scholarly journals Study on the variation of rock pore structure after polymer gel flooding

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 32-38
Author(s):  
Dong Zhang ◽  
Jianguang Wei ◽  
Xinren Fang
Keyword(s):  
Pore Structure ◽  
Oil Recovery ◽  
Control Mechanism ◽  
Polymer Gels ◽  
Polymer Gel ◽  
Reservoir Water ◽  
The Core ◽  
Profile Control ◽  
Enhance Oil Recovery ◽  
Micro Structures

AbstractPolymer gels have received an increasing attention as profile control agents in the heterogeneous reservoir water-flooded layers. The article focus on the profile control mechanism of polymer gels by plugging macropore. The micro-structures of polymer gel and pore were characterized by scanning electron microscopy (SEM). And the core displacement equipment was used to evaluate the properties of plugging properties. The variation of pore structure is measured by SEM, mercury intrusion meter and nuclear magnetic resonance instrument. Investigation results show that the molecules form a network structure with many dense layers after 15 days of cross-linking reaction, which results in the increase of the viscosity of the system from 15.3 to 6325 mPa‧s. After the polymer gel forms a micelle at the middle end of the core and blocks the pores, the plugging rate of the core reaches 99.2%. The results obtained in this paper reveal the mechanism of plugging characteristics of polymer gels, and further prove the great potential of polymer gels to enhance oil recovery in oilfields.

Research on deep profile control technology of polymer gel with low hydrolytic degree

2019 ◽  
Vol 9 (9) ◽  
pp. 1087-1091 ◽  
Author(s):  
Dong Zhang ◽  
Jianguang Wei ◽  
Runnan Zhou ◽  
Haiqiao Xu
Keyword(s):  
Oil Recovery ◽  
Polymer Concentration ◽  
Gelation Time ◽  
Polymer Gels ◽  
Degree Of Hydrolysis ◽  
Crosslinking Reaction ◽  
Polymer Gel ◽  
Profile Control ◽  
Deep Profile ◽  
Enhance Oil Recovery

Polymer gels have attracted increasing interest as profile control agent to control water content and enhance oil recovery in heterogeneous reservoirs. However, retarding the gel crosslinking reaction of polymer and making it farther in the reservoir has become a difficulty in deep profile control. In this article, polyacrylamide with low degree of hydrolysis was prepared to react slowly with chromium ion to form gel, which was used for adjusting water injection profile. The microstructure of polymer gel was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. Core displacement experiments were used to evaluate the profile adjustment capability of polymer gels. It was found that the gel prepared by crosslinking the 5% polyacrylamide with chromium acetate can retard gelation time to 30 days in comparison with the conventional polymer gels when the polymer concentration reached to 1500 mg/L. The gel can form a regular spatial network which increases the viscosity from 80.2 to 6578 mPa · s. The results obtained by the core flooding experiment prove that the polymer gel has good profile control ability and further demonstrate the future potential of polymer gel to enhance oil recovery.

Development of Polymer Gel Plugging Removal Agent in Suizhong 361 Oilfield

2013 ◽  
Vol 860-863 ◽  
pp. 1026-1029 ◽  
Author(s):  
Guang Sheng Cao ◽  
Lei Wang ◽  
Gui Long Wang
Keyword(s):  
Oil Recovery ◽  
Control Mechanism ◽  
Practical Significance ◽  
Polymer Gel ◽  
High Permeability ◽  
Special Situation ◽  
Profile Control ◽  
The Cost ◽  
New Formula ◽  
Continuous Injection

Suizhong 361 offshore oilfield has applied polymer gel to profile control operations. With the continuous injection of the polymer gel, packers had not been put down in the whole of profile job because of the special situation of offshore oilfield. It has resulted that the polymer gel not only blocked layer segments of high permeability, but also blocked the rest lays. This situation makes the subsequent construction impossible and fails to reach the purpose of profile control. Therefore an effective blocking remover is necessary to break down reservoirs and open the low permeability layers, so that the polymer gel will be continued injecting into the reservoirs for subsequent construction. The purpose of profile will be achieved. Based on the actual blocking situation of Suizhong 361 oilfield, as well as the blockage removing mechanism of plugging removal agent and the profile control mechanism of polymer gel, a new plugging removal agent formula has been developed by screening and optimizing the type and mass concentration of blocking removal agent. Research shows that degradation rate of the new formula has reached above 90%, which has an important practical significance for enhancing oil recovery and reducing the cost of oil production.

