In-situ Combustion for Oil and Gas
Hi everyone,
My company is considering to get a TOUGH license and wondering if it is suitable for our project.
I am wondering if we can use it for in-situ combustion for oil and gas extraction. I have been looking at User's Guides and example problems. I am still not quite sure if it is the right one.
I found that there is EOS8 that is compatible for Water, air, oil, and heat. However, the case also needs the capability to simulate combustion which I am not sure the TOUGH2/TOUGH3 with EOS8 will be enough for that. It seems that TOUGHREACT is capable of doing the combustion or oxidation but it doesn't have the EOS for oil. Which one is the right one to get and if there is no TOUGH version that capable of doing that, is getting the source code and improving it will be possible?
Regards,
Ilham Permata
1 reply
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Dear Ilham,
from the Oil field glossary by Schlumberger: "In-situ combustion - A method of thermal recovery in which fire is generated inside the reservoir by injecting a gas containing oxygen, such as air. A special heater in the well ignites the oil in the reservoir and starts a fire. The heat generated by burning the heavy hydrocarbons in place produces hydrocarbon cracking, vaporization of light hydrocarbons and reservoir water in addition to the deposition of heavier hydrocarbons known as coke. "
Thus, to model in-situ combustion a complex compositional 3-phase flow approach for real mixtures of water and hydrocarbons at high temperature (above 500°C) is necessary.
EOS8 uses a simple 'dead-oil' approach in which there are only 3 mass components: water, a volatile component and a non-volatile component. Max T is 350°C (as for standard TOUGH2/TOUGH3 EOS modules) and there are of course no oxidation reactions involved, nor injected oxygen and N2 nor CO2 generated by the combustion can be modeled. Modify TOUGH2-EOS8 for in-situ combustion does not seem feasible.
A 3-phase compositional approach for water, hydrocarbons and NCG mixtures is implemented in TMVOC (Pruess and Battistelli, 2002), but its EOS has been developed for near surface applications related to the contamination of the subsurface by organic contaminants. The EOS is not suitable for high P nor for T above the critical point of each hydrocarbon simulated.
TMVOCBio (Battistelli, 2004; 2008; Jung and Battistelli, 2017) implements biodegradation reactions within TMVOC under iTOUGH2, potentially allowing to simulate oxidation reactions of the hydrocarbons. The presently implemented Monod kinetics could be probably modified to simulate combustion processes and, may be, the cracking reactions of heavier HCs, but would not be able to simulate the deposition of heavier HC (coke).
The cubic EOS implemented in TMVOCBio is the same EOS implemented in TMVOC, not able to simulate real hydrocarbons mixtures at high P and T.
I think TOUGHREACT is also not able to simulate in-situ combustion, because of the need of an appropriate EOS coupled to it (which does not exist) and again because of T limitations.
Probably the TOUGH2 code closer to your needs would be TOGA (TOGA: A TOUGH code for modeling three-phase, multi-component, and non-isothermal processes involved in CO2-based Enhanced Oil Recovery, by Pan and Oldenburg, LBNL-1006472), but I do not know if the code is available outside LBNL. It would be any way necessary to include the capability to simulate oxidation and cracking reactions, as well as increase the T above 500°C, which would require supercritical water capabilities such those implemented in EOS1sc.
Regards,
Alfredo