PETROLEUM SCIENCE AND TECHNOLOGY
·
2022
·
IF 1.695
Kaixiang Cui,Yufei Xia,Linlin Tian,Shuai Wang,Yongyao He
In order to enhance oil recovery, supercritical CO2 (scCO2) flooding has been applied in many oilfields to extract oil and gas post primary recovery. However, it causes serious scaling problems in the reservoir, oil well and production tubing. In this article, the produced water quality before and after scCO2 flooding in carbonate reservoirs are analyzed. The scaling trend of produced water before and after scCO2 flooding was calculated by using the Davis-stiff saturation index and Ryznar stability index methods. Static experiments and scanning electron microscope (SEM) are used to study the scale inhibition performance and mechanism of HEDP, ATMP, MA-AA, and PAA on CaCO3 in produced water before and after scCO2 flooding. The results show that after scCO2 flooding, the quality of produced water changes obviously, thus the scaling trend of produced water increases, the growth of CaCO3 crystal is affected and the scale inhibition efficiency of conventional scale inhibitors decreases.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Teng Lu,Zhaomin Li,Weiyu Fan,Xinglu Zhang,Qichao Lv
The deposition of asphaltenes in porous media is one of the most difficult problems during CO2 flooding. In this paper, the adsorption of asphaltenes onto Al2O3 nanoparticles was studied through two methods: (i) by adding a certain mass of nanoparticles in a fixed volume of solution with different initial concentrations of asphaltenes and (ii) by exposing a certain amount of asphaltenes in a fixed volume of solution to different nanoparticles additions. Then, the impact of Al2O3 nanoparticles on the asphaltene precipitation was investigated using the IFT behavior of the oil–CO2 system. Coreflood tests were conducted to study the potential of nanoparticles for inhibition of asphaltenes damage during CO2 flooding, and the effect of injection parameters of nanofluid. It is found that the solid–liquid equilibrium (SLE) can well describe the isotherms of asphaltene adsorption. The trend of the IFT–pressure curve is affected by asphaltene accumulation at the oil–CO2 interface. The slopes in the high pressure region can be used to examine the intensity of asphaltene precipitation. As the addition of nanoparticles increases, the IFT slope in the high pressure range decreases. This is because the asphaltenes are absorbed at the surface of nanoparticles. As a result, the nanoparticles prevent asphaltene precipitation from accumulating at the CO2–oil interface, hence causing asphaltene to remain within the bulk of oil. The higher the mass fraction of Al2O3 nanoparticles is, the lower the intensity of the asphaltene precipitation would be. The coreflood results show that the injection of Al2O3 nanofluid can lessen the oil permeability reduction because the nanoparticles can inhibit the deposition of asphaltenes onto the sand surfaces in the porous media. The 0.5 wt % nanoparticles and the 0.1 nanofluid/CO2 slug volume ratio are considered as the optimum for inhibiting asphaltenes damage during CO2 flooding. Continuous CO2 and nanofluid injection could be more effective compared with the cyclic injection pattern.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2025
·
IF 4.3
Shuaishuai Zhao,Li Liu,Zhihao Li,Xuliang Fan,Zhiqiang Wang,Mengyi Xing,Fushan Li
CO2 flooding is one of the paramount approaches to ameliorating the oil recovery rate of low-permeability reservoirs. Additionally, the physical and geological characteristics of low-permeability reservoir crude oil are less desirable owing to the influence of continental sedimentary structures. The minimum miscibility pressure (MMP) between CO2 and crude oil is generally higher than the formation fracture pressure, thereby rendering it difficult for CO2 to form miscibility with crude oil. Under such circumstances, a miscibility-reducing agent can be adopted to lower the miscibility pressure between CO2 and crude oil, thus achieving CO2 oil miscible phase flooding and elevating recovery efficiency. This