To improve oilfield development effect, according to the characteristics of reservoir geology, microbial enhanced oil recovery to improve oil displacement efficiency is researched. 2 microbial strains suitable for the reservoir conditions were screened indoor. The growth characteristics of strains, compatibility and function mechanism with crude oil were studied. Results show that the screened strains have very strong ability to utilize petroleum hydrocarbon to grow and metabolize, can achieve the purpose of reducing oil viscosity, and can also produce biological molecules with high surface activity to reduce the oil-water interfacial tension. 9 oil wells had been chosen to carry on the pilot test of microbial stimulation, of which 7 wells became effective with better experiment results. The measures effective rate is 77.8%, the increased oil is 1,093.5 tons and the valid is up to 190 days.


2012 ◽  
Vol 594-597 ◽  
pp. 2438-2441 ◽  
Author(s):  
Shi Jun Huang ◽  
Ping Hu ◽  
Qiu Li

In this paper, employing reservoir simulation and mathematical analysis methods, considering typical heavy oil reservoir and fluid thermal properties, the heating and producing shape of thermal recovery with horizontal well for different heavy oil reservoirs including ordinary, extra and super heavy oil are investigated based on the modification of thermal recovery parameters of different viscosity. By introducing heating radius and producing radius and considering the coupling effect of temperature, pressure and oil saturation fields, a quantitative expression between heating radius/producing radius and oil viscosity, formation thickness is presented, so is the impact of oil viscosity on the heating radius. Results shows that for Cyclic Steam Stimulation, the producing radius of horizontal well is bigger than its heating radius for light oil, both of which, however, shrink with higher viscosity. Beyond a critical viscosity, where the heating radius equals to the producing radius, the heating radius of horizontal well would be bigger than its producing radius. More over, the critical viscosity shows tight relationship to the formation thickness.


2014 ◽  
Vol 1015 ◽  
pp. 308-311
Author(s):  
Jia Mei Geng

With the deepening of the degree of oil exploration and development, as well as the rapid growth of world demand for oil, heavy oil reservoir development is becoming increasingly important in the position in oil exploration. For reserves a great deal of ultra heavy oil reservoir at present, conventional thermal recovery technology is difficult to obtain a good development effect. In this study we use computational fluid dynamics software ANYSY CFX to analyze the impact of horizontal and vertical pressure gradient on the seepage velocity difference..


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