Underground Upgrading of Heavy Oil Using THAI—''Toe-to-Heel Air Injection''

Gréaves, M.; Xia, Tian; Ayasse, Conrad

doi:10.2118/97728-ms

Cited by 33 publications

(10 citation statements)

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“…Exploitation of heavy (HO) and extra-heavy crude oils (EHO) is still facing several challenges due to their high density and viscosity, which cause low mobility in porous media. , Hence, many thermal recovery methods were developed. − These methods are classified mainly into two types that are widely known as steam injection and in situ combustion (ISC). , During steam injection, heavy oil extraction is accomplished by periodical or continual injection of steam that builds up heat, which is transferred to the adjacent area, reducing the viscosity of the HO and subsequently mobilizing it or generating heat, which allows the flow to surface. This process is known to consume a lot of energy and water .…”

Section: Introductionmentioning

confidence: 99%

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C₇ Asphaltenes under High-Pressure Conditions

et al. 2020

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Effects of pressure on thermo-oxidative decomposition of different sources of n-C7 asphaltenes were investigated at high pressure using a thermogravimetric analyzer under an air atmosphere. The n-C7 asphaltenes were extracted from different heavy and extra-heavy crude oils around the world and were thoroughly characterized by elemental analysis (EA), vapor pressure osmometry (VPO), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) techniques. A high-pressure thermogravimetric analyzer coupled to a mass spectrometer was employed to obtain thermograms at 0.084, 3.0, and 6.0 MPa, and gaseous products were obtained by asphaltene decomposition. Kinetic analyses were performed for thermo-oxidative multistep reactions and compared based on the trends of pre-exponential factor and effective activation energies using an approximation of the Ozawa, Flynn, and Wall (OFW) isoconversional method. The n-C7 asphaltene decomposition profile was determined by four thermal events, namely, oxygen chemisorption (OC), desorption/decomposition of chemisorbed oxygen functional groups (DCO), and first and second combustion (FC and SC, respectively). We found that the amount of chemisorbed oxygen depends not so much on the oxygen percentage present in the n-C7 asphaltenes and aggregates but on whether it is found in a greater proportion as COO groups, independent of the used pressure. In addition, as the aromatization degree increases and the alkylation degree decreases, the amount of oxygen atoms chemisorbed also increases. As for the DCO region, it was corroborated that the increase in pressure from 0.084 to 6.0 MPa has a positive influence on the mass loss in this region for all samples used. The n-C7 asphaltenes with a higher chemisorption in the previous region showed a higher decomposition or loss of oxygenated compounds during DCO because there are more oxygenated groups in the basal plane of aromatic structures; therefore, the kinetics of the carbonaceous material consumption is increased. According to XPS analysis, n-C7 asphaltenes with a higher content of sulfur as thioethers show facilitated decomposition, due to the low energy required for their oxidation and subsequent cracking, throughout the range of evaluated pressures. Further, the higher content of hydrogen on α carbons to aromatic rings suggests that some of their small alkyl side chains are cracked in this zone due to the easy decomposition of α-methyl, α-methylene, and α-methine structures. As for the FC region, up to 3.0 MPa, a greater mass loss occurs in n-C7 asphaltenes with a high content of short aliphatic chains. Nevertheless, at 6.0 MPa, the mass loss percentage decreases in similar measures for all samples, indicating that under these conditions there is greater ease of breaking the functional groups located both in the basal plane of the aromatic rings and on the periphery of the molecule. Finally, during high-temperature oxidation reactions (SC), the higher a...

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Section: Introductionmentioning

confidence: 99%

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C₇ Asphaltenes under High-Pressure Conditions

et al. 2020

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“…Thermal-enhanced oil recovery (EOR) processes for heat injection in to the reservoir include in situ combustion (ISC) − and low-temperature oxidation (LTO) methods, − which involve the injection of an oxidizing agent (air or oxygen) in to the target formation for a defined period . During the ISC, the oxidizing agent is activated by specialized tools, pyrophoric substances, steam, or by the same reactivity of the oil by burning a portion of the same. , In this burned area, a heat front is formed that pushes the rest of the hydrocarbons through a combination of the combustion gases, steam, and water to the producing wells.…”

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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“…Table shows some features of our database. The set includes SARA analyses reported in 108 public papers found in open and private literature. ,− …”

Section: Methodsmentioning

confidence: 99%

Estimation of the SARA Composition of Crude Oils from Bubblepoint Pressure Data

Reyes-Gonzalez¹,

Ramírez-Jaramillo

Manero³

et al. 2016

Energy Fuels

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A statistical correlation to provide reasonable estimates of crude oiĺs SARA compositions (saturates, aromatics, resins, asphaltenes) from bubblepoint pressure and light-ends compositional data is presented. In developing the correlation, we collected experimental SARA compositions of 341 crude oils of different origin. The most-probable SARA compositions are then obtained by seeking the maximum probability according to its oil type, in line with the measured values of bubblepoint pressures. Results show that the proposed method is simple and provides reasonable values of SARA compositions of an oil in cases in which only the light-ends compositions and a few bubblepoint pressures are available.

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Underground Upgrading of Heavy Oil Using THAI—''Toe-to-Heel Air Injection''

Cited by 33 publications

References 3 publications

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C₇ Asphaltenes under High-Pressure Conditions

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C₇ Asphaltenes under High-Pressure Conditions

Effect of Pressure on the Oxidation Kinetics of Asphaltenes

Estimation of the SARA Composition of Crude Oils from Bubblepoint Pressure Data

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Underground Upgrading of Heavy Oil Using THAI—''Toe-to-Heel Air Injection''

Cited by 33 publications

References 3 publications

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C7 Asphaltenes under High-Pressure Conditions

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C7 Asphaltenes under High-Pressure Conditions

Effect of Pressure on the Oxidation Kinetics of Asphaltenes

Estimation of the SARA Composition of Crude Oils from Bubblepoint Pressure Data

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Product

Resources

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Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C₇ Asphaltenes under High-Pressure Conditions

Thermo-Oxidative Decomposition Behaviors of Different Sources of n-C₇ Asphaltenes under High-Pressure Conditions