Accelerating Rate Calorimeter Tests Research Articles

Effect of fast charging on degradation and safety characteristics of lithium-ion batteries with LiFePO4 cathodes

Fast charging compatibility is a desirable feature for batteries to shape a promising future in our rechargeable world. Enabling fast charging of advanced energy-dense Li-ion batteries for growing electric vehicle (EV) markets depends on the breakthrough of material chemistry and optimization of charging strategy. Lithium iron phosphate (LiFePO4, or LFP) is a pivotal cathode material in state-of-the-art EV batteries due to the merits of high thermal stability, long cycle lifetime, and high-temperature performance. However, degradation-safety interactions of LFP-based Li-ion batteries under fast charging conditions and low temperatures remain elusive. In this study, we cycle LFP cells under different fast charging strategies and thermal environments to understand their effects on degradation pathways, where the capacity, voltage, temperature, coulombic inefficiency, internal resistance, and impedance spectroscopy are evaluated. Half-cell studies are implemented to assess electrode-level capacity retentions. Post-mortem analyses are conducted to reveal physicochemical changes in electrodes. Accelerating rate calorimeter tests are carried out to measure evolutions of cell-level thermal instabilities after fast charging tests. This research article highlights the significant roles of graphite-centric lithium plating and LFP-centric transition metal dissolution in driving substantial electrochemical degradations, suggesting that a mild low temperature does not necessarily reduce the LFP cell lifetime.

Modeling thermal runaway of lithium-ion batteries with a venting process

Thermal runaway poses a critical challenge for the safety of electric vehicles powered by lithium-ion batteries. A series of drastic exothermic reactions take place with gas generation during thermal runaway, making it challenging to accurately model the process. In this work, we present a reliable lumped thermal runaway model by incorporating heat transfer and gas generation reactions based on an experimentally kinetic analysis. The proportions of reactants in 18,650 lithium-ion batteries are determined by disassembling the batteries and weighing the components, while the reaction frequencies and activation energies of gas generation reactions are identified through the thermal gravity analysis tests on the anode and cathode components using Kissinger’s method. The reaction kinetic equations are then combined with energy and mass conservation equations to form the thermal runaway model, which is validated against accelerating rate calorimeter tests. Simulation results show that it is the pressure rather than temperature that triggers the ejection. Therefore, gas generation that can depict the internal gas change should be included in the model to accurately predict the time of the battery venting. Moreover, it is revealed that when the safety pressure increases from 1600 to 2400 kPa, although the venting moment delays from 4294 to 4465 s, the thermal runaway takes place 54 s earlier. Hence, an appropriate safety pressure design range is suggested to be 1800–2200 kPa. This work develops a robust thermal runaway model and offers new insights into the mechanisms of thermal runaway, which provides valuable guidance for the thermal safety design of lithium-ion batteries.

Characterisation of thermal runaway behaviour of cylindrical lithium-ion battery using Accelerating Rate Calorimeter and oven heating

In this work, thermal runaway of lithium-ion battery was characterised under adiabatic and non-adiabatic conditions using Accelerating Rate Calorimeter (ARC) and oven respectively. Battery with higher electrical capacity demonstrated a higher tendency to experience thermal runaway with shorter induction time and resulted with a more energetic response, as indicated by higher maximum temperature rise. Oven tests at 190 °C were able to capture thermal runaway characteristics in batteries with 100% state-of-charge (SOC) only and resulted in a maximum temperature of 738–783 °C. Two batteries were more inclined to suffer thermal runaway as the induction time was reduced by 8.6% to 115.98 min, compared to 126.92 min for single cell. A further inclined by 15% to 107.72 min was recorded for two batteries with parallel electrical connection. Meanwhile, ARC was able to induce thermal runaway in 50% SOC battery and instigated exothermic thermal decomposition in 0% SOC battery due to the longer heating process. The maximum temperatures recorded from ARC tests were between 404 and 522 °C, lower than oven tests since some of the battery energy content was released slowly during the long self-heating period, leaving the battery with less energy for rapid release during thermal runaway.

