scholarly journals Numerical Simulation of In Situ Combustion of Oil Shale

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Huan Zheng ◽  
Weiping Shi ◽  
Dali Ding ◽  
Chuangye Zhang
Keyword(s):  
Oxygen Content ◽  
Oil Shale ◽  
Volume Fraction ◽  
Gas Injection ◽  
Injection Rate ◽  
Oxidation Reactions ◽  
Arrhenius Law ◽  
In Situ Combustion ◽  
Conservation Equations

This paper analyzes the process of in situ combustion of oil shale, taking into account the transport and chemical reaction of various components in porous reservoirs. The physical model is presented, including the mass and energy conservation equations and Darcy’s law. The oxidation reactions of oil shale combustion are expressed by adding source terms in the conservation equations. The reaction rate of oxidation satisfies the Arrhenius law. A numerical method is established for calculating in situ combustion, which is simulated numerically, and the results are compared with the available experiment. The profiles of temperature and volume fraction of a few components are presented. The temperature contours show the temperature variation in the combustion tube. It is found that as combustion reaction occurs in the tube, the concentration of oxygen decreases rapidly, while the concentration of carbon dioxide and carbon monoxide increases contrarily. Besides, the combustion front velocity is consistent with the experimental value. Effects of gas injection rate, permeability of the reservoir, initial oil content, and injected oxygen content on the ISC process were investigated in this study. Varying gas injection rate and oxygen content is important in the field test of ISC.

Application and Exploration of Early In-Situ Combustion Huff-and-Puff Technology in a Deep Undisturbed Reservoir with Extra Heavy Oil

2021 ◽  
pp. 1-13
Author(s):  
Wang Xiaoyan ◽  
Zhao Jian ◽  
Yin Qingguo ◽  
Cao Bao ◽  
Zhang Yang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Heavy Oil ◽  
Gas Injection ◽  
Thermal Recovery ◽  
Oil Field ◽  
Pilot Test ◽  
In Situ Combustion ◽  
Coiled Tubing

Summary Achieving effective results using conventional thermal recovery technology is challenging in the deep undisturbed reservoir with extra-heavy oil in the LKQ oil field. Therefore, in this study, a novel approach based on in-situ combustion huff-and-puff technology is proposed. Through physical and numerical simulations of the reservoir, the oil recovery mechanism and key injection and production parameters of early-stage ultraheavy oil were investigated, and a series of key engineering supporting technologies were developed that were confirmed to be feasible via a pilot test. The results revealed that the ultraheavy oil in the LKQ oil field could achieve oxidation combustion under a high ignition temperature of greater than 450°C, where in-situ cracking and upgrading could occur, leading to greatly decreased viscosity of ultraheavy oil and significantly improved mobility. Moreover, it could achieve higher extra-heavy-oil production combined with the energy supplement of flue gas injection. The reasonable cycles of in-situ combustion huff and puff were five cycles, with the first cycle of gas injection of 300 000 m3 and the gas injection volume per cycle increasing in turn. It was predicted that the incremental oil production of a single well would be 500 t in one cycle. In addition, the supporting technologies were developed, such as a coiled-tubing electric ignition system, an integrated temperature and pressure monitoring system in coiled tubing, anticorrosion cementing and completion technology with high-temperature and high-pressure thermal recovery, and anticorrosion injection-production integrated lifting technology. The proposed method was applied to a pilot test in the YS3 well in the LKQ oil field. The high-pressure ignition was achieved in the 2200-m-deep well using the coiled-tubing electric igniter. The maximum temperature tolerance of the integrated monitoring system in coiled tubing reached up to 1200°C, which provided the functions of distributed temperature and multipoint pressure measurement in the entire wellbore. The combination of 13Cr-P110 casing and titanium alloy tubing effectively reduced the high-temperature and high-pressure oxygen corrosion of the wellbore. The successful field test of the comprehensive supporting engineering technologies presents a new approach for effective production in deep extra-heavy-oil reservoirs.

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.

A Feasibility Study of an In Situ Retorting Process for Oil Shale

1968 ◽  
Vol 8 (03) ◽  
pp. 231-240 ◽  
Author(s):  
Allen L. Barnes ◽  
Allen M. Rowe
Keyword(s):  
Heat Transfer ◽  
Oil Shale ◽  
Gas Injection ◽  
Thermal Capacity ◽  
Order Partial Differential Equation ◽  
Conduction Heat Transfer ◽  
Hot Gas ◽  
Transfer Study ◽  
Vertical Fractures

