Preliminary Numerical Analysis for a Naptha Co-Injection Test During SAGD

Boak, J.; Palmgren, C.

doi:10.2118/2004-001

Cited by 6 publications

(2 citation statements)

References 4 publications

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“…We conducted a sensitivity study on the grid size and determined that a grid size of 3.28 Â 3.28 ft is adequate. This is consistent with the findings of Boak and Palmgren (2004). Use of smaller grid size (1.64 Â 1.64 ft and 0.82 Â 0.82 ft) does not alter the results significantly.…”

Section: Model Descriptionsupporting

confidence: 91%

New Insights Into Steam/Solvent-Coinjection-Process Mechanism

et al. 2013

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We present results of a detailed investigation of the steam/ solvent-coinjection-process mechanism by use of a numerical model with homogeneous reservoir properties and various solvents. We describe condensation of steam/solvent mixture near the chamber boundary. We present a composite picture of the important phenomena occurring in the different regions of the reservoir and their implications for oil recovery. We compare performances of various solvents and explain the reasons for the observed differences. An improved understanding of the process mechanism will help with selecting the best solvent and developing the best operating strategy for a given reservoir. Results indicate that as the temperature drops near the chamber boundary, steam starts condensing first because its mole fraction in the injected steam/solvent mixture (and hence its partial pressure and the corresponding saturation temperature) is much higher than the solvent's. As temperature declines toward the chamber boundary and steam continues to condense, the vapor phase becomes increasingly richer in solvent. At the chamber boundary where the temperature becomes equal to the condensation temperature of both steam and solvent at their respective partial pressures, both condense simultaneously. Thus, contrary to steam-only injection, where condensation occurs at the injected steam temperature, condensation of steam/solvent mixture is accompanied by a reduction in temperature in the condensation zone and the farther regions. However, there is little change in temperature in the central region of the steam chamber. The condensed steam/solvent mixture drains outside the chamber, leading to the formation of a mobile liquid stream (drainage region) where heated oil, condensed solvent, and water flow together to the production well. The condensed solvent mixes with the heated oil and further reduces its viscosity. The additional reduction in viscosity by solvent more than offsets the effect of reduced temperature near the chamber boundary. As the steam chamber expands laterally because of continued injection and as temperature in the hitherto drainage region increases, a part of the condensed solvent mixed with oil evaporates. This lowers the residual oil saturation (ROS) in the steam chamber. Therefore, ultimate oil recovery with the steam/solvent-coinjection process is higher than that in steam-only injection. The higher the solvent concentration in oil at a location, the greater is the reduction in the ROS there. Our explanation is corroborated by the experimental results reported in the literature, which show smaller ROS in the steam chamber after a steam/solvent-coinjection process. A lighter solvent has a lower viscosity, a higher volatility, and a higher molar concentration of solvent in the drainage region. Thus, a lighter solvent causes a greater reduction in the viscosity of the heated oil and also leads to a lower ROS. Therefore, the lightest condensable solvent (butane, under the conditions investigated) provides the most favorable results i...

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Section: Model Descriptionsupporting

confidence: 91%

New Insights Into Steam/Solvent-Coinjection-Process Mechanism

et al. 2013

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“…Boak and Palmgren (2007) tested propane, pentane, or naphtha coinjection in a pad-scale simulation model. 194 All of them showed positive results compared with SAGD. Moreover, an increase in solvent concentration resulted in an improved SOR.…”

Section: ■ Css Follow-up Processes and Simulationmentioning

confidence: 95%

A Critical Review of Reservoir Simulation Applications in Key Thermal Recovery Processes: Lessons, Opportunities, and Challenges

Yang

Nie

et al. 2021

Energy Fuels

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After a cyclic steam stimulation (CSS) process achieved accidental success in recovering heavy oil resources in the 1960s, thermal recovery processes started to unlock the door of in situ recovery of heavy oil and bitumen resources. After five decades of development, many thermal recovery processes have been developed, among which CSS and steam-assisted gravity drainage (SAGD) are two main commercialized processes. With the support of laboratory and field data, reservoir simulation can help engineers and researchers to understand recovery mechanisms, optimize operations, and forecast performance of either existing or emerging processes. In this paper, we present a critical review of applications of reservoir simulation on CSS, CSS follow-ups (steamflooding, liquid addition to steam for enhancing recovery (LASER), and in situ combustion), SAGD, solvent-assisted SAGD, and SAGD noncondensable gas (NCG) coinjection processes. This review and the analyses of these processes provide not only their clarifications from thermal simulation lessons but also an extensive summary of challenges still faced by industry. Moreover, they shed light on future research directions and opportunities for thermal recovery processes.

