scholarly journals Low-Abundance Dietzia Inhabiting a Water-Flooding Oil Reservoir and the Application Potential for Oil Recovery

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Peike Gao ◽  
Hongbo Wang ◽  
Guanxi Li ◽  
Ting Ma
Keyword(s):  
Oil Recovery ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Recovery Potential ◽  
Oil Displacement Efficiency ◽  
Application Potential ◽  
Nutrient Injection

With the development of molecular ecology, increasing low-abundance microbial populations were detected in oil reservoirs. However, our knowledge about the oil recovery potential of these populations is lacking. In this study, the oil recovery potential of low-abundance Dietzia that accounts for less than 0.5% in microbial communities of a water-flooding oil reservoir was investigated. On the one hand, Dietzia sp. strain ZQ-4 was isolated from the water-flooding reservoir, and the oil recovery potential was evaluated from the perspective of metabolisms and oil-displacing test. On the other hand, the strain has alkane hydroxylase genes alkB and P450 CYP153 and can degrade hydrocarbons and produce surfactants. The core-flooding test indicated that displacing fluid with 2% ZQ-4 fermentation broth increased 18.82% oil displacement efficiency, and in situ fermentation of ZQ-4 increased 1.97% oil displacement efficiency. Furthermore, the responses of Dietzia in the reservoir accompanied by the nutrient stimulation process was investigated and showed that Dietzia in some oil production wells significantly increased in the initial phase of nutrient injection and sharply decreased along with the continuous nutrient injection. Overall, this study indicates that Dietzia sp. strain has application potential for enhancing oil recovery through an ex situ way, yet the ability of oil recovery in situ based on nutrient injection is limited.

Mechanisms of Enhancing Recovery of the Superficial Heavy Oil Reservoir

2012 ◽  
Vol 550-553 ◽  
pp. 468-471
Author(s):  
Fu Sheng Zhang ◽  
Jian Ouyang ◽  
De Wei Wang ◽  
Xin Fang Feng ◽  
Li Qing Xu
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Water Flooding ◽  
Chemical Agent ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Heavy Oil Reservoir ◽  
Enhance Oil Recovery

The core displacement experiments show that displacement system containing chemical agent can enhance oil recovery by over 20% comparing to water flooding. Mechanisms by which chemical agent enhance oil recovery of heavy oil reservoir water flooding are: (1) improving mobility ratio by significantly decreasing viscosity of heavy oil, volumetric sweep efficiency is improved; (2) increasing capillary number by significantly decreasing oil-water interfacial tension, oil displacement efficiency is increased; (3) changing wettability of the rock surface from oil-wet to water-wet by significantly reducing the contact angle between displacement liquid and sandstone surface, capillary force is changed from the resistance force to the motive force, the residual oil is expelled from the small pores and the wall of pores, oil displacement efficiency is significantly increased.

scholarly journals The Study of Effect of Pore Structure on Oil Displacement Efficiency of Polymer Flooding

2016 ◽  
Vol 9 (1) ◽  
pp. 55-64
Author(s):  
Ma Wenguo
Keyword(s):  
Pore Structure ◽  
Oil Recovery ◽  
Water Flooding ◽  
Displacement Efficiency ◽  
Throat Radius ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Ct Technology ◽  
Micro Level ◽  
The Relationship

Characteristics of pore structure have an important influence on the development of water flooding. In order to improve the recovery rate, it is important to investigate the relationship between pore structure and oil displacement efficiency. The permeability of the artificial cores in this experiment is 189×10-3μm2, 741×10-3μm2and 21417×10-3μm2. We used the CT technology method to scan the pore structure of the three cores, and did oil displacement experiment to investigate the effect of pore structure on the oil displacement efficiency. The result shows that the pore and throat common affect oil displacement efficiency: the bigger the pore and throat radius, the better is the oil displacement efficiency; the smaller the pore and throat radius, the worse is the oil displacement efficiency. The experiment studied the influence of pore structure on oil displacement efficiency deep into microcosmic pore structure without damaging the core skeleton, thereby improving the basis of oil recovery from the micro level and the mechanism.