Facile synthesis of three kinds triazole salts of 2,4,5-trinitroimidazole and their thermal decomposition properties

ABSTRACT In this paper, 1,2,4-triazolium 2,4,5-trinitroimidazolate (2), 3-amino-1,2,4-triazolium 2,4,5-trinitroimidazolate (3) and 4-amino-1,2,4-triazolium 2,4,5-trinitroimidazolate (4) were synthesized based on the method of acid-base neutralization and precipitation, which is a simple method compared with the method in Gao’s literature. These compounds were characterized by FT-IR, NMR, elemental analysis. The structure of (2) was further confirmed by single-crystal X-ray diffraction. Thermal decomposition performances of (2)-(4) were tested using differential scanning calorimetry (DSC) and accelerating rate calorimeter (ARC). The DSC curves of (2)-(4) show that they all have good thermal stability and the order of thermal stability is (4) > (2) > (3). ARC test data calculation results show that the thermal stability of (2)-(4) is (3) > (2) > (4). The test results show that the thermal stability of compounds (2)-(4) under non-adiabatic and adiabatic conditions was quite different. The storage temperature of (2), (3) and (4) does not exceed 420.93 K, 435.78 K, and 393.69 K, respectively, and they will not undergo self-accelerating decomposition.

Fullerene bisadduct stabilizers: The effect of different addition positions on inhibiting the autocatalytic decomposition of nitrocellulose absorbed nitroglycerin

To explore the effect of different positions and number of pyrrolidine bound to the carbon cage on the stabilization effect of fulleropyrrolidine derivatives to nitrocellulose (NC)/nitroglycerine (NG), we synthesized N-(4-methoxy) phenylpyrrolidine-C60 and four different of bis(N-(4-methoxy) phenylpyrrolidine)-C60 compounds through Prato reaction. Their structures were characterized by UV–vis, 1H NMR, 13C NMR, high-resolution mass spectroscopy, and single-crystal X-ray diffraction. Their stabilization effect to NC/NG were investigated using differential scanning calorimetry, methyl violet, vacuum stabilization effect, weight loss, and accelerating rate calorimeter tests. The results indicated these compounds had excellent stabilization effect to NC/NG. The stabilization effect of the fulleropyrrolidine bisadducts to NC/NG is significantly better than that of fulleropyrrolidine monoadduct and C60. Moreover, the position where pyrrolidine binds to fullerene in fulleropyrrolidine bisadducts is different, and its stabilization effect to NC is also different. The stabilization effect order of different bisadduct isomers to nitrocellulose is as follows: e-edge > trans-2> cis-2> trans-3. Electron paramagnetic resonance (EPR) and FT-IR were used to study the stabilization mechanism of fulleropyrrolidine derivatives to NC/NG. The EPR results also show that fulleropyrrolidine bisadducts with different addition sites have different abilities to absorb nitroxide, and their ability is better than that of the monoadduct and C60, which is consistent with the results of stabilization effect performance test.

Numerical modeling on thermal runaway triggered by local overheating for lithium iron phosphate battery

The popularization of electric vehicles is no longer a speculation thanks to the advancement of the lithium-ion battery. However, safety issues prevent a larger-scale application of lithium-ion batteries. In energy storage industry, thermal runaway is the direct cause of fire and explosions. The thermal runaway numerical model attempts to unveil the mechanism of thermal runaway triggered by local overheating in this work, which is distinct from accelerating rate calorimeter tests or oven tests. The model is based on the energy conservation equation, and the source term of which is modeled by the empirical Arrhenius equations. Further on, the results of the numerical model are validated by experiments. Based on the calculated analysis on the heat contribution to the thermal runaway, the heat contribution of anode-electrolyte reaction is up to 63.8% of the total heat, and internal short circuit is responsible for a little proportion of total heat generation during thermal runaway which is contrary to the general thoughts, yet still a crucial inducement of chain reactions. The results also confirm the conclusion that enhancement of heat dissipation condition of battery can retard thermal runaway progress and reduce the maximum thermal runaway temperature. In addition, interior dynamic temperature distribution of the battery can be achieved, and characteristics of local overheating are compared with those of oven tests, noteworthy temperature difference in local overheating occasion is highlighted.

