Applicability of Vapor Extraction Process to Problematic Viscous Oil Reservoirs

2003 ◽  
Author(s):  
Kulada Karmaker ◽  
Brij B. Maini
Keyword(s):  
Extraction Process ◽  
Oil Reservoirs ◽  
Vapor Extraction ◽  
Viscous Oil

Steady State Analysis of Heated Soil Vapor Extraction Process With Air Sparging

2005 ◽  
Author(s):  
P. M. Mohan Das ◽  
R. S. Amano ◽  
T. Roy ◽  
J. Jatkar
Keyword(s):  
Extraction Process ◽  
Soil Vapor Extraction ◽  
Air Sparging ◽  
Saturated Zone ◽  
Vapor Extraction ◽  
Combined System ◽  
Discrete Phase Modeling ◽  
Discrete Phase ◽  
Time Required ◽  
Heated Soil

Heated Soil Vapor Extraction (HSVE), developed by Advanced Remedial Technology is a Soil remediation process that has gained significant attention during the past few years. HSVE along with Air sparging has been found to be an effective way of remediating soil of various pollutants including solvents, fuels and Para-nuclear aromatics. The combined system consists of a heater/boiler that pumps and circulates hot oil through heating wells, a blower that helps to suck the contaminants out through the extraction well, and air sparging wells that extend down to the saturated region in the soil. Both the heating wells and extraction wells are installed vertically in the saturated region in contaminated soil and is welded at the bottom and capped at the top. The heat source heats the soil and the heat is transported inside the soil by means of conduction and convection. This heating of soil results in vaporization of the gases, which are then absorbed by the extraction well. Soil vapor extraction cannot remove contaminants in the saturated zone of the soil that lies below the water table. In that case air sparging may be used. In air sparging system, air is pumped into the saturated zone to help flush the contaminants up into the unsaturated zone where the contaminants are removed by SVE well. In this analysis an attempt has been made to predict the behavior of different chemicals in the unsaturated and saturated regions of the soil. This analysis uses the species transport and discrete phase modeling to predict the behavior of different chemicals when it is heated and absorbed by the extraction well. Such an analysis will be helpful in predicting the parameters like the distance between the heating and extraction wells, the temperature to be maintained at the heating well and the time required for removing the contaminants from the soil.

Solvent Injection Strategy for Low-Temperature Production from Fractured Viscous Oil Reservoirs

2014 ◽  
Vol 28 (7) ◽  
pp. 4342-4354 ◽  
Author(s):  
Kelli Rankin ◽  
Bradley Nguyen ◽  
Johan van Dorp ◽  
Marco Verlaan ◽  
Orlando Castellanos-Diaz ◽  
...  
Keyword(s):  
Low Temperature ◽  
Oil Reservoirs ◽  
Injection Strategy ◽  
Solvent Injection ◽  
Viscous Oil

Upscaling Study of Vapor Extraction Process Through Numerical Simulation

2012 ◽  
Vol 95 (3) ◽  
pp. 697-715 ◽  
Author(s):  
S. Xu ◽  
F. Zeng ◽  
Y. Gu ◽  
K. D. Knorr
Keyword(s):  
Numerical Simulation ◽  
Extraction Process ◽  
Vapor Extraction

Revisiting the Butler-Mokrys Model for the Vapor-Extraction Process

SPE Journal ◽  
2019 ◽  
Vol 24 (02) ◽  
pp. 511-521
Author(s):  
V.. Mohan ◽  
P.. Neogi ◽  
B.. Bai
Keyword(s):  
Concentration Profile ◽  
Heavy Oil ◽  
Extraction Process ◽  
Previous Model ◽  
Oil Reservoir ◽  
Vapor Extraction ◽  
Oil Viscosity ◽  
Solvent Vapor ◽  
Vapor Interface ◽  
Heavy Oil Reservoir

Summary The dynamics of a process in which a solvent in the form of a vapor or gas is introduced in a heavy-oil reservoir is considered. The process is called the solvent vapor-extraction process (VAPEX). When the vapor dissolves in the oil, it reduces its viscosity, allowing oil to flow under gravity and be collected at the bottom producer well. The conservation-of-species equation is analyzed to obtain a more-appropriate equation that differentiates between the velocity within the oil and the velocity at the interface, which can be solved to obtain a concentration profile of the solvent in oil. We diverge from an earlier model in which the concentration profile is assumed. However, the final result provides the rate at which oil is collected, which agrees with the previous model in that it is proportional to h, where h is the pay-zone height; in contrast, some of the later data show a dependence on h. Improved velocity profiles can capture this dependence. A dramatic increase in output is seen if the oil viscosity decreases in the presence of the solvent, although the penetration of the solvent into the oil is reduced because under such conditions the diffusivity decreases with decreased solvent. One other important feature we observe is that when the viscosity-reducing effect is very large, the recovered fluid is mainly solvent. Apparently, some optimum might exist in the solubility φo, where the ratio of oil recovered to solvent lost is the largest. Finally, the present approach also allows us to show how the oil/vapor interface evolves with time.