scholarly journals A Study on the Adjustment of Emulsification Degree to Interlayer Interference in Class III Reservoir

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Bin Huang ◽  
Tingge Dai ◽  
Hongjuan Liu ◽  
Cheng Fu ◽  
Tingting Zhu ◽  
...  
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Water Flooding ◽  
Chemical System ◽  
Emulsion System ◽  
Displacement Efficiency ◽  
Fractional Flow ◽  
Oil Displacement ◽  
Profile Control ◽  
Oil Displacement Efficiency

Emulsions play an important role in enhancing oil recovery during the reservoir flooding process. In order to reveal the profile control ability and the effect of adjustments to the interlayer interference during the migration of the emulsion in the porous media, a stable emulsion system and an alkali-surfactant-polymer (ASP) system were selected to simulate the underground emulsification process by verifying influencing factors of the emulsion. A parallel-core displacement experiment was used to investigate the oil displacement efficiency and the difference of fractional flow in each layer under different emulsification degrees and different permeability contrasts. The results indicate that the stability of the emulsion is related to the shearing strength, the water content, and the type and concentration of chemical system. The oil displacement efficiency of emulsion flooding is better than that of ASP flooding. For parallel core with an average permeability of 40 mD and a permeability contrast of 2, the emulsion flooding can enhance oil recovery by 21.16% compared to water flooding. With increasing permeability contrast, the oil recovery percent of emulsion flooding will further increase. The emulsion system has good profile control ability. Within a certain range, the stronger the heterogeneity of porous media, the better the effect of emulsification on the adjustment of the interlayer interference.

Research and Application of Multi-Slug and Equi-Fluidity Oil Displacement Mechanism

2015 ◽  
Vol 733 ◽  
pp. 43-46
Author(s):  
Jiang Min Zhao ◽  
Tian Ge Li
Keyword(s):  
Pressure Gradient ◽  
Flow Rate ◽  
Oil Recovery ◽  
Recovery Rate ◽  
Actual Situation ◽  
Displacement Efficiency ◽  
Displacement Method ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Swept Volume

In this paper, several aspects of the improvement of the oil recovery were analyzed theoretically based on the mechanism that equi-fluidity enhances the pressure gradient. These aspects include the increase of the flow rate and the recovery rate, of the swept volume, and of the oil displacement efficiency. Also, based on the actual situation, the author designed the oil displacement method with gathered energy equi-fluidity, realizing the expectation of enhancing oil recovery with multi-slug and equi-fluidity oil displacement method.

scholarly journals Differences of microscopic seepage mechanisms of water flooding and polymer flooding and prediction models of final oil recovery for conglomerate reservoir

2019 ◽  
Vol 74 ◽  
pp. 13
Author(s):  
Fengqi Tan ◽  
Changfu Xu ◽  
Yuliang Zhang ◽  
Gang Luo ◽  
Yukun Chen ◽  
...  
Keyword(s):  
Pore Structure ◽  
Polymer Solution ◽  
Oil Recovery ◽  
Particle Surface ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Residual Oil ◽  
Displacement Efficiency ◽  
Oil Saturation ◽  
Oil Displacement Efficiency