A Simplified Mathematical Model for Heating-Induced Thermal Runaway of Lithium-Ion Batteries

The present study aims to develop a simplified mathematical model for the evolution of heating-induced thermal runaway (TR) of lithium-ion batteries (LIBs). This model only requires a minimum number of input parameters, and some of these unknown parameters can be obtained from accelerating rate calorimeter (ARC) tests and previous studies, removing the need for detailed measurements of heat flow of cell components by differential scanning calorimetry. The model was firstly verified by ARC tests for a commercial cylindrical 21700 cell for the prediction of the cell surface temperature evolution with time. It was further validated by uniform heating tests of 21700 cells conducted with flexible and nichrome-wire heaters, respectively. The validated model was finally used to investigate the critical ambient temperature that triggers battery TR. The predicted critical ambient temperature is between 127 °C and 128 °C. The model has been formulated as lumped 0D, axisymmetric 2D and full 3D to suit different heating and geometric arrangements and can be easily extended to predict the TR evolution of other LIBs with different geometric configurations and cathode materials. It can also be easily implemented into other computational fluid dynamics (CFD) code.

Thermal Safety Performance Evaluation for Typical Free Radical Polymerization Initiator of Tert‐butyl Peroxypivalate

AbstractTert‐butyl peroxypivalate is a typical free radical polymerization initiator due to the active O−O peroxide group, and it is a thermal instability material. To evaluate the thermal safety of tert‐butyl peroxypivalate, Dewar test, Differential Scanning Calorimetry (DSC) and Accelerating Rate Calorimeter (ARC) were used to study the self‐accelerating decomposition temperature (SADT), thermal performance parameters and kinetic parameters. The results of DSC reveal that the onset decomposition temperature of the initiator was 76.30 °C. The apparent activation energy (Ea) was 91.86 kJ mol−1 by Kissinger method. In ARC test, the onset decomposition temperature was 40.64 °C. The adiabatic temperature of the reaction was 86.68 °C, and the apparent activation energy was 120.14 kJ mol−1. The results of Dewar test show that the SADT of the initiator was 38 °C. The simulated SADT value by thermal analysis software (AKTS) was about 35 °C which was basically consistent with the results of Dewar test.

Thermal decomposition and thermal kinetic simulation of ammonium 3,3′-dinitrimino-5,5′-bis(1H-1,2,4-triazole)

Ammonium 3,3′-dinitrimino-5,5′-bis(1H-1,2,4-triazole) (ADNABT) was synthesized and characterized by IR spectroscopy, 1H/13C NMR and single-crystal X-ray diffraction. The thermal decomposition of ADNABT was investigated by thermogravimetry–differential thermal analysis (TG–DTA) and accelerating rate calorimeter (ARC). The kinetic parameters (activation energy, pre-exponential factor, mechanism functions) by DTA and ARC tests were simulated by Thermal Safety Software (TSS). The simulated results revealed that the exothermic decomposition of ADNABT under non-isothermal and adiabatic conditions all followed a full autocatalysis model. In order to ensure the safety of production, transportation and storage, several thermal hazard indicators such as time to maximum rate (TMR), reaction temperature at which TMR is 24 h (TD24), time to conversion limit and self-accelerating decomposition temperature (SADT) were also simulated by TSS on the kinetic model. The TD24 and SADT50 kg were calculated as 183.37 and 167.00 °C, respectively.

