scholarly journals Viral Abundance and Diversity of Production Fluids in Oil Reservoirs

2020 ◽  
Vol 8 (9) ◽  
pp. 1429
Author(s):  
Liangcan Zheng ◽  
Xiaolong Liang ◽  
Rongjiu Shi ◽  
Ping Li ◽  
Jinyi Zhao ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Community Dynamics ◽  
Diversity Index ◽  
Microbial Evolution ◽  
Water Flooding ◽  
Epifluorescence Microscopy ◽  
Production Well ◽  
Viral Abundance ◽  
Production Wells ◽  
Microbial Flooding

Viruses are widely distributed in various ecosystems and have important impacts on microbial evolution, community structure and function and nutrient cycling in the environment. Viral abundance, diversity and distribution are important for a better understanding of ecosystem functioning and have often been investigated in marine, soil, and other environments. Though microbes have proven useful in oil recovery under extreme conditions, little is known about virus community dynamics in such systems. In this study, injection water and production fluids were sampled in two blocks of the Daqing oilfield limited company where water flooding and microbial flooding were continuously used to improve oil recovery. Virus-like particles (VLPs) and bacteria in these samples were extracted and enumerated with epifluorescence microscopy, and viromes of these samples were also sequenced with Illumina Hiseq PE150. The results showed that a large number of viruses existed in the oil reservoir, and VLPs abundance of production wells was 3.9 ± 0.7 × 108 mL−1 and virus to bacteria ratio (VBR) was 6.6 ± 1.1 during water flooding. Compared with water flooding, the production wells of microbial flooding had relative lower VLPs abundance (3.3 ± 0.3 × 108 mL−1) but higher VBR (7.9 ± 2.2). Assembled viral contigs were mapped to an in-house virus reference data separate from the GenBank non-redundant nucleotide (NT) database, and the sequences annotated as virus accounted for 35.34 and 55.04% of total sequences in samples of water flooding and microbial flooding, respectively. In water flooding, 7 and 6 viral families were identified in the injection and production wells, respectively. In microbial flooding, 6 viral families were identified in the injection and production wells. The total number of identified viral species in the injection well was higher than that in the production wells for both water flooding and microbial flooding. The Shannon diversity index was higher in the production well of water flooding than in the production well of microbial flooding. These results show that viruses are very abundant and diverse in the oil reservoir’s ecosystem, and future efforts are needed to reveal the potential function of viral communities in this extreme environment.

scholarly journals Development Of Traditional Water Flooding To Increase Oil Recovery

2020 ◽  
Author(s):  
Sudad H Al-Obaidi ◽  
Khalaf FH
Keyword(s):  
Continuous Improvement ◽  
Oil Recovery ◽  
Technological Development ◽  
Geological Structure ◽  
Oil Fields ◽  
Water Flooding ◽  
Stage Of Development ◽  
Well Spacing ◽  
Production Wells ◽  
And Performance

The dynamics and performance of major oil deposits in late (final) stage of development of large oil fields are given the current rates of oil recovery. The high oil recoveries are resulted as a consequence of the favorable geological and physical characteristics of the development objects, application of development systems and optimal density well spacing, adequate geological structure, maintain during the process of the development the optimal rates of technological development, the modes of operation of wells and a project of the fund of production wells, continuous improvement of the project systems taking into account the dynamics of the reserves development and the clarification of the geological structure.

scholarly journals Simulation of Formation Damage after Long-Term Water Flooding

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Liu He ◽  
Gao Yang ◽  
Li Guoxin ◽  
Li Yiliang
Keyword(s):  
Oil Recovery ◽  
Element Model ◽  
Water Flooding ◽  
Permeability Change ◽  
Compression Pressure ◽  
Theoretical Understanding ◽  
Simulation Domain ◽  
Production Wells ◽  
Wellbore Failure

Water flooding is a commonly used technology for enhancing oil recovery. Its main mechanism is to maintain higher pressure to sweep oil towards production wells. However, the strong water flooding will cause higher compression pressure around the injection wellbore. This high pressure in the reservoir causes stress redistribution and higher stress near the wellbore which induces material damage and permeability change. We developed a fluid-solid coupling finite element model to simulate and quantitatively analyze the pressure evolution in the reservoir as well as damage and permeability change in the formation during long-term water flooding process. The obtained results offer theoretical understanding of the benefits (pore pressure increase in the simulation domain), rock damage, permeability change of long-term water flooding, and the insights of how to detect and prevent wellbore failure and collapse due to water flooding.