paper first selected the most effective miscibility-reducing agent through molecular simulation experiments and core displacement experiments, and subsequently evaluated the injection effect of the miscibility-reducing agent on heightening the recovery rate of CO2 flooding in low-permeability reservoir cores. This research obtained the effect of the miscibility-reducing agents on the aggregation degree of CO2 molecules and asphaltene molecules during the oil gas mixing process from the radial distribution function and analyzed its function mechanism. On this basis, the core flooding experiment method was adopted to screen for the optimal miscibility-reducing agent with the best miscibility-reducing agent effect. Afterward, the impact of miscibility-reducing agent injection on the CO2 flooding development effect of the low-permeability core was evaluated systematically. As demonstrated by the molecular simulation results, selected miscibility-reducing agents displayed desirable electron transfer ability with CO2; Triisobutyl citrate can effectively heighten the aggregation degree of CO2 molecules and lessen the aggregation degree of asphaltene molecules, with the most conspicuous effect; The results of the core flooding experiment revealed that upon the injection of triisobutyl citrate, the MMP reduction between CO2 and crude oil exhibited the most remarkable trend, so it was selected as the best miscibility-reducing agent. The mechanism by which triisobutyl citrate can effectively reduce MMP mainly includes lowering crude oil viscosity and oil gas interfacial tension, and promoting the CO2 extraction ability. The indoor three-dimensional well network model CO2 flooding experiment results suggested that after injecting 0.07 PV of triisobutyl citrate preflush slug, the CO2 flooding recovery rate increased from 47.78% OOIP without the injection of miscibility-reducing agents to 59.86% OOIP. The selected triisobutyl citrate displayed a striking effect on augmenting the CO2 flooding recovery rate of low-permeability reservoirs. The research results provide a reference and inspiration for the high-quality and efficient development of CO2 flooding in low-permeability oil reservoirs.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Qi Gao,Bo Wang,Japan Trivedi,Xingguang Xu,Shuai Liu
CO2-responsive foam (CRF) is a highly promising candidate for CO2-enhanced oil recovery (CO2-EOR) because it displays higher stability than the surfactant-stabilized foam owing to the formation of robust wormlike micelles (WLMs) upon exposure to CO2. In this work, the nanoparticle-enhanced CO2-responsive foam (NECRF) was properly prepared using lauryl ether sulfate sodium (LES)/diethylenetriamine/nano-SiO2, and its interfacial properties and EOR potential were experimentally and numerically assessed, aiming to explore the feasibility and effectiveness of NECRF as a novel CO2-EOR technique. It was found that the interfacial expansion elastic modulus increased 6-fold after CO2 stimulation. The modulus continued to increase with the introduction of nano-SiO2 owing to the pronounced synergistic effect of WLMs and nanoparticles. In addition to increasing the viscosity of the foaming liquid, WLMs and nano-SiO2 enhanced the shearing resistance of the NECRF as well. Calculations demonstrated that both the coarsening rate and the size distribution uniformity coefficient of NECRF were markedly lower than that of the LES foam, which subsequently inhibited NECRF decay and greatly improved its dynamic stability. Besides, molecular dynamics simulation revealed that adding inorganic salts to NECRF could notably enhance the foaming performance due to the intensified hydration of surfactant head groups and reduced binding energy of neighboring molecules. Nuclear magnetic resonance-assisted core flooding experiments validated the exceptional capacity of NECRF to sweep the low-permeability region and improve the conformance profile. Overall, these findings may provide valuable insights into the development and application of novel materials and strategies for the CO2-EOR.