Abstract A heat transfer study was made of hot gas injection into oil shale through wells interconnected by vertical fractures. This analysis involved the simultaneous numerical solution of a nonlinear, second-order partial differential equation that describes two-dimensional conduction heat transfer in oil shale and a non linear first-order partial differential equation that describes convection heat transfer in the fractures. Three nonlinear, temperature-dependent coefficients were used in this work; they are thermal conductivity, thermal capacity and retorting endothermic heat losses of oil shale. Vertical fractures were considered to be of finite height. Although vertical conduction heat transfer was not considered, an estimate of the error resulting from this limitation was made. How retorting efficiency was affected by injected gas temperature, injection rate, system geometry, cyclic injection and time were investigated. Results from this study show that the rate of retorting oil shale is a direct function of both injection temperature and rate, and the theoretical producing air-oil ratio:(AOR) is an inverse function of temperature. Retorting rates are constant until "breakthrough" of the 700 F isotherm at the producing. well, assuming constant injection parameters. Retorting rates for bounded systems are higher than the analogous unbounded systems and likewise AOR's are less. The use of an alternating injection-soak routine with high injection rates is less efficient than continuous injection at lower rates. These results indicate that injection temperatures on the order of 2000 F or greater may give theoretical AOR's in the economic range. Introduction Over half of the known oil shale reserves are located in the U.S., and most of them lie in the Piceance Creek basin of Western Colorado. The Colorado oil shale outcrops on the edges of the Piceance Greek Basin. At the outcrops the shale beds are relatively thin, from 25 to 50 ft thick. In the center of the basin the oil shale is as great as 2,000 ft thick and is covered with 1,000 ft of overburden. It has been estimated that there are over 1,000 billion bbl of oil in shales having an oil content over 15 gal/ton in this basin. Oil shale does not contain free oil but an organic matter called kerogen. Kerogen yields petroleum hydrocarbons by destructive distillation. It must be heated to approximately 700 F, at which temperature it decomposes into shale oil, gases and coke. The U.S. Bureau of Mines and, more recently, oil companies have conducted considerable research on surface retorting methods to economically recover oil from this shale. Another approach to exploit the oil shale deposits, in particular that portion having 1,000 ft of overburden, is to retort the oil shale in place and produce the liquid and gaseous hydrocarbons through wells drilled into the shale. Some research has been done on this approach. There are several variations to the in situ retorting approach. These variations fall into one of two groups, depending upon the geometry of the system:retorting in a highly fractured or broken up matrix;retorting from single fractures between production and injection wells. The latter is the group studied. Several investigators, using various assumptions, have studied flow of heat through horizontal systems. The objective of this work was to make a heat transfer study of in situ retorting oil shale by hot gas injection through wells interconnected by single vertical fractures of finite height. The oil shale thermal conductivity, thermal capacity and retorting endothermic heat losses were considered to be functions of temperature. SPEJ P. 231ˆ

scholarly journals Simulation Study of Allied In-Situ Injection and Production for Enhancing Shale Oil Recovery and CO2 Emission Control

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3961
Author(s):  
Haiyang Yu ◽  
Songchao Qi ◽  
Zhewei Chen ◽  
Shiqing Cheng ◽  
Qichao Xie ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Co2 Emission ◽  
Gas Injection ◽  
Water Injection ◽  
Oil Production ◽  
Injection Rate ◽  
Oil Reservoirs ◽  
Shale Oil ◽  
Shale Oil Reservoirs

The global greenhouse effect makes carbon dioxide (CO2) emission reduction an important task for the world, however, CO2 can be used as injected fluid to develop shale oil reservoirs. Conventional water injection and gas injection methods cannot achieve desired development results for shale oil reservoirs. Poor injection capacity exists in water injection development, while the time of gas breakthrough is early and gas channeling is serious for gas injection development. These problems will lead to insufficient formation energy supplement, rapid energy depletion, and low ultimate recovery. Gas injection huff and puff (huff-n-puff), as another improved method, is applied to develop shale oil reservoirs. However, the shortcomings of huff-n-puff are the low sweep efficiency and poor performance for the late development of oilfields. Therefore, this paper adopts firstly the method of Allied In-Situ Injection and Production (AIIP) combined with CO2 huff-n-puff to develop shale oil reservoirs. Based on the data of Shengli Oilfield, a dual-porosity and dual-permeability model in reservoir-scale is established. Compared with traditional CO2 huff-n-puff and depletion method, the cumulative oil production of AIIP combined with CO2 huff-n-puff increases by 13,077 and 17,450 m3 respectively, indicating that this method has a good application prospect. Sensitivity analyses are further conducted, including injection volume, injection rate, soaking time, fracture half-length, and fracture spacing. The results indicate that injection volume, not injection rate, is the important factor affecting the performance. With the increment of fracture half-length and the decrement of fracture spacing, the cumulative oil production of the single well increases, but the incremental rate slows down gradually. With the increment of soaking time, cumulative oil production increases first and then decreases. These parameters have a relatively suitable value, which makes the performance better. This new method can not only enhance shale oil recovery, but also can be used for CO2 emission control.

scholarly journals Study of the Radical Chain Mechanism of Hydrocarbon Oxidation for In Situ Combustion Process

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Alexandra Ushakova ◽  
Vladislav Zatsepin ◽  
Mikhail Varfolomeev ◽  
Dmitry Emelyanov
Keyword(s):  
Heat Release ◽  
Oil Recovery ◽  
Combustion Process ◽  
Chain Process ◽  
Oxidation Reactions ◽  
Scanning Calorimetry ◽  
Radical Chain ◽  
Initial Oxidation ◽  
In Situ Combustion

