scholarly journals Experimental study of the supercritical CO 2 diffusion coefficient in porous media under reservoir conditions

2019 ◽  
Vol 6 (6) ◽  
pp. 181902 ◽  
Author(s):  
Junchen Lv ◽  
Yuan Chi ◽  
Changzhong Zhao ◽  
Yi Zhang ◽  
Hailin Mu

Reliable measurement of the CO 2 diffusion coefficient in consolidated oil-saturated porous media is critical for the design and performance of CO 2 -enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects. A thorough experimental investigation of the supercritical CO 2 diffusion in n -decane-saturated Berea cores with permeabilities of 50 and 100 mD was conducted in this study at elevated pressure (10–25 MPa) and temperature (333.15–373.15 K), which simulated actual reservoir conditions. The supercritical CO 2 diffusion coefficients in the Berea cores were calculated by a model appropriate for diffusion in porous media based on Fick's Law. The results show that the supercritical CO 2 diffusion coefficient increases as the pressure, temperature and permeability increase. The supercritical CO 2 diffusion coefficient first increases slowly at 10 MPa and then grows significantly with increasing pressure. The impact of the pressure decreases at elevated temperature. The effect of permeability remains steady despite the temperature change during the experiments. The effect of gas state and porous media on the supercritical CO 2 diffusion coefficient was further discussed by comparing the results of this study with previous study. Based on the experimental results, an empirical correlation for supercritical CO 2 diffusion coefficient in n -decane-saturated porous media was developed. The experimental results contribute to the study of supercritical CO 2 diffusion in compact porous media.

2012 ◽  
Vol 524-527 ◽  
pp. 1807-1810
Author(s):  
Hao Chen ◽  
Sheng Lai Yang ◽  
Fang Fang Li ◽  
San Bo Lv ◽  
Zhi Lin Wang

CO2 flooding process has been a proven valuable tertiary enhanced oil recovery (EOR) technique. In this paper, experiment on extractive capacity of CO2 in oil saturated porous media was conducted under reservoir conditions. The main objectives of the study are to evaluate extractive capacity of CO2 in oil saturated natural cores and improve understanding of the CO2 flooding mechanisms, especially in porous media conditions. Experimental results indicated that oil production decreases while GOR increases with extractive time increases. the changes of the color and state of the production oil shows that oil component changes from light to heavy as extractive time increases. In addition, no oil was produced by water flooding after extractive experiment. Based on the experimental results and phenomena, the main conclusion drawn from this study is that under supercritical condition, CO2 has very powerful extractive capacity. And the application of CO2 flooding is recommended for enhancing oil recovery.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6456
Author(s):  
Ewa Knapik ◽  
Katarzyna Chruszcz-Lipska

Worldwide experiences related to geological CO2 storage show that the process of the injection of carbon dioxide into depleted oil reservoirs (CCS-EOR, Carbon Capture and Storage—Enhanced Oil Recovery) is highly profitable. The injection of CO2 will allow an increasing recovery factor (thus increasing CCS process profitability) and revitalize mature reservoirs, which may lead to oil spills due to pressure buildups. In Poland, such a solution has not yet been implemented in the industry. This work provides additional data for analysis of the possibility of the CCS-EOR method’s implementation for three potential clusters of Polish oil reservoirs located at a short distance one from another. The aim of the work was to examine the properties of reservoir fluids for these selected oil reservoirs in order to assure a better understanding of the physicochemical phenomena that accompany the gas injection process. The chemical composition of oils was determined by gas chromatography. All tested oils represent a medium black oil type with the density ranging from 795 to 843 g/L and the viscosity at 313 K, varying from 1.95 to 5.04 mm/s. The content of heavier components C25+ is up to 17 wt. %. CO2–oil MMP (Minimum Miscibility Pressure) was calculated in a CHEMCAD simulator using the Soave–Redlich–Kwong equation of state (SRK EoS). The oil composition was defined as a mixture of n-alkanes. Relatively low MMP values (ca. 8.3 MPa for all tested oils at 313 K) indicate a high potential of the EOR method, and make this geological CO2 storage form more attractive to the industry. For reservoir brines, the content of the main ions was experimentally measured and CO2 solubility under reservoir conditions was calculated. The reservoir brines showed a significant variation in properties with total dissolved solids contents varying from 17.5 to 378 g/L. CO2 solubility in brines depends on reservoir conditions and brine chemistry. The highest calculated CO2 solubility is 1.79 mol/kg, which suggest possible CO2 storage in aquifers.


Author(s):  
Qichen Zhang ◽  
Xiaodong Kang ◽  
Huiqing Liu ◽  
Xiaohu Dong ◽  
Jian Wang

AbstractCurrently, the reservoir heterogeneity is a serious challenge for developing oil sands with SAGD method. Nexen’s Long Lake SAGD project reported that breccia interlayer was widely distributed in lower and middle part of reservoir, impeding the steam chamber expansion and heated oil drainage. In this paper, two physical experiments were conducted to study the impact of breccia interlayer on development of steam chamber and production performance. Then, a laboratory scale numerical simulation model was established and a history match was conducted based on the 3D experimental results. Finally, the sensitivity analysis of thickness and permeability of breccia layer was performed. The influence mechanism of breccia layer on SAGD performance was analyzed by comparing the temperature profile of steam chamber and production dynamics. The experimental results indicate that the existence of breccia interlayer causes a thinner steam chamber profile and longer time to reach the peak oil rate. And, the ultimate oil recovery reduced 15.8% due to much oil stuck in breccia interlayer areas. The numerical simulation results show that a lower permeability in breccia layer area has a serious adverse impact on oil recovery if the thickness of breccia layer is larger, whereas the effect of permeability on SAGD performance is limited when the breccia layer is thinner. Besides, a thicker breccia layer can increase the time required to reach the peak oil rate, but has a little impact on the ultimate oil recovery.


2019 ◽  
Vol 38 (4) ◽  
pp. 733-750
Author(s):  
Sébastien Chailleux

Analyzing the case of France, this article aims to explain how the development of enhanced oil recovery techniques over the last decade contributed to politicizing the subsurface, that is putting underground resources at the center of social unrest and political debates. France faced a decline of its oil and gas activity in the 1990s, followed by a renewal with subsurface activity in the late 2000s using enhanced oil recovery techniques. An industrial demonstrator for carbon capture and storage was developed between 2010 and 2013 , while projects targeting unconventional oil and gas were pushed forward between 2008 and 2011 before eventually being canceled. We analyze how the credibility, legitimacy, and governance of those techniques were developed and how conflicts made the role of the subsurface for energy transition the target of political choices. The level of political and industrial support and social protest played a key role in building project legitimacy, while the types of narratives and their credibility determined the distinct trajectories of hydraulic fracturing and carbon capture and storage in France. The conflicts over enhanced oil recovery techniques are also explained through the critical assessment of the governance framework that tends to exclude civil society stakeholders. We suggest that these conflicts illustrated a new type of politicization of the subsurface by merging geostrategic concerns with social claims about governance, ecological demands about pollution, and linking local preoccupations to global climate change.


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