scholarly journals Numerical Validation of Analytical Estimates for Propagation of Thermal Waves Generated by Gas-Solid Combustion

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-18
Author(s):  
Weslley da Silva Pereira ◽  
Grigori Chapiro

Gas-solid combustion appears in many applications such as in situ combustion, which is a potential technique for oil recovery. Previous work has analyzed traveling wave solutions and obtained analytical formulas describing combustion wave temperature, velocity, and gas velocity for one-dimensional gas-solid combustion model using geometrical singular perturbation theory. In the present work these formulas are generalized. Using numerical simulation we show that they can be adapted and then applied to describe more general two-dimensional models for in situ combustion in a nonhomogeneous porous medium.

SPE Journal ◽  
2013 ◽  
Vol 18 (06) ◽  
pp. 1217-1228 ◽  
Author(s):  
Hascakir Berna ◽  
Cynthia M. Ross ◽  
Louis M. Castanier ◽  
Anthony R. Kovscek

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.


2021 ◽  
pp. 1-13
Author(s):  
Melek Deniz Paker ◽  
Murat Cinar

Abstract A significant portion of world oil reserves reside in naturally fractured reservoirs and a considerable amount of these resources includes heavy oil and bitumen. Thermal enhanced oil recovery methods (EOR) are mostly applied in heavy oil reservoirs to improve oil recovery. In situ combustion (/SC) is one of the thermal EOR methods that could be applicable in a variety of reservoirs. Unlike steam, heat is generated in situ due to the injection of air or oxygen enriched air into a reservoir. Energy is provided by multi-step reactions between oxygen and the fuel at particular temperatures underground. This method upgrades the oil in situ while the heaviest fraction of the oil is burned during the process. The application of /SC in fractured reservoirs is challenging since the injected air would flow through the fracture and a small portion of oil in the/near fracture would react with the injected air. Only a few researchers have studied /SC in fractured or high permeability contrast systems experimentally. For in situ combustion to be applied in fractured systems in an efficient way, the underlying mechanism needs to be understood. In this study, the major focus is permeability variation that is the most prominent feature of fractured systems. The effect of orientation and width of the region with higher permeability on the sustainability of front propagation are studied. The contrast in permeability was experimentally simulated with sand of different particle size. These higher permeability regions are analogous to fractures within a naturally fractured rock. Several /SC tests with sand-pack were carried out to obtain a better understanding of the effect of horizontal vertical, and combined (both vertical and horizontal) orientation of the high permeability region with respect to airflow to investigate the conditions that are required for a self-sustained front propagation and to understand the fundamental behavior. Within the experimental conditions of the study, the test results showed that combustion front propagated faster in the higher permeability region. In addition, horizontal orientation almost had no effect on the sustainability of the front; however, it affected oxygen consumption, temperature, and velocity of the front. On the contrary, the vertical orientation of the higher permeability region had a profound effect on the sustainability of the combustion front. The combustion behavior was poorer for the tests with vertical orientation, yet the produced oil AP/ gravity was higher. Based on the experimental results a mechanism has been proposed to explain the behavior of combustion front in systems with high permeability contrast.


1981 ◽  
Vol 103 (4) ◽  
pp. 296-300
Author(s):  
S. M. Farouq Ali ◽  
J. Ferrer

Thermal recovery models for oil recovery consist of steam injection and in-situ combustion simulators. At the present time, steam injection simulators have been developed to a point where it is possible to reliably simulate portions of a fieldwide flood. Cyclic steam stimulation simulation still entails a number of questionable assumptions. Formation parting cannot be simulated in either case. In-situ combustion simulators lack the capability for front tracking. Even though the models are rather sophisticated, process mechanism description and input data are inadequate.


Fuel ◽  
2021 ◽  
Vol 285 ◽  
pp. 119216
Author(s):  
Seyedsaeed Mehrabi-Kalajahi ◽  
Mikhail A. Varfolomeev ◽  
Chengdong Yuan ◽  
Almaz L. Zinnatullin ◽  
Nikolay O. Rodionov ◽  
...  

1980 ◽  
Vol 20 (06) ◽  
pp. 533-554 ◽  
Author(s):  
Keith H. Coats

Abstract This paper describes a numerical model forsimulating wet or dry, forward or reverse combustionin one, two, or three dimensions. The formulation isconsiderably more general than any reported to date.The model allows any number and identities ofcomponents. Any component may be distributed inany or all of the four phases (water, oil, gas, andsolid or coke.The formulation allows any number of chemicalreactions. Any reaction may have any number ofreactants, products, and stoichiometry, identifiedthrough input data. The energy balance accounts forheat loss and conduction, conversion, and radiationwithin the reservoir.The model uses no assumptions regarding degreeof oxygen consumption. The oxygen concentration iscalculated throughout the reservoir in accordancewith the calculated fluid flow pattern and reactionkinetics. The model, therefore, simulates the effectsof oxygen bypassing caused by kinetic-limitedcombustion or conformance factors.We believe the implicit model formulation resultsin maximum efficiency (lowest computing cost), andrequired computing times are reported in the paper.The paper includes comparisons of model resultswith reported laboratory adiabatic-tube test results.In addition, the paper includes example field-scalecases, with a sensitivity study showing effects on oilrecovery of uncertainties in rock/fluid properties. Introduction Recent papers by Ali, Crookston et al., andYoungren provide a comprehensive review of earlierwork in numerical modeling of the in-situcombustion process.The trend in this modeling has been toward morerigorous treatment of the fluid flow and interphasemass transfer; inclusion of more components, morecomprehensive reaction kinetics, and stoichiometry;and more implicit treatment of the finite differencemodel equations.The purpose of this work was to extend thegenerality of previous models while preserving orreducing the associated computing-time requirement.The most comprehensive or sophisticated combustionmodels described to date appear to be thoseof Crookston et al. and Youngren. Therefore, wecompare our model formulation and results here withthose models.A common objective of different investigators'efforts in modeling in-situ combustion is developmentof more efficient formulations and methods ofsolution. This is especially important in thecombustion case because of the large number ofcomponents and equations involved. For a given numberof components and reactions, computing time pergrid block per time step will increase rapidly as theformulation is rendered more implicit. However, increasing implicitness tends to allow larger timesteps, which in turn reduces overall computingexpense. To pursue the above objective, then, authorsshould present as completely as possible the details oftheir formulations and the associatedcomputing-time requirements.The thermal model described here simulateswet or dry, forward or reverse combustion in one, two, or three dimensions. The formulation allowsany number and identities of components and anynumber of chemical reactions, with reactants, products, and stoichiometry specified through input products, and stoichiometry specified through input data. SPEJ P. 533


1958 ◽  
Vol 10 (08) ◽  
pp. 13-17 ◽  
Author(s):  
Joseph N. Breston

2013 ◽  
Vol 16 (02) ◽  
pp. 172-182 ◽  
Author(s):  
Anthony Kovscek ◽  
Louis M. Castanier ◽  
Margot Gerritsen

Author(s):  
Tatiana Danelon De Assis ◽  
Mariane Dos Santos Bispo ◽  
Jessica Yvonne Santa Cruz Cárdenas ◽  
Giulia Carvalho Fritis ◽  
Angel Enrique Ramírez Gutiérrez ◽  
...  

This work presents a mathematical model describing the in-situ combustion process, which can be used in enhanced oil recovery. The hyperbolic part of the system was solved as a Riemann Problem. Necessary conditions for the existence of a traveling wave solution were verified. Furthermore, theoretical results are verified by using numerical simulations.


Sign in / Sign up

Export Citation Format

Share Document