Effects of bacterial cell density and alternating microbial- and enzymolysis-enhanced oil recovery on oil displacement efficiency

2017 ◽  
Vol 327 ◽  
pp. 28-38 ◽  
Author(s):  
Hui Gao ◽  
Hangxian Lai ◽  
Junhui Zhang ◽  
Quanhong Xue
Keyword(s):  
Cell Density ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Bacterial Cell ◽  
Displacement Efficiency ◽  
Oil Displacement ◽  
Oil Displacement Efficiency

Mechanisms of Nanofluid Based Modification MoS2 Nanosheet for Enhanced Oil Recovery

2021 ◽  
Author(s):  
M. Qu
Keyword(s):  
Physicochemical Properties ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
High Efficiency ◽  
Emulsion Stability ◽  
Displacement Efficiency ◽  
Mos2 Nanosheets ◽  
Low Concentration ◽  
Oil Displacement ◽  
Oil Displacement Efficiency

Recently, much attention has been directed towards the applications of nanofluids for enhanced oil recovery (EOR). Here, amphiphilic molybdenum disulfide (KH550-MoS2) nanosheets were synthesized using a hydrothermal approach. The physicochemical properties and potential EOR of ultra-low concentration KH550-MoS2 nanofluids were systematically investigated under reservoir conditions at Changqing Oilfield (China) (temperature~55℃ and salinity~7.8×104 mg/L). Interfacial tension (IFT), wettability change, and emulsion stability were measured to evaluate the physicochemical properties of the KH550-MoS2 nanofluids. The results showed that ultra-low concentration of KH550-MoS2 nanofluid (50 mg/L) could decrease IFT to 2.6 mN/m, change the contact angle (CTA) from 131.2° to 51.7° and significantly enhance emulsion stability. Core flooding experiments were conducted to determine the dynamic adsorption loss law and the oil displacement efficiency of KH550-MoS2 nanofluid. The results indicated that the ratio of cumulative produced KH550-MoS2 nanosheets to the total injected KH550-MoS2 nanosheets (CNR) reached 91.5% during flooding in low permeability reservoirs. Moreover, ultra-low concentration KH550-MoS2 nanofluid can increase the oil displacement efficiency by 14% after water driven. This study shows the physicochemical properties of the KH550-MoS2 amphiphilic nanofluid and offers a novel high- efficiency amphiphilic nanofluid for EOR

Study on Nanoparticle Stabilized Emulsions for Chemical Flooding Enhanced Oil Recovery

2021 ◽  
Author(s):  
Youyi Zhu ◽  
Peng Yu ◽  
Jian Fan
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Emulsion Stability ◽  
Chemical Flooding ◽  
Displacement Efficiency ◽  
Nano Silica ◽  
Oil Displacement ◽  
Chemical Combination ◽  
Oil Displacement Efficiency ◽  
The Stability

Abstract Chemical flooding is one of enhanced oil recovery (EOR) methods. The primary mechanism of EOR of chemical flooding is interfacial tension reduction, mobility ratio improvement and wettability changes. Recent studies showed that enhancing emulsification performance was beneficial to improve oil displacement efficiency. The formation of Pickering emulsion by nanoparticles could greatly improve the emulsifying performance. Using nanoparticles stabilized emulsions for chemical EOR application is a novel method. In this study, six different types of nanoparticles were selected, including hydrophilic nano silica, modified nano silica, carbon nanotubes and bentonite, etc. The nanoparticle combine with petroleum sulfonate could form a stable emulsion. Particle wettability were measured by using contact angle measurement (OCA20). Emulsifying intensity index was measured for different nanoparticle-stabilized emulsions. The mechanisms of nanoparticle-stabilized emulsions and relationship between emulsion stability have been investigated. The influence of dispersant on nanoparticle-stabilized emulsions also has been investigated. Nanoparticles mainly play a role in improving the stability of emulsions while surfactant play a major role in enhancing the emulsifying dispersion. The wettability of solid particles was one of the most important factors that affects the stability of emulsions. Partial hydrophobic nanoparticles were much easier to form stable emulsions than hydrophilic nanoparticles. Nanoparticles could form a three-dimensional network structure, thereby the stability of the emulsion was improved. Use of surfactant to disperse nanoparticles could further improve the emulsion stability. Finally, three nanoparticles stabilized emulsion formulations were developed for chemical flooding EOR. Nanoparticle-stabilized emulsions could improve oil displacement efficiency in chemical combination flooding. This research was used to optimize chemical combination flooding formulation and has a guidance function for application of nanoparticles in chemical flooding EOR.

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 Enhanced Oil Recovery: Chemical Flooding

2021 ◽  
Author(s):  
Ahmed Ragab ◽  
Eman M. Mansour
Keyword(s):  
Interfacial Tension ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Recovery Phase ◽  
Mobility Ratio ◽  
Chemical Flooding ◽  
Sweep Efficiency ◽  
Oil Displacement ◽  
Remaining Oil ◽  
Oil Displacement Efficiency

The enhanced oil recovery phase of oil reservoirs production usually comes after the water/gas injection (secondary recovery) phase. The main objective of EOR application is to mobilize the remaining oil through enhancing the oil displacement and volumetric sweep efficiency. The oil displacement efficiency enhances by reducing the oil viscosity and/or by reducing the interfacial tension, while the volumetric sweep efficiency improves by developing a favorable mobility ratio between the displacing fluid and the remaining oil. It is important to identify remaining oil and the production mechanisms that are necessary to improve oil recovery prior to implementing an EOR phase. Chemical enhanced oil recovery is one of the major EOR methods that reduces the residual oil saturation by lowering water-oil interfacial tension (surfactant/alkaline) and increases the volumetric sweep efficiency by reducing the water-oil mobility ratio (polymer). In this chapter, the basic mechanisms of different chemical methods have been discussed including the interactions of different chemicals with the reservoir rocks and fluids. In addition, an up-to-date status of chemical flooding at the laboratory scale, pilot projects and field applications have been reported.

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.

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 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 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.

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.

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