Effect of gas contamination and well depth on pressure interval of CO2 near-miscible flooding

Chen, Hao; Li, Bowen; Zhang, Xiansong; Wang, Quan; Wang, Xiaoqiang; Yang, Shenglai

doi:10.1016/j.petrol.2019.01.062

Cited by 28 publications

(7 citation statements)

References 24 publications

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“…This is because most of the contaminated gases are methane (CH 4 ), which is very difficult to miscible with oil. Besides, the ratio of volatile components (CH 4 + N 2 ) is over 90%, while that of the intermediate components (C 2 –C 6 ) is less than 10%, and the overall effect is not beneficial for achieving miscibility . In addition, it can be found that the pressure interval expands with an increase in the contaminated gases in the injection gas.…”

Section: Resultsmentioning

confidence: 97%

“…Besides, the ratio of volatile components (CH 4 + N 2 ) is over 90%, while that of the intermediate components (C 2 −C 6 ) is less than 10%, and the overall effect is not beneficial for achieving miscibility. 36 In addition, it can be found that the pressure interval expands with an increase in the contaminated gases in the injection gas. For each 10% decrease in CO 2 content, MNMP and MMP increase, respectively.…”

Section: Determination Of Purity Lower Limit Of Immiscible Co 2 Flood...mentioning

confidence: 99%

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Study on Different Miscibility Intervals of an Impure CO₂-Crude Oil System in Offshore Low-Permeability Reservoirs

Yang,

Zhang,

Tan

et al. 2024

Energy Fuels

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CO2-enhanced oil recovery (EOR) technology considers the two themes of energy resource development and environmental protection. However, the effect of CO2 purity on the range of different miscible degrees of the CO2-crude oil system and the development characteristics of CO2 flooding in offshore low-permeability reservoirs. Therefore, based on the fluid samples collected from different target wells, the quantitive method of dividing the pressure range of three kinds of miscible degrees under different CO2 purities through the slim tube experiment and numerical simulation was established. In addition, the effect of the CO2 purity and the pressure ranges of near-miscible and miscible flooding in the different target wells under various development stages were also evaluated, and the lower limit of pure/impure CO2 for miscible flooding and near-miscible flooding in each well was also calculated. The results showed that the traditional slim tube experiment leads to a fluctuation pressure range, which results in errors. Besides, the near-miscibility pressure range of the pure CO2-oil system in the BZ25–1 reservoir is 27.1–31.4 MPa, and compared with the pure CO2-crude oil system, the minimum miscibility pressure (MMP) of 80% pure CO2-crude oil system and 24% pure CO2-crude oil system increased by 7.98 and 40.59%, respectively. Additionally, the CO2 purity range of near-miscible flooding is 61–100% under the condition of the BZ25–1 reservoir. The results have guiding significance for deepening the implementation of the CO2-EOR technology in offshore low-permeability reservoirs.

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Section: Resultsmentioning

confidence: 97%

Section: Determination Of Purity Lower Limit Of Immiscible Co 2 Flood...mentioning

confidence: 99%

Study on Different Miscibility Intervals of an Impure CO₂-Crude Oil System in Offshore Low-Permeability Reservoirs

Yang,

Zhang,

Tan

et al. 2024

Energy Fuels

Self Cite

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“…Although some basic understanding has been achieved, there are still many problems that have not been solved. Chen H et al (2020) prospected the key issues of CO 2 near-miscible flooding. Chai et al (2022) studied the molecular diffusion law and simulation of CO 2 in the water-crude oil system.…”

Section: Mechanism Of Co 2 Flooding and Storagementioning

confidence: 99%

Key Problems and Countermeasures in CO₂ Flooding and Storage

CHEN

2023

Acta Geologica Sinica (Eng)

