Study on heavy oil components transformation path based on core analysis during in-situ combustion process

Yuan, Shibao; Jiang, Haiyan; Shi, Yaoli; Ren, Zongxiao; Wang, Jiao; Zhang, Yupeng

doi:10.1016/j.fuel.2019.04.135

Cited by 18 publications

(10 citation statements)

References 5 publications

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“…In addition, cracking reduced the oil viscosity, increasing oil mobility and improving the production capacity . During these processes that are carried out under high-pressure conditions, a series of chemical reactions, such as oxidation, catalytic disintegration, and distillation, are generated mainly with the heaviest fraction of the crude oil. ,, Asphaltenes are the main precursor of the solid part formed from thermal cracking reactions named coke, that is, they are the main fuel to generate a high-temperature oxidation (HTO) reaction also known as breaking reactions or simply combustion reactions . As the amount of injected air that reacts with the coke increase, a flame or combustion front is generated.…”

Section: Introductionmentioning

confidence: 99%

Effect of Pressure on the Oxidation Kinetics of Asphaltenes

et al. 2019

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This study was carried out with the aim of evaluating the effect of the high pressure on the oxidation kinetics of n-heptane-insoluble asphaltenes, obtained from an extra-heavy crude oil. Thermogravimetric analyses (TGA) were performed under an air atmosphere, at different pressures from 0.084 to 7 MPa, and temperatures from 100 to 600 °C at different heating ramps of 5, 10, and 15 °C min −1 . The effective activation energy and the kinetic parameters were obtained using a first-order kinetic model, which indicated a pressure-dependent behavior. For a better understanding of the asphaltene oxidation under high-pressure conditions, the temperature range in which the oxidation process was carried out was divided in to four main regions according to the TGA profile, namely: (i) oxygen chemisorption (OC), (ii) decomposition of the chemisorbed oxygen (DCO), (iii) first combustion (FC) region, and (iv) second combustion (SC) region. It was observed that the increase of pressure favors the asphaltene decomposition as the percentages of mass loss in the first combustion region are 20% at 0.084 MPa and 50% at 7 MPa. Furthermore, the temperature at which each thermal event ends is reduced by approximately 35, 23, 13, and 51 °C from 0.084 to 7 MPa for OC, DCO, FC, and SC, respectively. Also, by increasing the heating rate, the decomposition of the asphaltene in the second combustion region is increased, indicating that the decomposition follows different mechanisms depending on the exposure time. On the other hand, with the increase in the system pressure, an increase of 53.1 and 71.1% of the effective activation energy values was observed for the thermal events associated to oxygen chemisorption and decomposition of chemisorbed oxygen, respectively, while for the combustion (FC and SC) stages, the activation energy decreases by 61.4 and 75.6%, respectively, indicating that the asphaltene oxidation behavior is controlled by the pressure in the four regions. All of these facts show that the kinetic limiting step for the asphaltene oxidation is the chemisorption of the oxygen, which is favored by the increase of the pressure.

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Section: Introductionmentioning

confidence: 99%

Effect of Pressure on the Oxidation Kinetics of Asphaltenes

et al. 2019

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“…In petroleum engineering, cement-based materials have been used to isolate the stratum and protect the metal casing. − However, the complex conditions of oil and natural gas wells, i.e., high temperatures and pressures, among other factors, can strongly affect the structural integrity and mechanical properties of the cement paste. − Particularly, In the heavy oil thermal recovery process, cement paste usually experiences the cyclic elevated temperature and steam (CETS) of steam stimulation (SS), the elevated temperature and steam (ETS) of steam driving (SD), and the high-concentration CO 2 (HCC) of in situ combustion conditions in sequence . Researchers generally believe that understanding the effects of the CETS, ETS, and HCC conditions of heavy oil thermal recovery on the microstructure and properties of the cement paste is very important for designing the cement slurry of heavy oil cementing and ensuring the integrity of the cement sheath. ,, …”

