Steam Alternating Solvent Process: Lab Test and Simulation

Zhao, Lulu; Nasr, T.N.; Huang, Haiping; Beaulieu, Gilles; Heck, G.; Golbeck, H.

doi:10.2118/2004-044

Cited by 37 publications

(20 citation statements)

References 10 publications

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“…Compared with conventional SAGD, this process can improve oil-production rates with fewer energy and water requirements. Zhao (2004) and Zhao et al (2004) proposed a new heavyoil-recovery process, the steam-alternating-solvent (SAS) process. The process is intended to combine the advantages of the SAGD and VAPEX processes to minimize the energy input per unit oil recovered.…”

Section: Introductionmentioning

confidence: 99%

Light- and Heavy-Solvent Impacts on Solvent-Aided-SAGD Process: A Low-Pressure Experimental Study

Mamora

2011

Journal of Canadian Petroleum Technology

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Coinjecting solvent with steam under steam-assisted gravitydrainage (SAGD) process to reduce the required steam amount for heavy-oil production has gained importance in recent years. The objective of this experimental study was to investigate the drainage mechanism of coinjecting light and heavy solvents to improve production performance.A 2D cross-sectional low-pressure scaled physical model was constructed. The model represented a half-symmetry cross section of a typical SAGD drainage in the Athabasca formation. Using an infrared camera, we visualized and recorded expansion of the steam chamber and temperature distribution. The fluid injection rate, pressure, and temperature, and produced-liquid volumes were also recorded.The results show that the relative condensation time of solvent and steam results in different production performances. Light solvent, delivered in the vapour phase to the entire fluid interface, reduces the bitumen viscosity along the whole vapour-chamber boundary, but it may build a thick gas blanket that may reduce the heat transfer from the high-temperature vapour chamber to the surrounding low-temperature bitumen. Coinjecting a suitable multicomponent-solvent mixture, including a heavy solvent, can enhance the production performance by altering the condensation dynamics of the light hydrocarbons.The conclusions from this study can be used to design suitable solvent mixtures and coinjection strategies to deliver a higher production rate, higher recovery factor with lower cumulative steam required/oil ratio (CSOR), and lower cumulative energy required for oil production (CEOR) from SAGD performance.

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Section: Introductionmentioning

confidence: 99%

Light- and Heavy-Solvent Impacts on Solvent-Aided-SAGD Process: A Low-Pressure Experimental Study

Mamora

2011

Journal of Canadian Petroleum Technology

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“…Therefore, several researchers tried to investigate the performance of solvent co-injection with steam processes to enhance the recovery of bitumen and heavy oil using conventional vertical wells (Farouq Ali and Abad, 1976;Redford, 1982;Shu and Hartman, 1988;Sarma et al, 1996). Thanks to developments in horizontal well drilling technologies during the last two decades, other hybrid methods were introduced mainly based on SAGD and VAPEX concepts such as solvent-aided process (SAP) (Gupta et al, 2005), expanding solvent SAGD (ES-SAGD) (Nasr et al, 2002 and2003), steam-alternating solvent (SAS) (Zhao et al, 2005 and, N-SOLV (Nenniger, 2000), thermal solvent recovery (Frauenfeld et al, 2007) and naphtha-assisted gravity drainage (NAGD) (Palmgren and Edmunds, 1995). Nasr et al (2002) presented a new hybrid method, namely expanding solvent SAGD (ES-SAGD) after several comprehensive experiments to enhance the efficiency of SAGD process and compensate its drawbacks.…”

Section: Introductionmentioning

confidence: 99%

“…Other privileges of ES-SAGD over SAGD are improvement in cumulative steam-oil ratio (CSOR), less amount of water consumption and lower GHG emissions. Zhao et al (2005) carried out 2-D lab experiments using high-pressure/high-temperature model to evaluate the steam alternating solvent process. The model was filled with oil sample from Cold Lake reservoir and mixture of methane and propane was applied as the solvent in their experiment.…”

Section: Introductionmentioning

confidence: 99%

“…Different experiments were conducted to evaluate the advantages of solvent co-injection processes (SCI) over SAGD by several researchers (Nasr et al, 2002 and2003;Nasr and Ayodele, 2006;Ayodele et al, 2008;Ayodele et al, 2009;Ayodele et al, 2010;Mohammadzadeh et al, 2012;Ardali et al, 2011). These SCI experiments have been performed at different conditions from low pressures of 60 kPa (Li and Mamora, 2010) to medium pressures of 550 kPa (Ardali et al, 2012) and 1500 kPa (Ivory et al, 2008) and even higher pressures of 2200 kPa (Zhao et al, 2005) using different solvent types as light as propane to heavier ones such as n-C 8 , Naphtha and Xylene with different concentrations. The conducted experiments represented improvements including higher and faster drainage rates, lower energy and water requirements and reduced green house gas (GHG) emissions in SCI process compared to SAGD.…”