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New Hybrid Steam-Solvent Processes for the Recovery of Heavy Oil and Bitumen

Nasr¹,

Ayodele²

2006

Abu Dhabi International Petroleum Exhibition and Conference

106

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Canada has declining reserves of conventional oil, but vast reserves of heavy oil and bitumen. Over 90% of the world's heavy oil and bitumen trapped in sandstones and carbonates are deposited in Canada and Venezuela. Up to 80% of estimated reserves could be recovered by in-situ thermal operation. The current in-situ thermal technologies such as cyclic steam stimulation (CSS), steam flooding and steam-assisted gravity drainage (SAGD) are energy intensive and use large quantities of fresh water. Increasing pressure of environmental concerns and the threat of a carbon tax will make it imperative to find new oil extraction technologies that are less energy intensive and that use less water. Combining technologies in the form of hybrid steam-solvent processes offer the potential of higher oil rates and recoveries, but at less energy and water consumption than processes such as SAGD. At the Alberta Research Council, new hybrid steam-solvent processes have been undergoing development in recent years. The Expanding Solvent-SAGD (ES-SAGD)(1–2), is aimed at improving and extending SAGD performance by solvent addition to steam. The improvements include higher and faster drainage rates, lower energy and water requirements and reduced green house gas (GHG) emissions. The Thermal Solvent Hydrid process focuses on combining solvent with a small amount of steam in a VAPEX (vapour extraction) process (3–4). This process offers the potential of higher rates than cold solvent VAPEX at less energy consumption than SAGD. Hybrid steam-solvent processes, when fully developed, will extract oil at lower cost than SAGD and will also open currently marginal resources for exploitation, increasing oil reserves. This paper presents and discusses the principal concepts and key parameters for the new hybrid steam-solvent processes and compares expected performance to SAGD. Introduction The goal of this paper is to provide a summary of the hybrid steam-solvent processes developed at the Alberta Research Council (ARC), which include ES-SAGD and thermal solvent hybrid and provide some laboratory and field examples of these and other steam-solvent hydrid processes developed in recent years. The hybrid steam-solvent processes results at ARC illustrated the potential to develop an improved process that will significantly reduce energy, water and GHG intensity as compared to SAGD, therefore reducing operating cost while maintaining economic oil recovery rates. ES-SAGD laboratory experimental results in Athabasca illustrate 17–30% increase in oil production over that from SAGD, for the same amount of steam injected. This indicates an improvement in oil-steam ratio (OSR) by the same magnitude. More importantly, the experimental results indicate that the time required to produce the same amount of oil in ES-SAGD could be half that of SAGD. Such accelerated oil production results in significant increase in oil rates and reduction (∼50%) in steam requirements. As a consequence, natural gas burning, water requirement and GHG emissions would be reduced. This is quite significant given the large production volumes from commercial SAGD projects. The thermal solvent hybrid experimental results at ARC provided data for comparison of the process with other low energy intensity processes, like thermal solvent reflux and VAPEX(3–4). Expanding Solvent SAGD (ES-SAGD) Concept and Principles of ES-SAGD In ES-SAGD recovery process(1,2), a solvent or a solvent mixture is co-injected with steam in a hybrid process, as opposed to the injection of only steam in the SAGD process or only solvent in the VAPEX process. In the ES-SAGD process, the solvent or solvent mixture additive, whose vapourization thermodynamic behaviour is similar, or close, to that of water thermodynamic behaviour for a given reservoir condition is considered the most appropriate.

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Preliminary Numerical Analysis for a Naptha Co-Injection Test During SAGD

Cited by 6 publications

References 4 publications

New Insights Into Steam/Solvent-Coinjection-Process Mechanism

New Insights Into Steam/Solvent-Coinjection-Process Mechanism

A Critical Review of Reservoir Simulation Applications in Key Thermal Recovery Processes: Lessons, Opportunities, and Challenges

New Hybrid Steam-Solvent Processes for the Recovery of Heavy Oil and Bitumen

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