Thermal decomposition kinetics and thermal hazards simulation of sodium and rubidium 3,3′-dinitrimino-5,5′-bis(1H-1,2,4-triazole)

Sodium 3,3′-dinitrimino-5,5′-bis(1H-1,2,4-triazole) (Na2DNABT) and rubidium 3,3′-dinitrimino-5,5′-bis(1H-1,2,4-triazole) (Rb2DNABT) were synthesized and characterized by IR spectroscopy and 1H/13C NMR. Rb2DNABT was characterized by single-crystal X-ray diffraction. The thermal decomposition kinetics and thermal hazards of Na2DNABT and Rb2DNABT were investigated by difference scanning calorimeter (DSC) and accelerating rate calorimeter (ARC). The thermal decomposition kinetics (activation energy, pre-exponent, reaction model) were evaluated by Thermal Safety Software (TSS) on DSC and ARC tests. The activation energy of Na2DNABT and Rb2DNABT by DSC test was also calculated by Starink method, which consistent with the simulated activation energy by TSS. Time to maximum rate (TMR), reaction temperature at which TMR is 24 h (TD24) and time conversion limit (TCL) were simulated by TSS, too. The TD24 of Na2DNABT and Rb2DNABT were calculated as 215.86 and 141.95 °C, respectively, and their TCL at 200 °C was calculated as 24.00 and 4.56 h, respectively. Na2DNABT is a stable and safety compound compared with Rb2DNABT.

The Thermal Stability of Lithium Solid Electrolytes with Metallic Lithium

Summary All-solid-state lithium-metal batteries are regarded as promising next-generation battery systems. While thermal runaway in conventional Li-ion batteries is known to cause safety hazards, the thermal issues posed by highly reactive metallic lithium (Li) with non-flammable ceramic solid electrolytes (SEs) have been less studied but are critical for the safety of all-solid-state Li-metal batteries. Here, we quantify the thermal stability of four prevalent oxide SEs with metallic Li using the accelerating rate calorimeter (ARC). Thermal runaway is observed during ARC tests for four widely used SEs when contacting with Li, while no obvious heat releases from garnet with Li. The oxygen generation from SEs at elevated temperatures is found to be responsible for the thermal runaway with Li. Our results indicate potential safety issues in all solid-state batteries (ASSBs) brought by highly reactive metallic Li and oxygen from SEs at increased temperatures, emphasizing the need for investigating thermal safety issues in ASSBs.

(Invited) Changes in Thermal Stability of Cyclic Aged Commercial Lithium-Ion Cells

It is well-known that lithium-ion cells can have safety issues. A large number of battery fire incidents have been reported. Of the more famous ones are fires in the APU battery of Boeing Dreamliner [1], fires in the Chevrolet Volt battery [2] and the Samsung Galaxy Note 7 recall (2016). Thermal stability is one of several factors affecting the safety aspects of lithium ion cells. The thermal stability for uncycled cell materials and cells is well-documented, but the effect of cyclic ageing on thermal stability is far less studied [3-6] and only in 18650 sized cells. In this presentation, we describe a systematic approach on how different temperature and current loads are affecting the thermal stability during cyclic aging of three different sized commercial cylindrical lithium-ion power cells. The cells were heated in an Accelerating Rate Calorimeter (ARC) with a heat-wait-seek procedure and temperature steps of 5 °C. Decrease in thermal stability was found in all three cyclic ageing test series as a function of relative high current and low temperature (5 °C) even though the cells were tested within the limits specified by the cell manufacturers. The decrease in thermal stability was minor for one of the test series but rather large and potentially dangerous for the other two test series. As a result, one of the cells with decreased thermal stability experienced severe disintegration of the cell can during the ARC test. A picture of the disintegrated cell that was cycled at 5 °C and 1C/1C condition is presented in Figure 1. New and potentially dangerous safety related alterations have been found in cyclic aged lithium-ion batteries. The decrease in thermal stability could be dangerous and should be an end of life criteria. An uncycled cell in a battery module may withstand the heat from a neighboring thermal runaway cell, while a cycled cell may be driven into thermal runaway. It is of vital importance to develop new diagnostic tools capable of detecting a dangerous drop in thermal stability in cyclic aged lithium-ion cells. Auxiliary Power Unit Battery Fire, Japan Airlines Boeing 787-8, JA829J, Boston, Massachusetts, January 7, 2013. . 2014, National Transportation Safety Board.Smith, B., Chevrolet Volt Battery Incident Overview Report. 2012, NHTSAFleischhammer, M., et al., Interaction of cyclic ageing at high-rate and low temperatures and safety in lithium-ion batteries. Journal of Power Sources, 2015. 274: p. 432-439.Börner, M., et al., Correlation of aging and thermal stability of commercial 18650-type lithium ion batteries. Journal of Power Sources, 2017. 342: p. 382-392.Friesen, A., et al., Impact of cycling at low temperatures on the safety behavior of 18650-type lithium ion cells: Combined study of mechanical and thermal abuse testing accompanied by post-mortem analysis. Journal of Power Sources, 2016. 334: p. 1-11.Friesen, A., et al., Al2O3 coating on anode surface in lithium ion batteries: Impact on low temperature cycling and safety behavior. Journal of Power Sources, 2017. 363: p. 70-77 Figure 1