The special sedimentary environments of conglomerate reservoir lead to pore structure characteristics of complex modal, and the reservoir seepage system is mainly in the “sparse reticular-non reticular” flow pattern. As a result, the study on microscopic seepage mechanism of water flooding and polymer flooding and their differences becomes the complex part and key to enhance oil recovery. In this paper, the actual core samples from conglomerate reservoir in Karamay oilfield are selected as research objects to explore microscopic seepage mechanisms of water flooding and polymer flooding for hydrophilic rock as well as lipophilic rock by applying the Computed Tomography (CT) scanning technology. After that, the final oil recovery models of conglomerate reservoir are established in two displacement methods based on the influence analysis of oil displacement efficiency. Experimental results show that the seepage mechanisms of water flooding and polymer flooding for hydrophilic rock are all mainly “crawling” displacement along the rock surface while the weak lipophilic rocks are all mainly “inrushing” displacement along pore central. Due to the different seepage mechanisms among the water flooding and the polymer flooding, the residual oil remains in hydrophilic rock after water flooding process is mainly distributed in fine throats and pore interchange. These residual oil are cut into small droplets under the influence of polymer solution with stronger shearing drag effect. Then, those small droplets pass well through narrow throats and move forward along with the polymer solution flow, which makes enhancing oil recovery to be possible. The residual oil in weak lipophilic rock after water flooding mainly distributed on the rock particle surface and formed oil film and fine pore-throat. The polymer solution with stronger shear stress makes these oil films to carry away from particle surface in two ways such as bridge connection and forming oil silk. Because of the essential attributes differences between polymer solution and injection water solution, the impact of Complex Modal Pore Structure (CMPS) on the polymer solution displacement and seepage is much smaller than on water flooding solution. Therefore, for the two types of conglomerate rocks with different wettability, the pore structure is the main controlling factor of water flooding efficiency, while reservoir properties oil saturation, and other factors have smaller influence on flooding efficiency although the polymer flooding efficiency has a good correlation with remaining oil saturation after water flooding. Based on the analysis on oil displacement efficiency factors, the parameters of water flooding index and remaining oil saturation after water flooding are used to establish respectively calculation models of oil recovery in water flooding stage and polymer flooding stage for conglomerate reservoir. These models are able to calculate the oil recovery values of this area controlled by single well control, and further to determine the oil recovery of whole reservoir in different displacement stages by leveraging interpolation simulation methods, thereby providing more accurate geological parameters for the fine design of displacement oil program.

Study on Influence of Injection Method on the Effect of Oil Displacement of Nanometer Microspheres

2013 ◽  
Vol 734-737 ◽  
pp. 1272-1275
Author(s):  
Ji Hong Zhang ◽  
Zhi Ming Zhang ◽  
Xi Ling Chen ◽  
Qing Bin He ◽  
Jin Feng Li
Keyword(s):  
Oil Recovery ◽  
Experimental Result ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Profile Control ◽  
Oil Displacement Efficiency ◽  
Injection Methods ◽  
The One ◽  
Deep Profile ◽  
Enhance Oil Recovery

Nanometer microspheres injection is a new deep profile control technology. Nanometer microspheres could inflate with water, resulting in plugging step by step in reservoirs, which could improve the swept efficiency in the reservoir and enhance oil recovery. By using non-homogeneous rectangular core, oil displacement efficiency experiment was conducted for studying the influence of different injection methods on the effect of injection nanometer microspheres. The experimental result shows that, compared with development effect of single-slug injection or triple-slug injection, the one of double-slug injection is better. Nanometer microspheres can enhance oil recovery significantly in medium and low permeability reservoir.

scholarly journals The Research and Application of Microbial Degradation Technology on Heavy Oil Reservoir in Huabei Oilfield

2018 ◽  
Vol 38 ◽  
pp. 01054
Author(s):  
Guan Wang ◽  
Rui Wang ◽  
Yaxiu Fu ◽  
Lisha Duan ◽  
Xizhi Yuan ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
High Surface ◽  
Effective Rate ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Displacement Efficiency ◽  
Oil Viscosity ◽  
Reservoir Conditions ◽  
Heavy Oil Reservoir

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.

scholarly journals Study on the Flow Mechanism of Shale Oil with Different Injection Media

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lanlan Yao ◽  
Zhengming Yang ◽  
Haibo Li ◽  
Bo Cai ◽  
Chunming He ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Bohai Bay ◽  
Shale Oil ◽  
Formation Water ◽  
Displacement Efficiency ◽  
Pore Throat ◽  
Tight Sandstone ◽  
Oil Displacement ◽  
Oil Displacement Efficiency ◽  
Effective Development

