Increasing Injection Rate
I am currently working on a model where the reservoir permeability is only a few mD, but the injection rate is set at 3 kg/s. In the existing model, when the injection rate reaches 0.2 kg/s, the pressure approaches 600 bar, while the model runs normally at 0.1 kg/s. I would like to increase the injection rate but prefer not to change the reservoir permeability by orders of magnitude. Is it possible to achieve this using only TOUGH2-ECO2N? If so, what steps should I take? I have already tried refining the grid and adjusting lithology parameters. Are there any other approaches that might work?
I have attached a simplified input file for your reference. I would greatly appreciate it if you could take a look and provide any suggestions.
Thank you very much for your time and assistance!
Best regards
2 replies
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The injection rate must be physically meaningful. If the formation permeability/porosity remains the same, you have to increase the "mobility" of injection fluid to get higher injection rate. Fluid parameters such as viscosity, density, relative permeability may have an impact on mobility. If the reservoir has a higher temperature and/or higher gas saturation, it may allow slightly higher injection rate for a given pressure limitation.