Effect of inorganic salt and organic acid on the thermal runaway of hydrogen peroxide

Hydrogen peroxide with the presence of catalytic metal ions or incompatible organic matters has caused some fire and explosion accidents in recent years. This work further studied the effect of inorganic salt and organic acid on the thermal runaway behaviour of hydrogen peroxide via rapid screening device (RSD), accelerating rate calorimeter (ARC) and a batch reactor. Experimental results revealed that both the metal ions and their corresponding inorganic acid ions have significant influences on the thermal runaway of H2O2: the catalytic effect of metal ion followed Fe2+ > Fe3+ > Cu2+, and the synergistic effect of inorganic acid ion followed Cl− > SO42−. No explosion was detected under RSD and ARC test conditions. In addition, a one-step global reaction kinetic model characterized as adiabatic temperature increase and final exothermic temperature was briefly described to estimate the kinetic parameters of the mixture of H2O2 with/without organic acid. The analysis showed that the runaway reaction of H2O2 with formic acid or acetic acid is a first order reaction at a low temperature range (<100 °C) and the thermal runaway risk of H2O2/HCOOH > H2O2/CH3COOH, along with the decreasing apparent activation energy and pre-exponential factor.

Vapor-Phase Combustion in Accelerating Rate Calorimetry for Air-Injection Enhanced-Oil-Recovery Processes

Summary The accelerating rate calorimeter (ARC) is unique for its versatility of operation and application—reliability, validity, and accuracy of results—caused by very-high adiabaticity. Accelerating rate calorimetry is one of the screening tests used to determine the suitability of a reservoir for air-injection enhanced oil recovery. The ARC is well-suited for investigating the reaction mechanisms in the low-temperature range (LTR), negative-temperature-gradient region (NTGR), and high-temperature range (HTR). The ARC provides full time–temperature, time–pressure, and self-heat rate-inverse absolute-temperature profiles. An experimental and simulation study is carried out to expand knowledge and interpretation of the data derived from high-pressure closed ARC tests. Athabasca bitumen is used for the experimental study in a closed ARC at an initial pressure of 13.8 MPag (2,000 psig) to identify the nature of the oxidation reactions occurring over the different temperature ranges. The simulation component of the study focused on the development of a numerical model that captured the elements of the ARC test. The model incorporated solubility of oxygen and diffusion to control the transfer of oxygen in the liquid-oil phase. Mass transfer is found to play an important role at low temperatures up to the temperature at which chemical interaction starts to control the distribution of oxygen within the liquid bitumen. Likewise, vaporization of oil and generation of vapor by cracking reactions are also believed to play an important role in air-injection processes. Therefore, a vapor-phase combustion reaction is integrated into the traditional Belgrave kinetic model. This modified model predicted that the combustion of vaporized oil integrated with its flammable limits and the rate of diffusion of the vaporized component in the gas phase. The results of this study indicate that, with the addition of mass transfer to the kinetic model, it is possible to predict the NTGR. The result showed that solubility and diffusion of oxygen played an important role up to a temperature of 125°C at which chemical reactions started to control the distribution of oxygen within the liquid bitumen. The results also showed that vapor-phase combustion creates a temperature gradient between the gas and bitumen phases when vaporized components became flammable (stoichiometry). This showed that the ARC could be an effective tool for understanding liquid and vapor-phase reaction and their relative importance in different temperature regimes.