Chinese shale oil has high recoverable resources and great development potential. However, due to the limitation of development technology, the recovery rate of shale oil is not high. In this paper, the effects of different injection media on the development of shale oil reservoirs in Dongying formation, Qikou depression, Huanghua depression, and Bohai bay basin, were studied by means of imbibition and nitrogen flooding. Combining nuclear magnetic resonance (NMR) technology with imbibition and gas displacement experiments, the mechanism of shale injected formation water, active water (surfactant), and nitrogen was reproduced. The displacement process of crude oil under different injection media and injection conditions was truly demonstrated, and the relationship between different development methods and the pore boundaries used was clarified. A theoretical basis for the effective development of shale oil was provided. At the same time, Changqing tight oil cores with similar permeability to Dagang shale oil cores were selected for comparison. The results showed that, as the imbibition time of shale samples increased, the imbibition efficiency increased. Pores with T2 < 10 ms contributed the most to imbibition efficiency, with an average contribution greater than 90%. 10 ms < T2 < 100 ms and more than 100 ms pores contributed less to imbibition efficiency. Active water can change the wettability of shale, increase its hydrophilicity, and improve the efficiency of imbibition. The imbibition recovery ratio of injected active water was 17.56% higher than that of injected formation water. Compared with tight sandstone with similar permeability, the imbibition efficiency of shale was lower. As the nitrogen displacement pressure increased, the oil displacement efficiency also increased. The higher the shale permeability was, the greater the displacement efficiency would be. T2 > 100 ms pore throat of shale contributed to the main oil displacement efficiency, with an average oil displacement efficiency contribution of 63.16%. And the relaxation interval 10 < T2 < 100 ms pore throat displacement efficiency contributed to 28.27%. T2 < 10 ms pore throat contributed the least to the oil displacement efficiency, with an average oil displacement efficiency contribution of 8.58%. Compared with tight sandstone with similar permeability, shale had lower oil displacement efficiency. The findings of this study can help for better understanding of the influence of different injection media on shale oil recovery effect.

Study on Ultimate Recovery Factor and Oil Recovery Rate of Water-Flooded Sandstone Oil Fields in Eastern South China Sea

2021 ◽  
Author(s):  
Qi Xiong ◽  
Zhenghe Yan ◽  
Li Li ◽  
Yong Yang ◽  
Yahui Wang ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Oil Recovery ◽  
Recovery Rate ◽  
Optimal Recovery ◽  
Oil Fields ◽  
Displacement Efficiency ◽  
China Sea ◽  
Oil Displacement ◽  
Oil Displacement Efficiency

Abstract Under the natural energy development of Marine sandstone oil fields in the east of the South China Sea, the recovery degree of some oil fields has exceeded 65%, and the production capacity is still strong. The high-speed development model does not seem to have an adverse effect on oil recovery. Based on the existing knowledge and technical conditions, it is difficult to analyze and predict the final recovery rate of oil field. The reasonable boundary between the oil rate and recovery is also unclear. In this study, we investigate the correlation between oil rate and recovery rate by experiment and field practice. Based on the microscopic displacement experiment, the variation rules of phase permeability, wettability, residual oil, displacement efficiency and sweep volume of different displacement multiples are studied. The variation law of oil rate and recovery under different fluidity and well control conditions is studied by mathematical statistics according to the production dynamic data. Thus, the influencing factors and percolation mechanism of the optimal recovery under high multiples water flooding are clarified, and the relationship between the reasonable oil rate and optimal recovery under different reservoir conditions is formed. Micro experiments show that high multiples water flooding can improve the reservoir property, change wettability of rocks, reduce the residual oil saturation, improve oil displacement efficiency and the final oil displacement efficiency can reach 80%. Statistical research shows that when the oil recovery rate is less than 10%, the recovery rate increases with the increase of oil rate. For bottom water reservoirs, the recovery rate is recommended to be no more than 8%. The paper innovatively studies the correlation between the reasonable oil rate and optimal recovery in Marine sandstone oilfield from microscopic experimental analysis and macroscopic statistical research. The research results effectively guide the oil field production practice of more than 200 Wells in more than 20 oil fields in the eastern South China Sea in 2019, with a cumulative oil increase of more than 5 million barrels. And it has important guiding significance to the efficient and economical development of Marine sandstone oilfield.

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