Polymer Gelled Technology to Improve Sweep Efficiency in Enhanced Oil Recovery: A Literature Review

2015 ◽  
Vol 1113 ◽  
pp. 690-694 ◽  
Author(s):  
Norfarisha Achim ◽  
Nur Hashimah Alias ◽  
Nurul Aimi Ghazali ◽  
Miradatul Najwa Muhd Rodhi ◽  
Tengku Amran Tengku Mohd ◽  
...  
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Polymer Gels ◽  
Fluid Injection ◽  
Potential Candidate ◽  
Polymer Gel ◽  
Excellent Performance ◽  
Sweep Efficiency ◽  
Enhance Oil Recovery ◽  
Permeability Modification

This article is an overview of the use of polymer gelled technology to improve sweep efficiency in enhanced oil recovery. Recent progress use polymer types, Polyacrylamide and polysaccharide to be applied in enhanced oil recovery (EOR). A lot of researchers concluded that polymer gel stability must be maintained to ensure excellent performance in sweep efficiency. The application of polymer gels in permeability modification to improve volumetric sweep efficiency of fluid injection processes showed fruitful efforts as it can be a potential candidate to enhance oil recovery as compared to other technologies.

scholarly journals Investigation on the effect of active-polymers with different functional groups for EOR

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 61-68
Author(s):  
Dong Zhang ◽  
Jian Guang Wei ◽  
Run Nan Zhou
Keyword(s):  
Functional Groups ◽  
Oil Recovery ◽  
Molecular Size ◽  
Type I ◽  
Cleaning Efficiency ◽  
Sweep Efficiency ◽  
Profile Control ◽  
Branched Chain ◽  
Swept Volume ◽  
Enhance Oil Recovery

AbstractActive-polymer attracted increasing interest as an enhancing oil recovery technology in oilfield development owing to the characteristics of polymer and surfactant. Different types of active functional groups, which grafted on the polymer branched chain, have different effects on the oil displacement performance of the active-polymers. In this article, the determination of molecular size and viscosity of active-polymers were characterized by Scatterer and Rheometer to detect the expanded swept volume ability. And the Leica microscope was used to evaluate the emulsifying property of the active-polymers, which confirmed the oil sweep efficiency. Results show that the Type I active-polymer have a greater molecular size and stronger viscosity, which is a profile control system for expanding the swept volume. The emulsification performance of Type III active-polymer is more stable, which is suitable for improving the oil cleaning efficiency. The results obtained in this paper reveal the application prospect of the active-polymer to enhance oil recovery in the development of oilfields.

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 Improving Oil Recovery of the Heterogeneous Low Permeability Reservoirs by Combination of Polymer Hydrolysis Polyacrylamide and Two Highly Biosurfactant-Producing Bacteria

2021 ◽  
Vol 14 (1) ◽  
pp. 423
Author(s):  
Shuwen Xue ◽  
Yanhong Zhao ◽  
Chunling Zhou ◽  
Guangming Zhang ◽  
Fulin Chen ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Low Permeability ◽  
Bacterial Fermentation ◽  
The Core ◽  
Oil Displacement ◽  
Polymer Hydrolysis ◽  
Enhance Oil Recovery ◽  
Low Permeability Reservoirs ◽  
Microbial Flooding ◽  
Poly Acrylamide

Polymer hydrolysis polyacrylamide and microbes have been used to enhance oil recovery in many oil reservoirs. However, the application of this two-method combination was less investigated, especially in low permeability reservoirs. In this work, two bacteria, a rhamnolipid-producing Pseudomonas aeruginosa 8D and a lipopeptide-producing Bacillus subtilis S4, were used together with hydrolysis poly-acrylamide in a low permeability heterogeneous core physical model. The results showed that when the two bacterial fermentation liquids were used at a ratio by volumeof 1:3 (v:v), the mixture showed the optimal physicochemical properties for oil-displacement. In addition, the mixture was stable under the conditions of various temperature (20–70 °C) and salinity (0–22%). When the polymer and bacteria were mixed together, it had no significant effects in the viscosity of polymer hydrolysis polyacrylamide and the viability of bacteria. The core oil-displacement test displayed that polymer hydrolysis polyacrylamide addition followed by the bacterial mixture injection could significantly enhance oil recovery. The recovery rate was increased by 15.01% and 10.03%, respectively, compared with the sole polymer hydrolysis polyacrylamide flooding and microbial flooding. Taken together, these results suggest that the strategy of polymer hydrolysis poly-acrylamide addition followed by microbial flooding is beneficial for improving oil recovery in heterogeneous low permeability reservoirs.

scholarly journals Application Potential Analysis of Enhanced Oil Recovery by Biopolymer-Producing Bacteria and Biosurfactant-Producing Bacteria Compound Flooding