scholarly journals High Oil Recovery using Traditional Water-flooding under Compliance of the Planned Development Mode

2020 ◽  
Author(s):  
Sudad H Al-Obaidi
Keyword(s):  
Oil Recovery ◽  
Technological Development ◽  
Geological Structure ◽  
Oil Fields ◽  
Water Flooding ◽  
Development Mode ◽  
Stage Of Development ◽  
Well Spacing ◽  
Production Wells ◽  
And Performance

The dynamics and performance of major oil deposits in late (final) stage of development of large oil fields are given the current rates of oil recovery. The high oil recoveries are resulted as a consequence of the favorable geological and physical characteristics of the development objects, application of development systems and optimal density well spacing, adequate geological structure, maintain during the process of the development the optimal rates of technological development, the modes of operation of wells and a project of the fund of production wells, continuous improvement of the project systems taking into account the dynamics of the reserves development and the clarification of the geological structure.

scholarly journals Isolating, identifying and evaluating of oil degradation strains for the air-assisted microbial enhanced oil recovery process

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0243976
Author(s):  
Mingming Cheng ◽  
Long Yu ◽  
Jianbo Gao ◽  
Guanglun Lei ◽  
Zaiwang Zhang
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Enhanced Oil Recovery ◽  
Oxygen Concentration ◽  
Oil Recovery ◽  
Microbial Growth ◽  
Water Flooding ◽  
Oil Degradation ◽  
Microbial Enhanced Oil Recovery ◽  
Microbial Flooding

Due to the inefficient reproduction of microorganisms in oxygen-deprived environments of the reservoir, the applications of microbial enhanced oil recovery (MEOR) are restricted. To overcome this problem, a new type of air-assisted MEOR process was investigated. Three compounding oil degradation strains were screened using biochemical experiments. Their performances in bacterial suspensions with different amounts of dissolved oxygen were evaluated. Water flooding, microbial flooding and air-assisted microbial flooding core flow experiments were carried out. Carbon distribution curve of biodegraded oil with different oxygen concentration was determined by chromatographic analysis. The long-chain alkanes are degraded by microorganisms. A simulation model was established to take into account the change in oxygen concentration in the reservoir. The results showed that the optimal dissolved oxygen concentration for microbial growth was 4.5~5.5mg/L. The main oxygen consumption in the reservoir happened in the stationary and declining phases of the microbial growth systems. In order to reduce the oxygen concentration to a safe level, the minimum radius of oxygen consumption was found to be about 145m. These results demonstrate that the air-assisted MEOR process can overcome the shortcomings of traditional microbial flooding techniques. The findings of this study can help for better understanding of microbial enhanced oil recovery and improving the efficiency of microbial oil displacement.

scholarly journals Experimental Investigation on Injection and Production Pattern in Fractured-Vuggy Carbonate Reservoirs

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 603
Author(s):  
Juan He ◽  
Aowei Li ◽  
Shanshan Wu ◽  
Ruixue Tang ◽  
Dongliang Lv ◽  
...  
Keyword(s):  
Production Management ◽  
Flow Channel ◽  
Water Flooding ◽  
Production Well ◽  
New Production ◽  
Injection Wells ◽  
Gravity Segregation ◽  
Production Wells ◽  
Oil Water ◽  
Production Pattern

To constitute and adjust the injection and production pattern in fractured-vuggy reservoirs, we extracted twelve fractured-cave structures, fabricated them into physical models with acrylic plates, and performed experiments via these models. The results show that utilizing oil/water gravity segregation sufficiently and forming valid flow channels should be emphasized. Preferentially exploiting the reservoir body containing intermediate-scaled or large-scaled caves, arranging injection wells in fractures or small-scaled caves while placing production wells in large-scaled caves, and separately putting injection wells and production wells in low/high parts of an intermediate-scaled or large-scaled cave, were found to benefit oil/water gravity segregation and thus gain a better water flooding effect in these experiments. Experiments with combined models also figured out that, after adjusting the injection and production pattern, the valid flow channel newly formed must pass through caves containing enough residual oil to improve the water flooding effect and could be obtained by shutting down the old production well while adding a new production well, adding a new production well, or switching the production well into an injection well while adding a new production well. In the actual field, adjusting the well location and altering the flow channel were proposed to conduct together. This study may provide references on the production management of analogous reservoirs.