研究领域:
石油工程
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 19
·3886
·
IF 5
Xin Chen,Yiqiang Li,Xiaoguang Sun,Zheyu Liu,Jianbin Liu,Shun Liu
CO2flooding is a favorable technical means for the efficient development of low-permeability reservoirs, and it can also contribute to the realization of net-zero CO2emissions. However, due to the unfavorable viscosity ratio and gravity overriding effect, CO2channeling will inevitably occur, seriously affecting its storage and displacement effects. This paper conducts a systematic study on the application of polymer-assisted CO2flooding in low-permeability reservoirs. Firstly, the polymer agent suitable for low-permeability reservoirs is optimized through the viscosity-increasing, rheological, and temperature- and salt-resistant properties of the solution. Then, the injectivity performance, resistance-increasing ability, and profile-improving effect of the polymer solution were evaluated through core experiments, and the optimum concentration was optimized. Finally, the enhanced oil recovery (EOR) effects of polymer-assisted and water-assisted CO2flooding were compared. The results show that the temperature-resistant polymer surfactant (TRPS) has a certain viscosity-increasing performance, good temperature resistance performance, and can react with CO2to increase the solution viscosity significantly. Meanwhile, TRPS has good injection performance and resistance-increasing effect. The resistance increasing factor (ηandη′) of TRPS-assisted CO2flooding increases with increased permeability, the concentration of TRPS solution, and injection rounds. Consideringη′ and the profile improvement effect comprehensively, the application concentration of TRPS should be 1000 mg/L. The EOR effect of TRPS-assisted CO2flooding is 8.21% higher than that of water-assisted CO2flooding. The main effective period is in the first and second rounds, and the best injection round is three. The research content of this paper can provide data support for the field application of polymer-assisted CO2flooding in low-permeability reservoirs.
研究领域:
石油工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Xu Li,Liming Zheng,Guanghui Li,Jingyang Pu,Tong Zhang,Feifei Huang
CO 2 -enhanced oil recovery (CO 2 -EOR) has attracted great attention due to its dual effects of geological carbon storage and economic benefits, but the clay swelling, asphaltene deposition and gas channeling induced by CO 2 still restrict its field application. The employment of chemical agents for the purpose of improving CO 2 -EOR performance is often limited by the heterogeneity of reservoirs and the potential for formation damage. Physical methods, such as ultrasonic-assisted CO 2 flooding, appear to offer a promising alternative for CO 2 -EOR and geological sequestration. This study has conducted oil displacement experiments to investigate the EOR potential of ultrasonic-assisted CO 2 flooding in tight reservoirs and clarify the effects of different ultrasound parameters. The ultrasonic waves with 20 kHz of acoustic frequency, 30 W/cm 2 of sound intensity, 30 min of sonication time and moderate intermittent working mode can yield violent cavitation effects and avoid undesirable energy dissipation. Nearly a quarter of the saturated crude oil can be recovered from the tight core through ultrasonic-assisted CO 2 flooding. It can be attributed to the composition alterations of crude oil and property changes of core matrix. Coupling with ultrasonic waves, CO 2 would extract and vaporize crude oil more easily, which promotes oil swelling, lowers oil density and viscosity, decreases oil–gas interfacial tension and thus improves oil recovery. Besides, the ultrasound can help to mitigate the impact of CO 2 adsorption-induced clay swelling on pore sizes through fluctuating pressure. And the strong hydrodynamic shear forces generated by mechanical vibration of ultrasound may also help to connect individual small pores and extend micro-fractures. These synergistic effects result in the transformation of micropores into mesopores and macropores. Furthermore, the wettability alteration of core samples implies that the ultrasonic-assisted CO 2 flooding can induce the detachment of oil films from the rock surface. Finally, the results of molecular dynamics simulations indicate that the improvement in pressure inside the core sample resulting from ultrasonic cavitation facilitates the mixing of CO 2 and oil, thereby weakening gas channeling and improving the displacement efficiency.
研究领域:
石油工程
·
地质学
·
物理化学
✓ 已验证
DOI
高影响因子
Processes
·
2025
·Vol. 13
·期 9
·2903
·
IF 2.8
Ping Guo,Yong Li,Yanbao Liu,Yunlong Zou
In this study, a new type of double crosslinked nanospheres (DCNPM-A) was developed to solve the problem of gas channeling caused by fracture development in the process of CO2oil displacement, and the microsphere system with delayed swelling was successfully synthesized by inverse micro lotion polymerization. The microsphere adopts a dual crosslinking structure of stable crosslinking agent (MBA) and unstable crosslinking agent (UCA), achieving intelligent sealing function of shallow low expansion and deep high temperature triggered secondary expansion. The successful preparation of microspheres was verified by characterization methods such as Zeta potential and SEM, and the effects of reaction temperature, time, initiator and crosslinking agent dosage on microsphere properties were systematically studied. The experimental results show that DCNPM-A microspheres exhibit excellent expansion performance, thermal stability, and acid resistance in acidic, high-temperature, and high mineralization environments. Their expansion ratio can reach 13.5 times, and they can maintain stability for more than 60 days in supercritical CO2environments. Core displacement experiments have confirmed that the microspheres have the best sealing performance in matrices with a permeability of 10 × 10−3μm2and fractures with a width of 0.03 mm. The combination of 0.8 PV injection volume, 0.5 mL·min−1injection rate, and continuous injection method significantly improved the plugging rate and recovery rate of CO2flooding. This study provides new technical support for the efficient development of low-permeability fractured reservoirs.
