scholarly journals Use of two vertical injectors in place of a horizontal injector to improve the efficiency and stability of THAI in situ combustion process for producing heavy oils

2021 ◽  
Author(s):  
Muhammad Rabiu Ado
Keyword(s):  
Oil Recovery ◽  
Combustion Front ◽  
Combustion Process ◽  
Oil Production ◽  
Steam Injection ◽  
Electrical Heating ◽  
Heavy Oils ◽  
In Situ Combustion ◽  
Start Up

AbstractThe current commercial technologies used to produce heavy oils and bitumen are carbon-, energy-, and wastewater-intensive. These make them to be out of line with the global efforts of decarbonisation. Alternative processes such as the toe-to-heel air injection (THAI) that works as an in situ combustion process that uses horizontal producer well to recover partially upgraded oil from heavy oils and bitumen reservoirs are needed. However, THAI is yet to be technically and economically well proven despite pilot and semi-commercial operations. Some studies concluded using field data that THAI is a low-oil-production-rate process. However, no study has thoroughly investigated the simultaneous effects of start-up methods and wells configuration on both the short and long terms stability, sustainability, and profitability of the process. Using THAI validated model, three models having a horizontal producer well arranged in staggered line drive with the injector wells are simulated using CMG STARS. Model A has two vertical injectors via which steam was used for pre-ignition heating, and models B and C each has a horizontal injector via which electrical heater and steam were respectively used for pre-ignition heating. It is found that during start-up, ultimately, steam injection instead of electrical heating should be used for the pre-ignition heating. Clearly, it is shown that model A has higher oil production rates after the increase in air flux and also has a higher cumulative oil recovery of 2350 cm3 which is greater than those of models B and C by 9.6% and 4.3% respectively. Thus, it can be concluded that for long-term projects, model A settings and wells configuration should be used. Although it is now discovered that the peak temperature cannot in all settings tell how healthy a combustion front is, it has revealed that model A does indeed have far more stable, safer, and efficient combustion front burning quality and propagation due to the maintenance of very high peak temperatures of mostly greater than 600 °C and very low concentrations of produced oxygen of lower than 0.4 mol% compared to up to 2.75 mol% in model C and 1 mol% in model B. Conclusively, since drilling of, and achieving uniform air distribution in horizontal injector (HI) well in actual field reservoir are costly and impracticable at the moment, and that electrical heating will require unphysically long time before mobilised fluids reach the HP well as heat transfer is mainly by conduction, these findings have shown decisively that the easy-and-cheaper-to-drill two vertical injector wells configured in a staggered line drive pattern with the horizontal producer should be used, and steam is thus to be used for pre-ignition heating.

How the In-Situ Combustion Process Works in a Fractured System: 2D Core- and Block-Scale Simulation

2010 ◽  
Vol 13 (01) ◽  
pp. 118-130 ◽  
Author(s):  
H.. Fadaei ◽  
G.. Debenest ◽  
A.M.. M. Kamp ◽  
M.. Quintard ◽  
G.. Renard
Keyword(s):  
Oil Recovery ◽  
Combustion Process ◽  
Oil Production ◽  
Grid Size ◽  
Viscosity Reduction ◽  
Minor Effect ◽  
Fine Grid ◽  
In Situ Combustion ◽  
Matrix Block

Summary Simulation of an in-situ combustion (ISC) process was performed for a fractured system at core and matrix-block scales. The aim of this work was: (1) To predict the ISC extinction/propagation condition(s), (2) understand the mechanism of oil recovery, and (3) provide some guidelines for ISC upscaling for a fractured system. The study was based on a fine-grid, single-porosity, multiphase, and multicomponent simulation using a thermal reservoir simulator. First, the simulator was validated for 1D combustion using the corresponding analytical solutions. 2D combustion was validated using experimental results available in the literature. It was found that the grid size should not be larger than the combustion-zone thickness in order for the results to be independent of grid size. ISC in the fractured system was strongly dependent on the oxygen diffusion coefficient, while the matrix permeability played an important role in oil production. The effect of each production mechanism was studied separately whenever it was possible. Oil production is governed mainly by oil drainage because of gravity force, which is enhanced by viscosity reduction; possible pressure-gradient generation in the ISC process seems to have a minor effect. The nature (oil-production rate, saturations distribution, shape of the combustion front) of ISC at core scale was different from that in a single block with surrounding fracture. The important characteristics of different zones (i.e., combustion, coke, and oil zones) at block scale were studied, and some preliminary guidelines for upscaling are presented.

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.

An Experimental Investigation of In Situ Combustion in High Permeability Contrast Systems

2021 ◽  
pp. 1-13
Author(s):  
Melek Deniz Paker ◽  
Murat Cinar
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Combustion Front ◽  
Fractured Reservoirs ◽  
Front Propagation ◽  
High Permeability ◽  
Vertical Orientation ◽  
In Situ Combustion ◽  
Horizontal Orientation

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.

State-of-the-Art of Thermal Recovery Models

1981 ◽  
Vol 103 (4) ◽  
pp. 296-300
Author(s):  
S. M. Farouq Ali ◽  
J. Ferrer
Keyword(s):  
Oil Recovery ◽  
Input Data ◽  
State Of The Art ◽  
Front Tracking ◽  
Steam Injection ◽  
Thermal Recovery ◽  
In Situ Combustion ◽  
Cyclic Steam Stimulation ◽  
Recovery Models

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.

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.

Improving heavy oil oxidation performance by oil-dispersed CoFe2O4 nanoparticles in In-situ combustion process for enhanced oil recovery

Fuel ◽  
2021 ◽  
Vol 285 ◽  
pp. 119216
Author(s):  
Seyedsaeed Mehrabi-Kalajahi ◽  
Mikhail A. Varfolomeev ◽  
Chengdong Yuan ◽  
Almaz L. Zinnatullin ◽  
Nikolay O. Rodionov ◽  
...  
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Combustion Process ◽  
Oil Oxidation ◽  
Cofe2o4 Nanoparticles ◽  
In Situ Combustion ◽  
Oxidation Performance

scholarly journals TRAVELING WAVES FOR IN-SITU COMBUSTION IN POROUS MEDIA

2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Tatiana Danelon De Assis ◽  
Mariane Dos Santos Bispo ◽  
Jessica Yvonne Santa Cruz Cárdenas ◽  
Giulia Carvalho Fritis ◽  
Angel Enrique Ramírez Gutiérrez ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oil Recovery ◽  
Traveling Waves ◽  
Traveling Wave ◽  
Necessary Conditions ◽  
Combustion Process ◽  
Traveling Wave Solution ◽  
In Situ Combustion ◽  
Theoretical Results

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.

A New, Fast, and Efficient Method for Evaluating the Influence of Catalysts on In-Situ Combustion Process for Heavy Oil Recovery

2018 ◽  
Author(s):  
Kamil Sadikov ◽  
Chengdong Yuan ◽  
Seyed Saeed Mehrabi-Kalajahi ◽  
Mikhail A. Varfolomeev ◽  
Sarvardzhon A. Talipov
Keyword(s):  
Oil Recovery ◽  
Efficient Method ◽  
Heavy Oil ◽  
Combustion Process ◽  
Heavy Oil Recovery ◽  
In Situ Combustion

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.

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