Coke Formation and Coupled Effects on Pore Structure and Permeability Change during Crude Oil in Situ Combustion

Xu, Qianghui; Jiang, Hang; Zan, Cheng; Tang, Wenbin; Xu, Ruijun; Huang, Jia; Li, Yang; Ma, Dawei; Shi, Lin

doi:10.1021/acs.energyfuels.5b02600

Cited by 15 publications

(40 citation statements)

References 26 publications

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“…In this stage, the side-chain aliphatic hydrocarbon carbon of petroleum coke burns and gives off heat. According to the solid 13 C NMR spectrum of coke, 14 the content of saturated aliphatic hydrocarbon carbon in the petroleum coke formed at 500 °C in the case of sp 3 hybridization decreases significantly with the increase in coking temperature. When the final temperature rises to 678 °C, the pyrolysis process becomes strongly exothermic, which is the third stage of the exothermic reaction process.…”

Section: Resultsmentioning

confidence: 99%

Formation and Combustion Heat Release of Naphthenic-Based Crude Oil Cokes at Different Reaction Temperatures

Su¹,

Wang

Sun³

et al. 2022

ACS Omega

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Petroleum cokes prepared from naphthenic crude oil differ significantly in terms of the oxygen content and hydrogen/carbon (H/C) ratio, which mainly depend on the different coking temperatures. Thermogravimetric-differential scanning calorimetry was applied to study the heat release and combustion weight loss of petroleum cokes prepared at 350 and 500 °C, respectively. The effect of different coke formation temperatures on the combustion properties of the coke formed during air injection in situ combustion (ISC) was also investigated. The results showed that the petroleum coke formed under oxygen exhibited an H/C ratio of 0.895 and an O/C ratio of 0.109 at 350 °C and an H/C ratio of 0.395 and an O/C ratio of 0.054 at 500 °C. As the temperature rises, the hydrogen atoms on the petroleum coke molecules intensify to separate and form water molecules and thus giving off heat. It can be further inferred that under the combustion temperature of air injection ISC, the coke at 350 °C can release more heat in the lower combustion temperature range, and the combustion weight loss is faster; however, the formation temperature continues to rise due to combustion at 500 °C, coke begins to release massive heat, and the combustion weight loss is as high as 97.95%. The combustion residuals of both temperature cokes and the residual solid content of the formation after combustion in porous media are both little, which can be used as fire flooding fuels at different formation temperatures to provide heat energy for oil displacement.

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Section: Resultsmentioning

confidence: 99%

Formation and Combustion Heat Release of Naphthenic-Based Crude Oil Cokes at Different Reaction Temperatures

Su¹,

Wang

Sun³

et al. 2022

ACS Omega

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“…Alade et al (2019) investigated the changes in oil composition under combustion and a pyrolysis process (nitrogen gas injection) and concluded that combustion resulted in a higher conversion rate . Xu et al (2016) reported the impacts of in situ combustion on pore configurations and permeability . It was found that the coke deposition in pores turned large pores into micropores which deteriorated permeability.…”

Section: Css Follow-up Processes and Simulationmentioning

confidence: 99%

A Critical Review of Reservoir Simulation Applications in Key Thermal Recovery Processes: Lessons, Opportunities, and Challenges

Yang

Nie

et al. 2021

Energy Fuels

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After a cyclic steam stimulation (CSS) process achieved accidental success in recovering heavy oil resources in the 1960s, thermal recovery processes started to unlock the door of in situ recovery of heavy oil and bitumen resources. After five decades of development, many thermal recovery processes have been developed, among which CSS and steam-assisted gravity drainage (SAGD) are two main commercialized processes. With the support of laboratory and field data, reservoir simulation can help engineers and researchers to understand recovery mechanisms, optimize operations, and forecast performance of either existing or emerging processes. In this paper, we present a critical review of applications of reservoir simulation on CSS, CSS follow-ups (steamflooding, liquid addition to steam for enhancing recovery (LASER), and in situ combustion), SAGD, solvent-assisted SAGD, and SAGD noncondensable gas (NCG) coinjection processes. This review and the analyses of these processes provide not only their clarifications from thermal simulation lessons but also an extensive summary of challenges still faced by industry. Moreover, they shed light on future research directions and opportunities for thermal recovery processes.

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“…Normal fire flooding production can also be achieved, but the effective time of the surrounding production wells is delayed by 4-6 months [7,16]. This shows that the viscosity of heavy oil has a certain impact on the combustion dynamics and the injectionproduction parameters of fire flooding, which leads to high risk and difficulty to grasp the economy of high-viscosity heavy oil fire flooding [17]. The goals of this study were to conduct one-dimensional combustion tube tests using heavy oil with different viscosities and to clarify the influence of the viscosity on the temperature, gas composition, air injection pressure, and production parameters of fire flooding in order to provide a basis for the formulation of a highviscosity oil reservoir fire flooding plan and the construction of supporting oilfield facilities.…”

Section: Introductionmentioning

confidence: 99%

Study of Displacement Characteristics of Fire Flooding in Different Viscosity Heavy Oil Reservoirs

Liu¹,

Liu²,

Zhao

et al. 2021

Geofluids

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A field test in the Xinjiang oilfield in China shows that the viscosity of heavy oil has a certain influence on the combustion dynamics and injection-production performance of fire flooding. The experiment in this study uses a one-dimensional combustion tube to study the temperature, gas composition, and air injection pressure and the production performance of the fire flooding of heavy oil with different viscosities. The results show that the oil viscosities of 1180–22500 mPa·s can achieve stable combustion, and the O2 content of the gas produced during the stable combustion stage is <0.5%. The higher the viscosity of the heavy oil, the higher the temperature in the burned zone and the smaller the range of the temperature increase in the unburned zone. The air injection pressure will increase rapidly until a stable seepage channel is formed, and then, it will drop to a level close to the formation pressure. High-viscosity heavy oil requires a higher air injection pressure and will remain in the high-pressure stage for a longer period of time. Low-viscosity heavy oil has a low water cut in the early stage of fire flooding, a large oil production rate, and a low and stable air–oil ratio. The water cut of high-viscosity heavy oil increases rapidly in the early stage of fire flooding and then decreases gradually, so a good air–oil ratio can only be obtained in the middle and late stages of fire flooding. Thus, fire flooding may be more suitable for application in common heavy oil and some extra heavy oil reservoirs with lower viscosities.

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Coke Formation and Coupled Effects on Pore Structure and Permeability Change during Crude Oil in Situ Combustion

Cited by 15 publications

References 26 publications

Formation and Combustion Heat Release of Naphthenic-Based Crude Oil Cokes at Different Reaction Temperatures

Formation and Combustion Heat Release of Naphthenic-Based Crude Oil Cokes at Different Reaction Temperatures

A Critical Review of Reservoir Simulation Applications in Key Thermal Recovery Processes: Lessons, Opportunities, and Challenges

Study of Displacement Characteristics of Fire Flooding in Different Viscosity Heavy Oil Reservoirs

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