Laboratory Research on Enhancing Oil Recovery of Three Bacteria D1-3

2014 ◽  
Vol 884-885 ◽  
pp. 455-458
Author(s):  
Ming Ming Cheng ◽  
Guang Lun Lei ◽  
Jian Ying Liu ◽  
Jian Yang
Keyword(s):  
Oil Recovery ◽  
Chromatographic Analysis ◽  
Water Flooding ◽  
Laboratory Research ◽  
Degrading Bacteria ◽  
Remarkable Result ◽  
Core Flood ◽  
Microbial Flooding

A group of petroleum-degrading bacteria were obtained from the sludge samples that collected from the Triassic Yanchang 6 reservoir. Of these, three strains with maximum degradation performance were tested in this study. The chromatographic analysis showed that the content of molecules with 30 or more carbons of oil was reduced by 18.36%. Core flood experiments with different flooding rate showed that the oil recovery of microbial flooding was increased by 8.76% than water flooding. The research ruled out that the three strains have well compatibility with the reservoir with remarkable result of petroleum-degrading.

Preculaatities of evaluation of the effectiveness of flow deflection technologies

2018 ◽  
pp. 93-101
Author(s):  
A. A. Kazakov ◽  
V. V. Chelepov ◽  
R. G. Ramazanov
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Production Well ◽  
Oil Companies ◽  
Efficiency Calculation ◽  
Petroleum Companies ◽  
Flow Deflection ◽  
Recovery Methods

The features of evaluation of the effectiveness of flow deflection technologies of enhanced oil recovery methods. It is shown that the effect of zeroing component intensification of fluid withdrawal leads to an overestimation of the effect of flow deflection technology (PRP). Used in oil companies practice PRP efficiency calculation, which consists in calculating the effect on each production well responsive to subsequent summation effects, leads to the selective taking into account only the positive components of PRP effect. Negative constituents — not taken into account and it brings overestimate over to overstating of efficiency. On actual examples the groundless overstating and understating of efficiency is shown overestimate at calculations on applied in petroleum companies by a calculation.

scholarly journals Pore-Scale Simulation of Particle Flooding for Enhancing Oil Recovery

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2305
Author(s):  
Xiangbin Liu ◽  
Le Wang ◽  
Jun Wang ◽  
Junwei Su
Keyword(s):  
Oil Recovery ◽  
Flow Behavior ◽  
Ct Scanning ◽  
Water Flooding ◽  
Pore Scale ◽  
Simulation Techniques ◽  
Three Phase ◽  
Remaining Oil ◽  
Three Phase Flow ◽  
Displacement Force

The particles, water and oil three-phase flow behaviors at the pore scale is significant to clarify the dynamic mechanism in the particle flooding process. In this work, a newly developed direct numerical simulation techniques, i.e., VOF-FDM-DEM method is employed to perform the simulation of several different particle flooding processes after water flooding, which are carried out with a porous structure obtained by CT scanning of a real rock. The study on the distribution of remaining oil and the displacement process of viscoelastic particles shows that the capillary barrier near the location with the abrupt change of pore radius is the main reason for the formation of remaining oil. There is a dynamic threshold in the process of producing remaining oil. Only when the displacement force exceeds this threshold, the remaining oil can be produced. The flow behavior of particle–oil–water under three different flooding modes, i.e., continuous injection, alternate injection and slug injection, is studied. It is found that the particle size and the injection mode have an important influence on the fluid flow. On this basis, the flow behavior, pressure characteristics and recovery efficiency of the three injection modes are compared. It is found that by injecting two kinds of fluids with different resistance increasing ability into the pores, they can enter into different pore channels, resulting in the imbalance of the force on the remaining oil interface and formation of different resistance between the channels, which can realize the rapid recovery of the remaining oil.

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