研究领域:
石油工程
·
提高采收率
·
高分子材料科学
·
油藏工程
✓ 已验证
DOI
高影响因子
Energies
·
2024
·Vol. 17
·期 11
·2758
·
IF 3
Qi Liu,Yangwen Zhu,Hang Ye,Haiying Liao,Quanqi Dai,Michelle Tiong,Chenggang Xian,Dan Luo
Carbon capture, utilization, and storage (CCUS) technology has emerged as a pivotal measure in mitigating global climate change. Notably, CO2-EOR is esteemed for its dual function of sequestering CO2and enhancing oil recovery. However, this process presents challenges related to asphaltene deposition during CO2flooding, leading to reservoir damage, such as pore plugging. This study systematically manipulated the factors inducing CO2-induced asphaltene deposition, elucidating the mechanisms and magnitudes of asphaltene precipitation. Additionally, the study investigated the efficacy of carbon quantum dots (CQDs) in mitigating asphaltene deposition. Experimental findings indicated a positive correlation between asphaltene deposition and level of asphaltene content, CO2injection ratio, and temperature. Moreover, with an increase in experimental pressure, the asphaltene deposition rate demonstrated an initial increase followed by a subsequent decline. Leveraging their favorable compatibility with asphaltene, CQDs effectively suppressed the aggregation behavior of asphaltene. In the presence of CQDs, the onset of asphaltene precipitation was delayed from 45 V% to 55 V%, with the highest inhibition rate reaching approximately 36% at an optimal CQD concentration of 20 mg/L. This study proposes a novel approach to address asphaltene deposition issues in CO2-EOR processes, contributing to the enhancement of recovery rates in low-permeability reservoirs.
研究领域:
石油工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Hao Shen,Zihao Yang,Xiaochen Li,Ying Peng,Meiqin Lin,Juan Zhang,Zhaoxia Dong
Hydraulic fracturing and CO 2 flooding are extensively used in low-permeability reservoirs to enhance oil recovery (EOR). However, due to the serious heterogeneity of the formation, CO 2 is prone to break through the oil-bearing zone prematurely, which leads to the decrease of the swept volume. Conventional blocking agents have some defects such as difficult injection, poor stability and weak sealing strength. Therefore, it is critical to developing a new type of channeling blocking agent for low-permeability fractured reservoirs. In this study, ten kinds of chemicals with tertiary amino groups are filtered for the most effective CO 2 -responsive agent, which turns out to be N, N-Dimethyl erucamide tertiary amine (DMETA). Subsequently, rheological properties, response performance, and microstructure of the optimum agent are researched systematically through rheological experiments, CO 2 -response processes and Cryo-TEM. The results show that the viscosity of the DMETA solution can increase to nearly 605,700 mPa·s by self-assembly into wormlike micelles (WLMs). And it can be reversibly circulated between low viscosity and high viscosity by alternately introducing and removing CO 2 , which endows it with the ability to healing its viscoelasticity under an environment full of CO 2 . A new method based on optical microrheology is proposed to study the viscoelastic properties of WLMs under no external force. The experiments prove that the network structure is not stable after formation, but remains in a continuous process of separation and reconstruction as “a living polymer.” Furthermore, the plugging performance and EOR capacity are evaluated using fractured tight cores. The experiments demonstrate that the optimum agent can effectively restrain gas channeling and enhance recovery factor by 21.7%. We expect our work can provide insights for the synthesis of CO 2 -responsive WLMs and guidance for retarding gas channeling during CO 2 flooding in low permeability reservoirs.
研究领域:
石油工程
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
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