Section: Introductionmentioning

confidence: 99%

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Application of Solvent Alternating SAGD Process to Improve SAGD Performance in Athabasca Bitumen Reservoir

Souraki

Torsater

Ghahfarokhi

et al. 2013

SPE Western Regional &Amp; AAPG Pacific Section Meeting 2013 Joint Technical Conference

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Canada, Venezuela and United States contain the largest portions of heavy oil and bitumen resources throughout the world. The problem associated with this type of resource is very viscous fluid flow. The EOR methods applied to heavy oil reservoirs are mainly based on viscosity reduction processes such as heating the reservoir and solvent injection. Heating, in the form of hot water flooding, steam injection and in-situ combustion dramatically reduces the viscosity of heavy oil and bitumen, but it has green house gas (GHG) emission problems. Diffusion of solvents in heavy oil makes it lighter and therefore mobile and producible via production well. Diffusion of solvent is a very tardy process while time is very important in oil industry and any delay results in extra costs. Recently, hybrid methods like solvent and steam co-injection, steam alternating solvent injection (SAS) have been introduced to solve the mentioned problems, while benefiting from the advantages of heat and solvent.Several simulation studies were performed to evaluate and compare the performance of steam assisted gravity drainage (SAGD) and steam alternating solvent (SAS) processes. Athabasca bitumen reservoir properties were used. Effects of some reservoir and fluid parameters such as thickness, porosity, vertical to horizontal permeability ratio and viscosity were assessed and compared for both processes. Experimental viscosity data of Athabasca and Cold lake bitumen were applied to evaluate the viscosity effect. In addition, sensitivity analysis was carried out on injection time intervals of solvent, solvent type and concentration.Results revealed high recovery of bitumen and appropriate steam-oil ratio (SOR) for both processes. However, SAS showed better performance using hexane as a solvent. Lower porosity, vertical to horizontal permeability ratio and thickness resulted in higher SOR for SAGD process while they had no major effect on SAS. Higher concentration of injected solvent resulted in faster recovery performance and lower SOR. Pentane and heptane were used as alternatives for hexane to investigate the impact of the selected solvent. They divulged almost the same results as hexane. Different injection intervals of 3, 6, 9 months and a year were also studied and the analogous results were obtained.

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“…A typical high quality SAGD project exhibiting a wellhead SOR of 2.5 will require the consumption of ~20% of the bitumen produced to generate steam (based on 80% conversion efficiency in the boiler). There have been many authors (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) to improve the energy efficiency of the process and also to potentially increase the production rate. If successful, such steam-solvent processes would be economically beneficial.…”

Section: Introductionmentioning

confidence: 99%

Design of Steam-Hexane Injection Wells For Gravity Drainage Systems

McCormack

2009

Journal of Canadian Petroleum Technology

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The steam-assisted gravity drainage (SAGD) process has been demonstrated to be commercially viable for the recovery of bitumen from the Athabasca Oil Sands region. One of the potential long-term concerns with the process is the relatively high use of energy. The majority of the projects underway have steam-oil ratios (SOR's) in the range of 2.5 to 3.5. This translates into combustion of approximately 20 -28% of the energy contained in the oil produced. To reduce the current level of energy consumption, many studies have investigated the addition of solvents to the steam. A small number of field trials have been conducted, with apparently encouraging results. The use of hexane, or a similar commercial grade naphtha mixture, as a solvent appears promising, as it would closely match the vapour pressure curve of steam and would tend to flow and condense with the steam.This study presents the results of numerical investigations regarding the implications of the addition of hexane to steam with respect to the design of SAGD solvent injection wells.This study found that the SOR at full depletion of a steamhexane SAGD, in the absence of a wind-down strategy, would be improved over that for conventional SAGD only by the degree that heat losses to the over-and underburden are reduced due to more rapid bitumen production rates. At short and intermediate

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Steam Alternating Solvent Process: Lab Test and Simulation

Cited by 37 publications

References 10 publications

Light- and Heavy-Solvent Impacts on Solvent-Aided-SAGD Process: A Low-Pressure Experimental Study

Light- and Heavy-Solvent Impacts on Solvent-Aided-SAGD Process: A Low-Pressure Experimental Study

Application of Solvent Alternating SAGD Process to Improve SAGD Performance in Athabasca Bitumen Reservoir

Design of Steam-Hexane Injection Wells For Gravity Drainage Systems

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