Despite the abundance of in situ combustion models of oil oxidation, many of the effects are still beyond consideration. For example, until now, initial stages of oxidation were not considered from a position of radical chain process. This is a serious difficulty for the simulation of oil recovery process that involves air injection. To investigate the initial stages of oxidation, the paper considers the sequence of chemical reactions, including intermediate short-living compounds and radicals. We have attempted to correlate the main stages of the reaction with areas of heat release observed in the experiments. The system of differential equations based on the equations of oxidation reactions was solved. Time dependence of peroxides formation and start of heat release is analytically derived for the initial stages. We have considered the inhibition of initial oxidation stages by aromatic oil compounds and have studied the induction time in dependence on temperature. Chain ignition criteria for paraffins and crude oil in presence of core samples were obtained. The calculation results are compared with the stages of oxidation that arise by high-pressure differential scanning calorimetry. According to experimental observations we have determined which reactions are important for the process and which can be omitted or combined into one as insignificant.

A Laboratory-Scale Experimental Study of In-Situ Combustion Processes

1994 ◽  
Vol 116 (3) ◽  
pp. 169-174 ◽  
Author(s):  
M. Hubbard ◽  
D. K. Krehbiel ◽  
S. R. Gollahalli
Keyword(s):  
Experimental Study ◽  
Injection Rate ◽  
Laboratory Scale ◽  
Air Injection ◽  
Measured Temperature ◽  
Oil Sand ◽  
In Situ Combustion ◽  
Oil Saturation ◽  
Liquid Yield

A laboratory-scale experimental study of in-situ combustion for enhanced oil recovery is presented. The effects of oil saturation, preheating of the oil-sand bed, porosity of sand, and air-injection rate on both the time history of liquid yield and the total liquid yield have been determined. From the measured temperature profiles and charred length of oil-sand bed, the propagation rate of combustion front has been deduced. The volumetric concentrations of CO2 and O2 in the effluent gas have been measured. The rate of liquid yield is highest in the initial periods of insitu heating or combustion. Air-injection rate, although it has an indirect influence on the temperatures achieved in the bed, exerts only a weak effect on the liquid yield. The increase in porosity of sand increases the liquid yield rate. The relative effects of air injection rate, oil saturation, and the porosity of sand under combustion conditions are simulated well by preheating the bed.

Chemical Aspects of In-Situ Combustion - Heat of Combustion and Kinetics

1972 ◽  
Vol 12 (05) ◽  
pp. 410-422 ◽  
Author(s):  
J.G. Burger
Keyword(s):  
Porous Media ◽  
Combustion Front ◽  
Combustion Process ◽  
Heat Of Combustion ◽  
Oxidation Reactions ◽  
In Situ Combustion ◽  
Oxidation Of Hydrocarbons ◽  
Kinetics Of ◽  
Heat Released

Abstract General remarks on the oxidation reactions of hydrocarbons involved in in-situ combustion are followed by estimates of heat releases. A formula is derived for computing the heat of combustion in the high-temperature zone. Reaction kinetics in porous media applied to the in-situ combustion porous media applied to the in-situ combustion process is discussed. It is observed that there is process is discussed. It is observed that there is some similarity between the kinetics of reverse and partially quenched combustion processes. The influence of additives on crude oil oxidation in porous media is illustrated by effluent gas analysis experiments. Some information concerning the values of the kinetic parameters of the reaction controlling the velocity of a reverse combustion front is derived from the interpretation of laboratory experiments, using a numerical model. Introduction A great deal of laboratory and field work has been done on thermal recovery methods. The importance and limitations of these techniques have been extensively studied. However, some of the chemical and physical problems involved that needed to be elucidated were studied as part of a research program carried out by the Institut Francais du Petrole. Specific problems are created by in-situ combustion since both the possibility of combustion-front propagation and the air requirement are controlled by the extent of the exothermic oxidation reactions. Actually, the propagation velocity of a forward combustion front depends on the fuel formation and combustion, which are controlled by the kinetics of these processes; furthermore, the peak temperature is related to the heat released by oxidation and combustion reactions. Therefore, a quantitative estimation of the parameters related to the chemical aspects of the parameters related to the chemical aspects of the process is a necessary step in studying combustion process is a necessary step in studying combustion through a porous medium. General and theoretical considerations on heats of reaction and kinetics are presented and illustrated by experimental data and numerical interpretation of the results. HEAT RELEASED IN THE OXIDATION OF HYDROCARBONS DESCRIPTION OF OXIDATION REACTIONS A great number of reaction products are produced by the oxidation of hydrocarbons. By taking into account the formation of bonds between one carbon atom and oxygen, it is possible to derive the most important processes. Complete combustion, (1) 2 2 2 2H H3R C R  +  ---- O  → RR  +  CO + H O Incomplete combustion, (2) 2 2H H R C R  +  O  → RR  +  CO  +  H O Oxidation to carboxylic acid, (3) 2 2 2H OH H3 OR C H  +  --- O  → R - C  +  H O Oxidation to aldehyde, (4) H H R C Oxidation to ketone, (5) 2 2H O H R C R '  +  O  → R - C - R;  +  H O Oxidation to alcohol, (6) R' R; R C H SPEJ p. 410

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