scholarly journals Combustion tube experiments for in-situ combustion of relatively light crude oil and verification of numerical simulation model.

1999 ◽  
Vol 64 (3) ◽  
pp. 242-251
Author(s):  
Chengxie Hong ◽  
Atsushi Kishita ◽  
Takayuki Watanabe ◽  
Heiji Enomoto
Keyword(s):  
Numerical Simulation ◽  
Crude Oil ◽  
Simulation Model ◽  
Combustion Tube ◽  
In Situ Combustion ◽  
Light Crude Oil

Automation of an In-Situ Combustion Tube and Study of the Effect of Clay on the In-Situ Combustion Process

1982 ◽  
Vol 22 (04) ◽  
pp. 493-502 ◽  
Author(s):  
Shapour Vossoughi ◽  
G. Paul Willhite ◽  
William P. Kritikos ◽  
Ibrahim M. Guvenir ◽  
Youssef El Shoubary
Keyword(s):  
Thermal Analysis ◽  
Crude Oil ◽  
Combustion Process ◽  
Combustion Tube ◽  
Oxygen Utilization ◽  
Kaolinite Clay ◽  
In Situ Combustion ◽  
Adiabatic Conditions ◽  
Dsc Thermograms

Abstract A fully automated in-situ combustion apparatus supported by a minicomputer was designed, constructed, and tested.Results obtained from four adiabatic dry combustion runs to investigate the effect on clay on crude oil combustion are reported. Sand mixtures of varying clay (kaolinite) content were saturated with crude oil and water. The fourth run was performed with amorphous silica powder in the sand mixture for comparison with clay results.We concluded that the large surface area of the clays was a major contributor to the fuel deposition process. However, different oxygen utilization efficiencies obtained from both types of sand mixtures indicated that mechanisms controlling the combustion reaction also depended on the composition of the porous matrix.A thermogravimetric analyzer (TGA) and a differential scanning calorimeter (DSC) were used to obtain kinetic data on the effects of kaolinite type clay on crude oil combustion. The addition of kaolinite clay or silica powder changed the shape of the crude oil TGA/DSC thermograms significantly, but sand had no effect. The major effect on DSC thermograms was a shifting of the large amount of heat produced from a higher to lower temperature range. Reduction of activation energy caused by the addition of kaolinite clay to the crude oil indicates both catalytic and surface area effects on combustion/cracking reactions. Introduction In-situ combustion is a thermal recovery process in which a portion of the crude oil is coked and burned in situ to recover the remaining oil. Design of the process involves experimental evaluation of process variables in laboratory experiments. Variables sought experimentally for the design of the process are usually fuel availability, air requirement, oxygen utilization efficiency, combustion peak temperature, combustion front velocity, effect of porous matrix, and kinetic parameters. Four methods have been used to obtain design data for in-situ combustion projects. These include (1) adiabatic in-situ combustion tube runs, (2) isothermal reactors, (3) flood pot tests, and (4) thermal analysis techniques.This paper describes an investigation of the effect of clay on in-situ combustion involving results from adiabatic combustion tube runs and thermal analysis methods. Part 1 describes the minicomputer-based insitu combustion system developed as part of the research program. Part 2 demonstrates application of the system to study the effect of clays on the in-situ combustion process. Combustion tube runs described in Part 2 are supplemented with thermal analysis methods to evaluate the effect of clay on in-situ combustion of a Kansas crude oil. Part 1-Development of an Automated In-Situ Combustion Tube Adiabatic tube runs have been the most commonly used approach for studying in-situ combustion. Since heat loss is small to nil in thick reservoirs, in-situ combustion is assumed to occur under adiabatic conditions. Adiabatic conditions in tube runs can be achieved either by insulating the tube or by reducing the temperature gradient between the sandpack and the environment surrounding the tube, or both. To attain adiabatic conditions in a partially or noninsulated tube, the temperature of the surroundings must be raised to that of the sandpack as the combustion front moves along the tube. Heater bands with proportional heat loads controlled by individual controllers are used. This requires a large number of controllers to control the temperature of the outside SPEJ P. 493^

Predictability of Crude Oil In-Situ Combustion by the Isoconversional Kinetic Approach

SPE Journal ◽  
2011 ◽  
Vol 16 (03) ◽  
pp. 537-547 ◽  
Author(s):  
Murat Cinar ◽  
Berna Hasçakir ◽  
Louis M. Castanier ◽  
Anthony R. Kovscek
Keyword(s):  
Crude Oil ◽  
Combustion Front ◽  
Front Propagation ◽  
Combustion Tube ◽  
Complex Nature ◽  
Oil Viscosity ◽  
In Situ Combustion ◽  
Temperature Oxidation ◽  
Isoconversional Analysis

Summary One method to access unconventional heavy-crude-oil resources as well as residual oil after conventional recovery operations is to apply in-situ combustion (ISC) enhanced oil recovery. ISC oxidizes in place a small fraction of the hydrocarbon, thereby providing heat to reduce oil viscosity and increase reservoir pressure. Both effects serve to enhance recovery. The complex nature of petroleum as a multicomponent mixture and the multistep character of combustion reactions substantially complicate analysis of crude-oil oxidation and the identification of settings where ISC could be successful. In this study, isoconversional analysis of ramped temperature-oxidation (RTO) kinetic data was applied to eight different crude-oil samples. In addition, combustion-tube runs that explore ignition and combustion-front propagation were carried out. By using experimentally determined combustion kinetics of eight crude-oil samples along with combustion-tube results, we show that isoconversional analysis of RTO data is useful to predict combustion-front propagation. Isoconversional analysis also provides new insight into the nature of the reactions occurring during ISC. Additionally, five of the 10 crude-oil/rock systems studied employed a carbonate rock. No system displayed excessive oxygen consumption resulting from carbonate decomposition at combustion temperatures. This result is encouraging as it contributes to widening of the applicability of ISC.

