Potential to enhance CO2 flooding in low permeability reservoirs by alcohol and surfactant as co-solvents

Ding, Mingchen; Wang, Yefei; Wang, Yefei; Zhao, Hailong; Liu, Dexin; Gao, Miao

doi:10.1016/j.petrol.2019.106305

Cited by 18 publications

(12 citation statements)

References 26 publications

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“…This conclusion seems to be similar to the CO 2 system; for example, Ding et. al reported that the tested surfactants with a shorter polyoxyethylene chain have better solubility in CO 2 and, consequently, a higher oil recover factor compared to longer polyoxyethylene chain surfactants. It is probable that the longer chain might self-coil and not fully stretch toward the crude oil; hence, the contact area between the chemical and oil is reduced.…”

Section: Results and Discussionmentioning

confidence: 99%

Effect of Functional Groups on Chemical-Assisted MMP Reduction of a Methane-Oil System

et al. 2021

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Natural gas injection (i.e., recycling) is a commonly used for enhanced oil recovery method and is potentially costeffective and efficient. However, natural gas injection, particularly methane, often has a high minimum miscibility pressure (MMP) which likely exceeds the fracture pressure of many otherwise viable reservoirs. Therefore, this work aims to investigate the potential of chemical-assisted MMP reduction of the methane-oil system to expand the application of miscible natural gas injection to more candidate reservoirs. In this context, we performed a study to test six potential surfactant-like chemicals with different polar headgroups (i.e., morpholine, aromatic sulfonic acid, aromatic carboxylic acid, and 2-oxypyrrolidine). The intent is to reduce the methane-oil interfacial tension using the vanishing interfacial tension method at a constant temperature of 373 K. First, at a concentration of 2 wt %, we tested the effect of the polar headgroups with the same hydrocarbon chain. Then, we investigated the effect of increasing the hydrocarbon chain length on the methane-oil miscibility. Our results show that chemical additives with the 2oxopyrrolidine and aromatic sulfonic acid functional groups give higher MMP reductions (8.7−9.6%, respectively) compared with aromatic carboxylic acid and morpholine groups, which only give limited or no MMP reduction. Moreover, the results show that the reduction in first contact miscibility pressure is higher (12.8−19.1%) compared to MMP. Furthermore, increasing the hydrocarbon chain length (from 10 to 13) of the 2-oxopyrrolidine and aromatic sulfonic acid molecules seems to decrease the efficiency in reducing MMP. Our results screen the potential of a combinatorial chemistry approach (where two molecules with differing sizes and functional groups can be readily joined together to make a large library of compounds) that can be used to identify chemical additives for reducing MMP of methane-oil. This approach underscores the importance of optimizing the functional group and hydrocarbon chain length in potential chemicals for MMP reduction. The outlined research results likely expand the application of miscible natural gas injection to deep and/or high-temperature reservoirs, in addition to the environmental benefits of reducing gas flaring and greenhouse gas emissions through natural-gas recycling.

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Section: Results and Discussionmentioning

confidence: 99%

Effect of Functional Groups on Chemical-Assisted MMP Reduction of a Methane-Oil System

et al. 2021

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“…The range of interfacial tension (between oil and CO 2 ) reduction is 8.55–25.51% by adding a chemical reagent according to Wu’s research . The slim tube displacement experiment shows that by injecting 0.003 PV isobutyl citrate or 0.1 PV QHB oil, the displacement efficiency increased by 13 and 10%, respectively. , In the core-flood experiment, the compound system of CO 2 /TX45/ethanol improves the oil recovery rate by 13.8% compared to the pure CO 2 system …”

Section: Introductionmentioning

confidence: 96%

“…22 In addition, the use of surfactants to change the properties of oil and gas in the process of CO 2 flooding has gradually become an important research direction. Existing research shows that isobutyl citrate (TIBC), 23 ethylene glycol butyl ether, mixed benzene, isopropyl citrate, span80, alkylphenol polyoxyethylene ether, 24,25 sodium huang succinate, 26−28 ME 1-6, 29 peracetyl glucose lauryl ester, 30 lauryl alcohol polyoxypropylene ether (C 12 PO 6 ), 31,32 TX45, 33 and cetyl acetyl octaester X 34 surfactants have excellent performance in promoting the miscibility of CO 2 and crude oil. Statistics show that the minimum miscible pressure range can be reduced by 7−24%.…”

Section: Introductionmentioning

confidence: 99%

“…23,25 In the core-flood experiment, the compound system of CO 2 /TX45/ethanol improves the oil recovery rate by 13.8% compared to the pure CO 2 system. 33 The selection of chemical reagents to improve the degree of CO 2 and crude oil miscibility is the current research frontier, but there is no systematic theoretical basis and evaluation method for the selection of reagents, and the relevant mechanism of action still needs to be explained. Therefore, in this paper, first based on the molecular structure theory combined with the solubility test experiment, the surfactants with good CO 2 -philic properties are selected.…”