2019 ◽  
Vol 9 (23) ◽  
pp. 5119
Author(s):  
Yongqiang Bi ◽  
Jianlong Xiu ◽  
Ting Ma
Keyword(s):  
Oil Recovery ◽  
Laboratory Experiments ◽  
Fermentation Broth ◽  
Enterobacter Cloacae ◽  
Core Flooding ◽  
Heterogeneous Reservoirs ◽  
The Core ◽  
Profile Control ◽  
Application Potential ◽  
Degradation Medium

To study the feasibility of polymer-producing bacteria Enterobacter cloacae (E. cloacae) FY-07 and surfactant-producing bacteria Pseudomonas aeruginosa WJ-1 combined profile control and flooding, the compatibility of FY-07 and WJ-1 was evaluated using laboratory experiments. The results showed that the growth and metabolism of WJ-1 was not significantly affected by the FY-07 in the degradation medium, and the surface tension of fermentation broth was reduced from 70 mN/m to 30 mN/m. FY-07 enhanced the degradation of WJ-1, increasing the ratio of C14- to C15+ from 0.37 to 0.67. The core-flooding experiments indicated the oil recovery of 17.4% when both FY-07 and WJ-1 were injected into the system, as against to 10.4% and 7.9% for FY-07 and WJ-1, respectively, when injected alone. The results demonstrate a good compatibility between the FY-07 and WJ-1 strains and highlight the application potential of stain FY-07 and strain WJ-1 compound flooding for enhancing the oil recovery in heterogeneous reservoirs.

Evaluation and Application of Endogenous Microorganism Activator in Reservoir after Chemical Flooding

2014 ◽  
Vol 1051 ◽  
pp. 404-409
Author(s):  
Jian Jun Le ◽  
Ji Yuan Zhang ◽  
Lu Lu Bai ◽  
Rui Wang ◽  
Zhao Wei Hou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Oil Recovery ◽  
Physical Simulation ◽  
Chemical Flooding ◽  
Core Flooding ◽  
Simulation Experiments ◽  
The Core ◽  
Enhance Oil Recovery ◽  
Growth And Reproduction

To further enhance oil recovery in reservoir after chemical flooding, an efficient activator formulation for promoting metabolism of endogenous microorganism was researched. Changes in community structure, growth and metabolites of endogenous microorganism were analyzed by methods of aerogenic experiments, physical simulation experiments, electron microscopy scanning (SEM), T-RFLP and Pyrophosphate sequencing. To evaluate whether endogenous microorganism activator screened in laboratory could activate endogenous microorganisms and enhance oil recovery in reservoirs after polymer flooding. The flooding effect and mechanism were studied, and this activator was used in a testing well group in Daqing oilfield. The results of the aerogenic experiments showed that the activator could activate the endogenous microorganisms in the injected water and make them produce a lot of biogas. The pressurized gas reached 2MPa after 60d static culture of activator in a high pressure vessel. The results showed that the activator could activate the endogenous microorganisms in the injected sewage and make them have a lot of growth and reproduction in the core and physical simulation of natural core flooding experiment. In the field test,the incremental oil production was 5957 t while the water content declined by 2.2% after injecting the activator, which provides an effective way to further enhance oil recovery in reservoir after chemical flooding.

scholarly journals Experimental Study on Expansion Characteristics of Core-Shell and Polymeric Microspheres

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Pengxiang Diwu ◽  
Baoyi Jiang ◽  
Jirui Hou ◽  
Zhenjiang You ◽  
Jia Wang ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Early Stage ◽  
Average Diameter ◽  
Control Agent ◽  
Field Application ◽  
Experimental Results ◽  
Core Shell ◽  
The Core ◽  
Profile Control ◽  
Polymeric Microsphere

Traditional polymeric microsphere has several technical advantages in enhancing oil recovery. Nevertheless, its performance in some field application is unsatisfactory due to limited blockage strength. Since the last decade, novel core-shell microsphere has been developed as the next-generation profile control agent. To understand the expansion characteristic differences between these two types of microspheres, we conduct size measurement experiments on the polymeric and core-shell microspheres, respectively. The experimental results show two main differences between them. First, the core-shell microsphere exhibits a unimodal distribution, compared to multimodal distribution of the polymeric microsphere. Second, the average diameter of the core-shell microsphere increases faster than that of the polymeric microsphere in the early stage of swelling, that is, 0–3 days. These two main differences both result from the electrostatic attraction between core-shell microspheres with different hydration degrees. Based on the experimental results, the core-shell microsphere is suitable for injection in the early stage to block the near-wellbore zone, and the polymeric microsphere is suitable for subsequent injection to block the formation away from the well. A simple mathematical model is proposed for size evolution of the polymeric and core-shell microspheres.

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