Fuel Formation and Conversion During In-Situ Combustion of Crude Oil

SPE Journal ◽  
2013 ◽  
Vol 18 (06) ◽  
pp. 1217-1228 ◽  
Author(s):  
Hascakir Berna ◽  
Cynthia M. Ross ◽  
Louis M. Castanier ◽  
Anthony R. Kovscek
Keyword(s):  
Oil Recovery ◽  
Photoelectron Spectroscopy ◽  
Combustion Front ◽  
Combustion Products ◽  
Combustion Tube ◽  
Cross Sectional ◽  
In Situ Combustion ◽  
X Ray ◽  
Study Results

Summary In-situ combustion (ISC) is a successful method with great potential for thermal enhanced oil recovery. Field applications of ISC are limited, however, because the process is complex and not well-understood. A significant open question for ISC is the formation of coke or "fuel" in correct quantities that is sufficiently reactive to sustain combustion. We study ISC from a laboratory perspective in 1 m long combustion tubes that allow the monitoring of the progress of the combustion front by use of X-ray computed tomography (CT) and temperature profiles. Two crude oils—12°API (986 kg/m3) and 9°API (1007 kg/m3)—are studied. Cross-sectional images of oil movement and banking in situ are obtained through the appropriate analysis of the spatially and temporally varying CT numbers. Combustion-tube runs are quenched before front breakthrough at the production end, thereby permitting a post-mortem analysis of combustion products and, in particular, the fuel (coke and coke-like residues) just downstream of the combustion front. Fuel is analyzed with both scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). XPS and SEM results are used to identify the shape, texture, and elemental composition of fuel in the X-ray CT images. The SEM and XPS results aid efforts to differentiate among combustion-tube results with significant and negligible amounts of clay minerals. Initial results indicate that clays increase the surface area of fuel deposits formed, and this aids combustion. In addition, comparisons are made of coke-like residues formed during experiments under an inert nitrogen atmosphere and from in-situ combustion. Study results contribute to an improved mechanistic understanding of ISC, fuel formation, and the role of mineral substrates in either aiding or impeding combustion. CT imaging permits inference of the width and movement of the fuel zone in situ.

Kinetics of Wet In-Situ Combustion: A Review of Kinetic Models

2014 ◽  
Author(s):  
E. A. Cavanzo ◽  
S. F. Muñoz ◽  
A.. Ordoñez ◽  
H.. Bottia
Keyword(s):  
Kinetic Model ◽  
Crude Oil ◽  
Kinetic Models ◽  
Combustion Front ◽  
Chemical Interaction ◽  
Combustion Process ◽  
Oxidation Reactions ◽  
In Situ Combustion ◽  
Temperature Oxidation

Abstract In Situ Combustion is an enhanced oil recovery method which consists on injecting air to the reservoir, generating a series of oxidation reactions at different temperature ranges by chemical interaction between oil and oxygen, the high temperature oxidation reactions are highly exothermic; the oxygen reacts with a coke like material formed by thermal cracking, they are responsible of generating the heat necessary to sustain and propagate the combustion front, sweeping the heavy oil and upgrading it due to the high temperatures. Wet in situ combustion is variant of the process, in which water is injected simultaneously or alternated with air, taking advantage of its high heat capacity, so the steam can transport heat more efficiently forward the combustion front due to the latent heat of vaporization. A representative model of the in situ combustion process is constituted by a static model, a dynamic model and a kinetic model. The kinetic model represents the oxidative behavior and the compositional changes of the crude oil; it is integrated by the most representative reactions of the process and the corresponding kinetic parameters of each reaction. Frequently, the kinetic model for a dry combustion process has Low Temperature Oxidation reactions (LTO), thermal cracking reactions and the combustion reaction. For the case of wet combustion, additional aquathermolysis reactions take place. This article presents a full review of the kinetic models of the wet in situ combustion process taking into account aquathermolysis reactions. These are hydrogen addition reactions due to the chemical interaction between crude oil and steam. The mechanism begins with desulphurization reactions and subsequent decarboxylation reactions, which are responsible of carbon monoxide production, which reacts with steam producing carbon dioxide and hydrogen; this is the water and gas shift reaction. Finally, during hydrocracking and hydrodesulphurization reactions, hydrogen sulfide is generated and the crude oil is upgraded. An additional upgrading mechanism during the wet in situ combustion process can be explained by the aquathermolysis theory, also hydrogen sulphide and hydrogen production can be estimated by a suitable kinetic model that takes into account the most representative reactions involved during the combustion process.

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