Characterization of Safety Aspects of Li-Ion Batteries for Maritime Applications

Electrical cars and consumer electronics use since several years back Li-ion batteries as electrical energy storage. This means that the Li-ion battery technology is mature enough for these applications. However, in maritime applications there are some issues to be solved, especially related to safety. The battery will be in a confined space and in many cases be much larger. In addition to having high energy density, Li-ion batteries contain combustible material and most of the chemistries do also release oxygen[1] [2] [3]. Flammable gases such as hydrogen, carbon monoxide, methane, ethane etc. are also released up on heating[4]. Heating of the battery can be caused by internal flaws, e.g. particles from the cell production[5] and poor battery management design as well as external incidents such as fire. In order to ensure a safe electrical/hybrid electrical power vessel, all data from electrical and safety tests (on cell and battery level) should be considered as a database of information. This information is vital to ensure a proper design of the battery and the battery room for the vessel in question. Included in the battery room design are the physical dimensions of the room and systems for mitigating the consequences of a battery vent, battery fire and possible gas explosion. There are many factors that affect the safety of lithium-ion cells, such as chemistry, size, geometry and cell environments. Aging and cycling could also affect the safety properties. We have studied the thermal response of batteries during controlled heating (calorimetric techniques). Amongst the techniques used in our study is controlled heating by the use of an Accelerating Rate Calorimeter (ARC). In this case the size, geometry and cell environment have been kept constant, while different battery chemistries are varied. The results obtained from the ARC tests on new 18650 cells show that the highest heat rate does not necessarily correspond to the most severe physical result. The results from aged and cycled cells will also be discussed. [1] MacNeil, D.D. and J.R. Dahn, The Reaction of Charged Cathodes with Nonaqueous Solvents and Electrolytes: I. Li 0.5CoO2. Journal of The Electrochemical Society, 2001. 148(11): p. A1205. [2] Arai, H., et al., Thermal Reactions Between Delithiated Lithium Nickelate and Electrolyte Solutions. Journal of The Electrochemical Society, 2002. 149(4): p. A401. [3] Doughty, D.H., A general discussion of lithium ion battery safety, in The Electrochemical Society Interface. 2012. p. 37-44. [4] Rothe, E.P. 19, s-l.: ESC Translations, 2008, Vol.11, pp.19-41. 10.1149/1.2897969 [5] Aircraft Incident Report, Auxiliary Power Unit Battery Fire Japan Airlines Boeing 787-8, JA829J, Boston, Massachusetts January , 2013, National Transportation Safety Board.

Thermal characteristics of lithium ion secondary cells in high temperature environments using an accelerating rate calorimeter

The analysis of the thermal behavior of Li-ion secondary cells in high temperature environments is one of the most important issues for the application of these batteries in electric vehicles. In this study, by using an accelerating rate calorimeter (ARC), we monitored the exothermic and thermal runaway behaviors of two lithium ion secondary cells using different cathode materials, lithium cobalt oxide (LCO) and lithium manganese oxide (LMO). Also, the internal resistance and open circuit voltage of the cells were recorded. As a result of the thermal runaway tests, it was found that the amount of heat released from the cell using LMO as the cathode material was lower when compared to the cell using LCO. In general, LMO exhibits a high thermal stability. This is mainly due to differences between the cathode materials. In addition, a sudden increase in the internal resistance and decrease in the open circuit voltage of the cells were detected, which seemed to be due to the shutting down of the cell separators. As already described, by combining the ARC tests and electrochemical measurements, we were able to identify the thermal and electrochemical characteristics, including the thermal runaway, based on the materials used in the Li-ion secondary cells.