Section: Introductionmentioning

confidence: 99%

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Study on Oil and Gas Amphiphilic Surfactants Promoting the Miscibility of CO₂ and Crude Oil

et al. 2021

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In order to cope with the global climate crisis, carbon capture, utilization, and storage are the key technologies to achieve carbon neutrality, and it is an elegant geological utilization method for the oil and gas industry to improve the recovery rate of crude oil by using CO2. However, in practical applications, the problem of low miscibility of CO2 and crude oil, resulting in low oil displacement efficiency, cannot be avoided. Thus, finding an appropriate method to increase the utilization rate of CO2 is a worth in-depth study. In light of this, this paper carries out the study on improving the CO2 flooding efficiency by using oil and gas amphiphilic surfactants. First of all, according to the molecular structure theory and the solubility experiment of surfactants in CO2, five kinds of surfactants and two kinds of additives with good performance of oil and gas were selected. Then, three experiments were conducted to explore the mechanism of the selected surfactants. The main mechanism of promoting the miscibility of CO2–crude oil is to reduce the interfacial tension of the oil and gas phases, followed by increasing the volume expansion of crude oil and reducing the viscosity of crude oil. Finally, through the slim tube displacement experiment, the oil displacement efficiency effect of adding the compound systems of SPO5/n-pentanol was simulated. The results show that the oil displacement efficiency is significantly higher than that of pure CO2 flooding, and the pressure of miscibility reduces at the same time. The selected reagents have a good effect of promoting miscibility. Therefore, this is an effective method to improve the geological utilization of CO2.

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“…Cosolvents are used to adjust the properties of CO 2 in the area of organic matter and crude oil extraction. , Rudyk et al investigated the extraction of oil sand, bitumen, and crude oil by CO 2 with alcohols as cosolvents under conditions of 20–60 MPa and 60–110 °C. − Ethanol had a great effect to improve the recovery yield and to extract heavier fractions faster than methanol. Bermejo et al investigated the effects of ethyl lactate, ethyl acetate, and ethanol on the scCO 2 extraction of caffeine from green tea.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Shale Oil Recovery by the Huff and Puff Method Using CO₂ and Cosolvent Mixed Fluids

et al. 2019

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Shale oil, as one of the unconventional resources, has become increasingly important to supplement conventional oil and gas. Although CO 2 has great potential to enhance shale oil recovery by the huff and puff method, the experimental results show that the enhanced values of shale oil recovery are unstable and have great fluctuations for different cores. In order to increase the stability of CO 2 huff and puff and further enhance oil recovery, cosolvents such as ethanol, isopropanol, ethyl acetate, and acetone were chosen to construct CO 2 /cosolvent mixed fluids and the experiments of huff and puff by the mixed fluids were carried out. The results show that CO 2 /cosolvents can enhance the shale oil recoveries of the matrix and fracture. CO 2 /ethanol has the highest oil recovery among the mixed fluids. In particular, for cycles 2 and 3 in the huff and puff process, CO 2 /ethanol has a much larger oil recovery than CO 2 . Moreover, the effects of ethanol concentration in the mixed fluids on the enhanced shale oil recovery were investigated. The enhanced oil recoveries by CO 2 /ethanol mixed fluids increase with the increase of ethanol concentration. Furthermore, the mechanisms to enhance shale oil recovery by CO 2 /cosolvent fluids were discussed by measurements of the pressure decay process and interfacial tension. The presence of ethanol can not only accelerate the transfer of CO 2 to the oil phase in the porous media during the huff process, to make more CO 2 transfer into the oil phase, but also decrease the interfacial tension between oil and CO 2 as well as the minimum miscibility pressure, to make oil and CO 2 mixed fluids have a longer time to flow out in one phase than CO 2 in the puff process. Therefore, the CO 2 /cosolvent mixed fluids, especially CO 2 /ethanol, can be used to further enhance shale oil recovery during the huff and puff process.

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Potential to enhance CO2 flooding in low permeability reservoirs by alcohol and surfactant as co-solvents

Cited by 18 publications

References 26 publications

Effect of Functional Groups on Chemical-Assisted MMP Reduction of a Methane-Oil System

Effect of Functional Groups on Chemical-Assisted MMP Reduction of a Methane-Oil System

Study on Oil and Gas Amphiphilic Surfactants Promoting the Miscibility of CO₂ and Crude Oil

Enhanced Shale Oil Recovery by the Huff and Puff Method Using CO₂ and Cosolvent Mixed Fluids

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Potential to enhance CO2 flooding in low permeability reservoirs by alcohol and surfactant as co-solvents

Cited by 18 publications

References 26 publications

Effect of Functional Groups on Chemical-Assisted MMP Reduction of a Methane-Oil System

Effect of Functional Groups on Chemical-Assisted MMP Reduction of a Methane-Oil System

Study on Oil and Gas Amphiphilic Surfactants Promoting the Miscibility of CO2 and Crude Oil

Enhanced Shale Oil Recovery by the Huff and Puff Method Using CO2 and Cosolvent Mixed Fluids

Contact Info

Product

Resources

About

Study on Oil and Gas Amphiphilic Surfactants Promoting the Miscibility of CO₂ and Crude Oil

Enhanced Shale Oil Recovery by the Huff and Puff Method Using CO₂ and Cosolvent Mixed Fluids