Dynamic characteristics and influencing factors of CO2 huff and puff in tight oil reservoirs

Xiang, Tao; Li, Yiqiang; Han, Xue; Zhou, Yongbing; Zhan, Jianfei; Xu, Miaomiao; Zhou, Rui; Cui, Kai; Chen, Xiaolong; Wang, Lei

doi:10.1016/s1876-3804(21)60079-4

Cited by 27 publications

(11 citation statements)

References 19 publications

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“…Compared with conventional single well CO2 huff and puff experiment [9,10,11] , because of the lack of CO2 flowback stage, the production process is more similar to the CO2 injection flooding process. Compared with CO2 injection flooding, the CO2 diffusion degree is higher in the soaking stage of asynchronous injection and production in different Wells, which promotes the miscibility degree between CO2 and crude oil.…”

Section: Eor Mechanismmentioning

confidence: 99%

Exploration Experiment of Development Method After Depletion of Tight Oil

Hao¹,

Chen²,

Yu³

et al. 2023

Preprint

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Section: Eor Mechanismmentioning

confidence: 99%

Exploration Experiment of Development Method After Depletion of Tight Oil

Hao¹,

Chen²,

Yu³

et al. 2023

Preprint

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“…However, due to the characteristics of the poor physical properties, small pore throat, and serious heterogeneity of tight reservoirs, problems such as high water injection pressure and poor oil recovery can easily be caused in the development process . As the main technology of tertiary oil recovery, CO 2 flooding has significant advantages in tight oil reservoir development due to its better injection capacity and dissolution characteristics − and has been widely used in oil field practice. − At the same time, as one of the main ways to achieve carbon neutrality, CO 2 flooding is also conducive to achieving the double benefits of enhanced oil recovery and carbon emission reduction. − Therefore, it is necessary to further clarify the miscibility mechanism of CO 2 and oil in tight sandstone reservoirs.…”

Section: Introductionmentioning

confidence: 99%

Miscibility Characteristics of CO₂–Oil in Tight Sandstone Reservoirs: Insights from Molecular Dynamics Simulations

Liu,

Wang,

Yang

et al. 2024

ACS Omega

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Identifying the microscopic mechanism of CO 2 −oil miscibility is significant for the CO 2 enhanced oil recovery (CO 2 − EOR) in tight sandstone reservoirs. In this work, the effects of oil composition, formation pressure, temperature, and methane content on the characteristics of the CO 2 −oil miscibility were systematically studied by molecular simulation methods. According to the change of oil−gas centroid displacement, the CO 2 −oil miscibility behavior was divided into four stages: rapid diffusion, CO 2 dissolution and oil swelling, competitive adsorption and oil film detachment, and complete miscibility or dynamic equilibrium stability. The results showed that light or medium component oil is more easily miscible with CO 2 under reservoir conditions. The changes in temperature and pressure will greatly influence the oil−gas miscibility. Increasing the temperature is conducive to reducing the adsorption energy between oil and quartz, thus improving the miscibility of CO 2 and heavy component oil. However, the static swelling effects of CO 2 alone cannot effectively displace the heavy component oil on quartz. The CO 2 diffusion coefficient perpendicular to the quartz surface does not increase continuously with the temperature increase due to the adsorption of oil and quartz. There is a critical temperature range of 320−340 K, which makes the miscibility effects the best. A small amount of CH 4 can enhance the interaction energy between the two phases of oil and gas, thus promoting the miscibility of CO 2 and oil at the interface. However, it is not conducive to oil film detachment, with the CH 4 content increasing.

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“…Considerable research has been conducted on CO 2 huff-n-puff in tight sandstone reservoirs. Previous studies have explored the effects of injection volume, injection pressure, and huff-n-puff cycles on recovery efficiency. − Ding et al considered the influence of four factors on CO 2 huff and puff times, matrix permeability, matrix size, and gas type and concluded that matrix permeability has a stronger influence on CO 2 huff and puff recovery than matrix size. Huang et al established a microreservoir classification standard based on field emission scanning electron microscopy (FE-SEM), CST, nanocomputed tomography (Nano-CT), HPMI, NMR, and other experimental methods, evaluating the influence of asphaltene content on pore structure and recovery efficiency.…”

Section: Introductionmentioning

confidence: 99%

Microscopic Production Characteristics of Huff-n-Puff after CO₂ Flooding in Tight Oil Sandstone Reservoirs

Xue,

Gao,

Wen

et al. 2023

Energy Fuels

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This study aims to investigate the impact of CO2 huff-n-puff after CO2 flooding on recovery efficiency in tight sandstone reservoirs. The experimental methodology involved the selection of three representative cores with different permeability levels to emulate class I, II, and III reservoirs. To examine immiscible, nearly miscible, and miscible conditions for different reservoir samples, a physical simulation flow system integrated with nuclear magnetic resonance technology was employed. CO2 flooding was performed followed by CO2 huff-n-puff experiments at five pressures, enabling a quantitative analysis of oil production characteristics in various pores during the flooding and huff-n-puff processes. This study provides insights into the microscopic production characteristics and oil recovery influenced by huff-n-puff in tight sandstone reservoirs subsequent to CO2 flooding. The experimental results highlight that recovery efficiency increases with higher permeability, with class I reservoir samples exhibiting the highest recovery rate at 76.47%, followed by class II reservoirs at 69.33%, and class III reservoirs at 44.43%. Huff-n-puff recovery for class I and class II reservoirs gradually declines with increasing pressure after flooding, whereas class III reservoirs display an opposite trend, with recovery gradually increasing. In addition, the microscopic oil distribution characteristics change after flooding. During the near-miscible phase, class I and class III reservoirs predominantly yield oil from medium and small pores, while class II reservoirs primarily produce oil from medium pores. Upon reaching miscibility, oil production in class I, II, and III reservoirs primarily occurs in small pores, with some contribution from medium pores. The research findings presented in this paper provide valuable theoretical support for future CO2 flooding operations in tight sandstone reservoirs and the optimization of huff-n-puff experiments subsequent to flooding.

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Dynamic characteristics and influencing factors of CO2 huff and puff in tight oil reservoirs

Cited by 27 publications

References 19 publications

Exploration Experiment of Development Method After Depletion of Tight Oil

Exploration Experiment of Development Method After Depletion of Tight Oil

Miscibility Characteristics of CO₂–Oil in Tight Sandstone Reservoirs: Insights from Molecular Dynamics Simulations

Microscopic Production Characteristics of Huff-n-Puff after CO₂ Flooding in Tight Oil Sandstone Reservoirs

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Dynamic characteristics and influencing factors of CO2 huff and puff in tight oil reservoirs

Cited by 27 publications

References 19 publications

Exploration Experiment of Development Method After Depletion of Tight Oil

Exploration Experiment of Development Method After Depletion of Tight Oil

Miscibility Characteristics of CO2–Oil in Tight Sandstone Reservoirs: Insights from Molecular Dynamics Simulations

Microscopic Production Characteristics of Huff-n-Puff after CO2 Flooding in Tight Oil Sandstone Reservoirs

Contact Info

Product

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Miscibility Characteristics of CO₂–Oil in Tight Sandstone Reservoirs: Insights from Molecular Dynamics Simulations

Microscopic Production Characteristics of Huff-n-Puff after CO₂ Flooding in Tight Oil Sandstone Reservoirs