An Experimental Study of Improving Viscous Oil Recovery by Using Hybrid Enhanced Oil Recovery Techniques: A Case Study of Alaska North Slope Reservoir

SPE Journal ◽  
2021 ◽  
pp. 1-20
Author(s):  
Yaoze Cheng ◽  
Yin Zhang ◽  
Abhijit Dandekar ◽  
Jiawei Li
Keyword(s):  
Oil Recovery ◽  
Oil Reservoirs ◽  
Viscosity Reduction ◽  
Displacement Efficiency ◽  
Natural Sand ◽  
Ζ Potential ◽  
Low Salinity ◽  
Viscous Oil ◽  
Reservoir Conditions ◽  
Salinity Water

Summary Shallow reservoirs on the Alaska North Slope (ANS), such as Ugnu and West Sak-Schrader Bluff, hold approximately 12 to 17 × 109 barrels of viscous oil. Because of the proximity of these reservoirs to the permafrost, feasible nonthermal enhanced oil recovery (EOR) methods are highly needed to exploit these oil resources. This study proposes three hybrid nonthermal EOR techniques, including high-salinity water (HSW) injection sequentially followed by low-salinity water (LSW) and low-salinity polymer (LSP) flooding (HSW-LSW-LSP), solvent-alternating-LSW flooding, and solvent-alternating-LSP flooding, to recover ANS viscous oils. The oil recovery performance of these hybrid EOR techniques has been evaluated by conducting coreflooding experiments. Additionally, constant composition expansion (CCE) tests, ζ potential determinations, and interfacial tension (IFT) measurements have been conducted to reveal the EOR mechanisms of the three proposed hybrid EOR techniques. Coreflooding experiments and IFT measurements have been conducted at reservoir conditions of 1,500 psi and 85°F, while CCE tests have been carried out at a reservoir temperature of 85°F. ζ potential determinations have been conducted at 14.7 psi and 77°F. The coreflooding experiment results have demonstrated that all of the three proposed hybrid EOR techniques could result in much better performance in reducing residual oil saturation than waterflooding and continuous solvent flooding in viscous oil reservoirs on ANS, implying better oil recovery potential. In particular, severe formation damage or blockage at the production end occurred when natural sand was used to prepare the sandpack column, indicating that the natural sand may have introduced some unknown constituents that may react with the injected solvent and polymer, resulting in a severe blocking issue. Our investigation on this is ongoing, and more detailed studies are being conducted in our laboratory. The CCE test results demonstrate that more solvent could be dissolved into the tested viscous oil with increasing pressure, simultaneously resulting in more oil swelling and viscosity reduction. At the desired reservoir conditions of 1,500 psi and 85°F, as much as 60 mol% of solvent could be dissolved into the ANS viscous oil, resulting in more than 31% oil swelling and 97% oil viscosity reduction. Thus, the obvious oil swelling and significant viscosity reduction resulting from solvent injection could lead to much better microscopic displacement efficiency during the solvent flooding. The ζ potential determination results illustrate that LSW resulted in more negative ζ potential than HSW on the interface between sand and water, indicating that lowering the salinity of injected brine could result in the sand surface being more water-wet, but adding polymer to the LSW could not further enhance the water wetness. The IFT measurement results show that the IFT between the tested ANS viscous oil and LSW is higher than that between the tested viscous oil and HSW, which conflicts with the commonly recognized IFT reduction effect by LSW flooding. Thus, the EOR theory of the LSW flooding in our proposed hybrid techniques may be attributed to low-salinity effects (LSEs) such as multi-ion exchange, expansion of electrical double layer, and salting-in effect, while water wetness enhancement may benefit the LSW flooding process to some extent. The LSP’s viscosity is much higher than the viscosities of LSW and solvent, so LSP injection could result in better mobility control in the tested viscous oil reservoirs, leading to improvement of macroscopic sweep efficiency. Combining these EOR theories, the proposed hybrid EOR techniques have the potential to significantly increase oil recovery in viscous oil reservoirs on ANS by maximizing the overall displacement efficiency.

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