Venting Design for Di-tert-butyl Peroxide Runaway Reaction Based on Accelerating Rate Calorimeter Test

In order to design the relief system size of di-tert-butyl peroxide (DTBP) storage tanks, the runaway reaction of DTBP was simulated by accelerating rate calorimeter (ARC). The results indicated that under adiabatic conditions the initial exothermic temperature was 102.6°C, the maximum self-heating rate was 3.095×107°C·min−1, the maximum self-heating temperature was 375.9°C, and the pressure produced by unit mass was 4.512 MPa·g−1. Judged by ARC test, the emergency relief system for DTBP was a hybrid system. Based on Design Institute for Emergency Relief System (DIERS) method, the releasing mass flow rate W was determined by Leung methods, and the mass velocity G was calculated by two modified Omega methods. The two relief sizes calculated by monograph Omega method and arithmetic Omega method are close, with only 0.63% relative error. The monograph Omega method is more convenient to apply.

空気圧入法適用性に関する評価スタディ

Recently, High Pressure Air Injection (HPAI) is considered to be an effective EOR method to light oil reservoirs. HPAI has some remarkable merits as follows. (1) Injection gas source is air, which can be supplied anywhere. (2) Initial and operation costs are inexpensive because the main facility required is only air compressor and air is free. (3) Air can be applied even in low permeable reservoirs where water cannot be injected. However, it is pointed out that the evaluation method for HPAI is difficult, because oxidation and combustion reactions are complicated. A Japanese domestic oil field has been investigated to apply HPAI since 1999.A series of experiments is essential in HPAI study. Accelerating Rate Calorimeter (ARC) test and Combustion Tube (CT) test are generally conducted to evaluate a potential of air injection in fields. ARC test is used to determine the extent and continuity of reactions in the low and high temperature range. The purposes of the CT test are (1) to assess the overall burning characteristics of oil, (2) to measure incremental oil production, air and fuel requirements and other parameters and (3) to measure produced gas compositions and oil and water production to provide benchmarks for monitoring future field operations.The results of ARC tests suggest that the ignition temperature of the oil may be higher than the reservoir temperature. It means an artificial ignition method should be conducted for HPAI in the field. Additional ARC tests were carried out to assess the influence of oxygen slug, NO2 addition and linseed oil on ignition temperature as the ignition method. The experimental results suggest that the linseed oil method is the most promising, because the ignition temperature with high concentration of linseed oil is below the reservoir temperature. Two CT tests were also conducted, in low water saturation case and high water saturation case after waterflooding, to estimate applicability of HPAI including on tertiary mode. Both tests show stable combustion performance in terms of temperature, pressure response, produced gas compositions and incremental oil production.On the other hand, numerical simulation is important to predict field production performance. The appropriate reaction kinetics on the combustion has to be used in the numerical simulation. History matching with CT tests was conducted to obtain the kinetics. Two kinds of reactions, “oxidation reaction” and “combustion reaction” were used in the study. In the former reaction, oxygen is consumed by the oil to form oxidation compounds. In the latter one, oxygen reacts with the compounds to form carbon dioxide and water. Reaction parameters were used as matching parameters. Good results of history matching with both CT tests using same reaction kinetics were obtained.

Laboratory Screening for Air Injection-Based IOR in Two Waterf looded Light Oil Reservoirs

