Stability of In Situ Combustion Process to the Air Injection Stoppage

2012 ◽  
Author(s):  
Alexandru T. Turta
Keyword(s):  
Combustion Process ◽  
Air Injection ◽  
In Situ Combustion

scholarly journals Numerical Simulation Study of Heavy Oil Production by Using In-Situ Combustion

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 621 ◽  
Author(s):  
Yang ◽  
Han ◽  
Liu
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Bottom Water ◽  
Combustion Process ◽  
Air Injection ◽  
In Situ Combustion ◽  
Injection Speed ◽  
Heavy Oil Reservoirs ◽  
Injection Temperature

An in-situ combustion method is an effective method to enhance oil recovery with high economic recovery rate, low risk, fast promotion and application speed. Currently, in-situ combustion technique is regarded as the last feasible thermal recovery technology to replace steam injection in the exploitation of bitumen sands and heavy oil reservoirs. However, the oil-discharging mechanism during the in-situ combustion process is still not clearly understood. In this paper, the in-situ combustion process has been numerically simulated based on the Du 66 block. The effect of production parameters (huff and puff rounds, air injection speed, and air injection temperature) and geological parameters (bottom water thickness, stratigraphic layering, permeability ratio, and formation thickness) on the heavy oil recovery have been comprehensively analyzed. Results show that the flooding efficiency is positively correlated with the thickness of the bottom water, and negatively correlated with the formation heterogeneity. There exist optimum values for the oil layer thickness, huff and puff rounds, and air injection speed. And the effect of air injection temperature is not significant. The results of this paper can contribute to the understanding of mechanisms during in-situ combustion and the better production design for heavy oil reservoirs.

The Effect of Water Injection on Sustained Combustion in a Porous Medium

1970 ◽  
Vol 10 (02) ◽  
pp. 145-163 ◽  
Author(s):  
H.L. Beckers ◽  
G.J. Harmsen
Keyword(s):  
Cross Section ◽  
Combustion Zone ◽  
Water Injection ◽  
Combustion Process ◽  
Physical Reality ◽  
Porous Matrix ◽  
Theoretical Description ◽  
Air Injection ◽  
Injection Ratio

Abstract This paper gives a theoretical description of the various semisteady states that may develop if in an in-situ combustion process water is injected together with the air. The investigation bas been restricted to cases of one-dimensional flow without heat losses, such as would occur in a narrow, perfectly insulated tube. perfectly insulated tube. Different types of behavior can be distinguished for specific ranges of the water/air injection ratio. At low values of this ratio the injected water evaporates before it reaches the combustion zone, while at high values it passes through the combustion zone without being completely evaporated, but without extinguishing combustion. At intermediate values and at sufficiently high fuel in which all water entering the combustion zone evaporates before leaving it. Formulas are presented that give the combustion zone velocity as a function of water/air injection ratio for each of the possible situations. Introduction In-situ combustion of part of the oil in an oil-bearing formation has become an established thermal-recovery technique, even though its economic prospects are limited by inherent technical drawbacks. The process has been extensively investigated both in the laboratory and in the field, while theoretical studies have also been made. The latter studies showed how performance was affected by various physical and chemical phenomena, such as conduction and convection of phenomena, such as conduction and convection of heat, reaction rate and phase changes. The degree of simplification determined whether these studies were of an analytical or a numerical nature. Recently an improvement of the process has been proposed. This modification involves the proposed. This modification involves the injection of water together with the air. The water serves to recuperate the heat stored in the burned-out sand, which would otherwise be wasted. This heat is now used to evaporate water. The steam thus formed condenses downstream of the combustion zone, where it displaces oil. At sufficiently high water-injection rates unevaporated water is bound to enter the combustion zone because more heat is required for complete evaporation than is available in the hot sand. Experiments showed that even under these conditions combustion is maintained. The improvement consists in a lower oxygen consumption per barrel of oil displaced and lower combustion-zone temperatures. This paper gives a theoretical description of this so-called wet-combustion process as described by Dietz and Weijdema. The prime object is to answer the basic question whether at any water/air injection ratio this process can be steady so that combustion does not die out. This objective justifies a number of assumptions that do not entirely correspond to physical reality, but that owe necessary for a physical reality, but that owe necessary for a tractable analytical treatment. This treatment is limited to the following idealized conditions.The process occurs in a perfectly insulated cylinder of unit cross-sectional area and infinite length.The Hudds are homogeneously distributed over the cross-section of the cylinder.Exchange of heat between the fluid phases and between fluids and matrix is instantaneous, so that in any cross-section the fluid phases are in equilibrium and the temperatures of fluids and porous matrix are the same. porous matrix are the same.Pressure chops over distances of interest are small compared with the pressure itself. (Pressure is taken to be constant.)Injection rates are constant, and a steady state has already been obtained. The second assumption implies that no segregation of liquid and gas occurs. Experimentally this might be achieved by using small-diameter tubes, where segregation is largely compensated by capillarity. SPEJ P. 145

Interaction between aromatics and n-alkane for in-situ combustion process

2020 ◽  
Vol 187 ◽  
pp. 106770 ◽  
Author(s):  
Chengdong Yuan ◽  
Mikhail A. Varfolomeev ◽  
Artashes A. Khachatrian
Keyword(s):  
Combustion Process ◽  
In Situ Combustion
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