An explicit finite difference model for prediction of wellbore pressure and temperature distribution in CO₂ geological sequestration

Abstract

To conveniently realize the coupling calculation between wellbore pressure and temperature and consider the friction loss in the process of wellbore flow and heat transfer, this work takes the one‐dimensional steady flow with homogeneous fluid in wellbores as the analysis object and divides the wellbore into finite micro‐segments. Then we derive the explicit finite difference model (EFDM) about pressure in a certain micro‐segment of wellbore, based on the mass and momentum equations. Next we deduce the EFDM about temperature reflecting the wellbore heat transfer in the same micro‐segment according to the energy balance equation. After that, a coupling calculation method for the EFDM about pressure and temperature is presented. Finally, a comparison of the simulation results of the EFDM, other models, and the log data from engineering is implemented, which demonstrates that the prediction results of the EFDM are more consistent with the log data than the results of other models. Therefore, the reliability of the EFDM about pressure and temperature and their coupling calculation method is verified. Discussion of the friction loss in the energy balance equation and the isobaric specific heat capacity showed that both have a great impact on wellbore temperature distribution, which means the friction loss should not be ignored and the isobaric specific heat capacity should not be assumed as a constant in applications. Generally, the prediction of wellbore pressure and temperature distribution and the comprehension of the internal essence of wellbore flow and heat transfer will be effectively promoted by this work. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.

Investigation on the Relationship between Wellhead Injection Pressure and Injection Rate for Practical Injection Control in CO2 Geological Storage Projects

“…Based on that, the more convenient method is to control the wellhead injection pressure [13], which has been verified sufficiently in In Salah [14] and Ketzin and Shenhua CCS projects [13,15]. To obtain the maximum allowable wellhead injection pressure for CCS projects, Carroll and Lui [16] and Hashim and Maloka [17] analyzed the main influential factors of wellhead pressure, and Streit and Hillis [18], Rutqvist et al [10], and Gapillou et al [19] proposed some approximate 2 Geofluids estimation methods and engineering experience.…”

Evaluating Reservoir Risks and Their Influencing Factors during CO2 Injection into Multilayered Reservoirs

“…Obtaining an analytic solution from Nordbotten's equation is almost impossible. According to the derivation, by introducing two-phase mobility into the Darcy formula of a single-phase flow and assuming that the CO 2 plume is radially symmetric, as suggested by Wu et al [20,21] and Bai et al [12], the mass flow rate , which enters the -th reservoir from the wellbore, can be expressed as follows:…”