Abstract In the last two decades, air injection has proven to be an effective method for enhanced recovery from light oil reservoirs. This has led to a need for effective laboratory procedures for screening potential candidate reservoirs, many of which have been previously waterflooded. Experiments at the University of Calgary have shown the benefit of Accelerating Rate Calorimeter (ARC) tests in conjunction with traditional combustion tube testing at reservoir pressure for the planning of field scale implementations. In this study, four ARC tests and two combustion tube tests were performed on resaturated cores from each of the Avil? and Troncoso waterflooded light oil reservoirs of Argentina. The paper reviews the characteristics of the two reservoirs, describes the tests that were performed on the reservoir samples, and summarizes the results obtained. The ARC tests provided Arrhenius-type kinetic rate data for the ignition and combustion reactions. The combustion tube tests were used to evaluate the air requirements and overall burn stability. For each reservoir, one combustion tube test was performed at the original oil and water saturation while the second test was performed at the waterflooded saturation. The effect of initial oil saturation on the burning characteristics and liquid recoveries is of particular interests to operators considering air injection-based oil recovery projects. Background The application of air injection-based processes (or fireflooding) to deep, high pressure light oil reservoirs is a relatively new IOR process. While past applications of this process to low API oils have met with mixed success, many of the problems encountered in heavy oil reservoirs relating to mobility and unfavourable oxidation characteristics are not an issue in high API oils(1, 2, 3). The success of this process is evident from the recent start-up of a new project by Continental Resources, injecting 85 MMscfd of air into a field in the Williston Basin. Currently, several other companies are actively researching potential candidate reservoirs for air injection- based recovery processes. While air injection into light oil reservoirs is not a new process, more recent applications of air injection to light oil fields have targeted reserves that are deep and/or have had low permeability, rendering them poor candidates for waterflooding(4). However, the resulting successes and potential process benefits(5) have extended interest in this IOR process to all types of light oil reservoirs, including those that have undergone waterflooding as a secondary recovery mechanism. Air injection into previously waterflooded reservoirs entails additional considerations. From an operational viewpoint, extensive waterflooding can result in the lowering of the overall reservoir temperature, making the oil less reactive to the oxygen in the injected air. Air injection processes rely on combustion reactions between oxygen and a fraction of the oil in place to produce heat and carbon oxides, so it may be necessary to provide an artificial ignition source. The presence of large saturations of water in the reservoir constitutes a heat load to the combustion process, as it is vapourized by the advancing reaction front. Highly permeable flow channels may have very low residual oil saturations, particularly around water injection wells.

Screening of Three Light-Oil Reservoirs for Application of Air Injection Process by Accelerating Rate Calorimetric and TG/PDSC Tests

Abstract A series of Accelerating Rate Calorimeter (ARC) and Thermo Gravimetric Pressurized Differential Scanning Calorimeter (TG/PDSC) tests was conducted on oil-rock systems from three light-oil reservoirs (Oils A, B and C) to screen and evaluate the potential of the air injection process. ARC tests helped determine, a priori, whether the test oils would autoignite under reservoir conditions of pressure and temperature. Also, the limits of the low temperature range were established and Arrhenius oxidation kinetics parameters were estimated. The goals of the TG/PDSC tests were to identify temperature ranges over which the oil reacted with oxygen in the injected air, and to determine the fraction of the sample responsible for the reactivity. ARC and TG/PDSC tests demonstrate that Oils A and C offer favourable exothermic behaviour in the low temperature range with lower activation energies and low orders of reactions?the conditions typically favouring autoignition. The presence of rock material lowered the ignition temperature, confirming its impact on O2 uptake. Oil A had a lower energy generation (ignition) temperature, and a stronger and smoother transition to the higher temperature region. Both oils responded favourably during isothermal aging with air as manifested by a drop in the initial self-heating temperature (a 15 °C drop for Oil A and a 10 °C drop for Oil C). The third oil, Oil B, showed unusual characteristics, with almost no impact of the core material on the starting temperature of the exotherm; rather, the core material appeared to have acted as a heat sink. Overall, Oil B needed a much higher activation energy to ignite, and its order of reactions was very high. Furthermore, it showed no response to isothermal aging, and hence, it is less likely to autoignite in the reservoir. esults revealed that ARC and TG/PDSC tests could be an effective tool to rank and study the oxidation characteristics in the low temperature range of the candidate oils. Also, it was observed that the oil composition and rock mineralogy are important factors affecting the type and rate of the oxidation reactions occurring in the low temperature range. Introduction The air injection process is now a proven and viable process in improving oil recovery from several light-oil reservoirs. As a result, it has generated much interest in recent years(1–5). Cheap and abundant, air is also touted as a possible alternative to highcost hydrocarbon and CO2 gases in certain circumstances or locations where water is scarce(6–10). Moore et al(11) suggest that in an air injection process in lightoil reservoirs, both oxygen addition and bond scission reactions take place. Oxygen addition reactions are believed to occur at temperatures between 100 °C and 150 °C. These reactions are characterized by heavier oxygenated hydrocarbon products. Bond scission reactions for light oils typically occur at temperatures in the 150 to 300 °C and the 350 to 700 °C range. These reactions produce carbon oxides, water (steam) and heat, which contribute significantly towards mobilizing oil.