Section: Introductionmentioning

confidence: 99%

“…4−10 Particularly, In the heavy oil thermal recovery process, cement paste usually experiences the cyclic elevated temperature and steam (CETS) of steam stimulation (SS), the elevated temperature and steam (ETS) of steam driving (SD), and the high-concentration CO 2 (HCC) of in situ combustion conditions in sequence. 11 Researchers generally believe that understanding the effects of the CETS, ETS, and HCC conditions of heavy oil thermal recovery on the microstructure and properties of the cement paste is very important for designing the cement slurry of heavy oil cementing and ensuring the integrity of the cement sheath. 4,12,13 In the exploitation of heavy oil, the SS technique increases the reservoir temperature and reduces the viscosity of the heavy oil by injecting steam with an elevated temperature of 300−320 °C repeatedly into the heavy oil reservoir.…”

Section: Introductionmentioning

confidence: 99%

Granular Calcium Carbonate Reinforced the Cement Paste Cured by Elevated Temperatures

Liu

2023

ACS Omega

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In a heavy oil thermal recovery well, cement paste experiences the cyclic elevated temperature and steam of steam stimulation, the elevated temperature and steam of steam driving, and the high-concentration CO2 (HCC) of in situ combustion conditions in sequence. To understand the effects of different conditions of heavy oil thermal recovery wells on the properties and microstructure of the cement paste, this paper investigated the influence of the cyclic elevated temperature, elevated temperature, and high-concentration CO2 conditions on the compressive strength of the cement paste. Then, low-field nuclear magnetic resonance, scanning electron microscopy, and X-ray diffraction were used to test the pore structure, microstructure, and crystal type of the cement paste cured under different conditions. Experimental results showed that the elevated temperature curing loosened the microstructure of the cement paste and increased its pore size and porosity, resulting in reducing the compressive strength to 21.04 MPa, compared with that of the cement paste at cyclic elevated temperature. For the cement paste cured under high-concentration CO2 conditions, the calcium hydroxide and calcium-silicate-hydrate reacted with CO2 to generate granular vaterite, aragonite, and calcite in the pores and cracks, which repaired the cement paste by reducing the porosity and pore size of the cement paste and increasing its compressive strength. When the carbonation time increased to 28 days, the cement paste was completely carbonized, and the compressive strength of the cement paste increased by approximately 169%, compared with that of the cement paste cured at an elevated temperature.

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“…A low temperature at the initial period propagates an unreacted oxygen front, which is unfavourable for combustion (Xu et al, 2018). So, the oxygenation of the heavy oil increases the temperature in the reservoir in the burnt zone (Yuan et al, 2019). As the thermal front reaches the downstream of the burning zone, an enormous amount of heat energy is released from the combustion of crude oil with air.…”

Section: Introductionmentioning

confidence: 99%

Comparative Analysis on Impact of Water Saturation on the Performance of in-Situ Combustion

Pavan

Devarapu

Govindarajan

2022

MGPB

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The amount of oil together with the water Originally in Place (OIP), makes up the liquid phase in heavy oil reservoir systems. This amount of liquid present in the pores of the reservoir system is known as liquid saturation, plays a vital role in improving oil recovery through In-Situ Combustion (ISC) process. The oil phase acts as fuel in generating thermal energy required for viscosity reduction and the water phase supports in the formation of an enlarged condensation zone that aids in higher mobility of the low viscous oil. A numerical investigation is carried out to study the role of water saturation on the performance of in-situ combustion in a heavy oil reservoir. A finite-difference based numerical model is developed and validated for water recovery. The model is then used to carry out the impact of liquid saturation on the performance of the ISC, as it plays a vital role in screening criteria for the selection of ISC. The numerical results projected a significant effect on the thermal and production profile during the process. A comparison between the effect of variation in water and oil saturations projected a significant increase in reservoir temperatures with increased water saturation than the oil saturation. The highest reservoir temperatures are observed at the maximum liquid (oil and water together) saturation. Further, the additional water drive provided by increased water saturation is observed to contribute to early production rates.

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Study on heavy oil components transformation path based on core analysis during in-situ combustion process

Cited by 18 publications

References 5 publications

Effect of Pressure on the Oxidation Kinetics of Asphaltenes

Effect of Pressure on the Oxidation Kinetics of Asphaltenes

Granular Calcium Carbonate Reinforced the Cement Paste Cured by Elevated Temperatures

Comparative Analysis on Impact of Water Saturation on the Performance of in-Situ Combustion

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