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Based on literature research in combination with the practice of CO2 flooding and storage in Jilin Oilfield, this study assesses the key problems in CO2 flooding and storage, proposing the corresponding countermeasures from five aspects of CO2 gas source condition, namely geological condition evaluation, scheme design incoordination with other production methods, economic and effectiveness evaluation, together with dynamic monitoring and safety evaluation. The results show that CO2 flooding is the most economic and effective CO2 storage method. In eastern China, inorganic origin CO2 gas reservoirs are widely developed and are especially the most enriched in the Paleozoic carbonate rock strata and the Cenozoic Paleogene–Neogene system, which provide a rich resource base for CO2 flooding and storage. In the future, CO2 generated in the industrial field will become the main gas source of CO2 flooding and storage. The evaluation of geological conditions of oil and gas reservoirs is the basis for the potential evaluation, planning scheme design and implementation of CO2 flooding and storage. CO2 storage should be below the depth of 800 m, the CO2 flooding and storage effects in low‐permeability oil reservoirs being the best. CO2 geological storage mechanisms primarily consist of tectonic geological storage, bound gas storage, dissolution storage, mineralization storage, hydrodynamic storage and coalbed adsorption storage. The practice of CO2 flooding and storage in Jilin Oilfield demonstratesthat the oil increment by CO2 flooding is at least 24% higher than by conventional water flooding. The most critical factor determining the success or failure of CO2 flooding and storage is economic effectiveness, which needs to be explored from two aspects: the method and technology innovation along with the carbon peaking and carbon neutrality policy support. After CO2 is injected into the reservoir, it will react with the reservoir and fluid, the problem of CO2 recovery or overflow will occur, so the dynamic monitoring and safety evaluation of CO2 flooding and storage are very important. This study is of great significance to the expansion of the application scope of CO2 flooding and storage and future scientific planning and deployment.

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“…In comparison to other hydrocarbon gas injections, the oil recovery values are much better in the CO2 miscible method [10]. Hao et al [11] inferred that under certain conditions, CO2 and crude oil can be miscible, thereby reducing the viscosity of the formation fluids and enhancing their flow capacity. The oil displacement efficiency of CO2 miscible flooding is affected by many factors.…”

Section: Introductionmentioning

confidence: 99%

Research on the Effect of Carbon Dioxide Miscible Fracturing Huff and Puff in Enhancing Oil Recovery

Xu,

Wang,

Gao

et al. 2024

Preprint

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Carbon dioxide (CO2)miscible fracturing huff and puff technology plays a pivotal role in enhancing the recovery rate of crude oil, particularly in reservoirs with challenging physical properties, strong water sensitivity, high injection pressure, and complex water injection dynamics. In this study, the oil-increasing mechanism and huff and puff effect of CO2 miscible fracturing fluid are investigated through a comprehensive experimental approach. Specifically, experiments on PVT gas injection expansion, minimum miscible pressure, and CO2 miscible fracturing huff and puff are conducted on the G fault block reservoir in J Oilfield. The findings demonstrate that injecting CO2 into reservoirs leads to oil volume expansion, viscosity reduction, and saturation pressure increase. Additionally, the inclusion of solubilizers and viscosity reducers further enhances the efficiency of crude oil extraction. Solubilizers not only improve oil recovery but also reduce the minimum miscible pressure required for effective CO2 dispersion. Furthermore, the shut-in time, permeability, and huff and puff method all have considerable impacts on huff and puff recovery rate. This study offers valuable technical insights, supporting the application of CO2 miscible fracturing huff and puff technology to enhance oil recovery in low-permeability reservoirs.

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Effect of gas contamination and well depth on pressure interval of CO2 near-miscible flooding

Cited by 28 publications

References 24 publications

Study on Different Miscibility Intervals of an Impure CO₂-Crude Oil System in Offshore Low-Permeability Reservoirs

Study on Different Miscibility Intervals of an Impure CO₂-Crude Oil System in Offshore Low-Permeability Reservoirs

Key Problems and Countermeasures in CO₂ Flooding and Storage

Research on the Effect of Carbon Dioxide Miscible Fracturing Huff and Puff in Enhancing Oil Recovery

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Effect of gas contamination and well depth on pressure interval of CO2 near-miscible flooding

Cited by 28 publications

References 24 publications

Study on Different Miscibility Intervals of an Impure CO2-Crude Oil System in Offshore Low-Permeability Reservoirs

Study on Different Miscibility Intervals of an Impure CO2-Crude Oil System in Offshore Low-Permeability Reservoirs

Key Problems and Countermeasures in CO2 Flooding and Storage

Research on the Effect of Carbon Dioxide Miscible Fracturing Huff and Puff in Enhancing Oil Recovery

Contact Info

Product

Resources

About

Study on Different Miscibility Intervals of an Impure CO₂-Crude Oil System in Offshore Low-Permeability Reservoirs

Study on Different Miscibility Intervals of an Impure CO₂-Crude Oil System in Offshore Low-Permeability Reservoirs

Key Problems and Countermeasures in CO₂ Flooding and Storage