Cold Lake bitumens

The Athabasca deposit, along with the neighboring Wabasca, Peace River, and Cold Lake heavy oil deposits, have together been estimated to contain 1.86 X 10 m (>1.17 X 10 bbl) of bitumen. The Vene2uelan deposits may at least contain >1.60 X 10 m (1.0 X 10 bbl) bitumen (2). Deposits of tar sand, each containing >3 x 10 m (20 x 10 bbl) of bitumen, have also been located in the United States, Albania, Italy, Madagascar,... 

Cold Lake 250 immediate phases 9—10 in situ bitumen production iacreased 14,400 3,000 (120,000 -25,000+)... 

Cold Lake (proposed) 250 1997 phases 11—12 in situ bitumen production foUowiag completion of add 2,400 (-20,000)... 

Koch Oil Co., Ltd. Cold Lake 1997-1998 in situ bitumen project 6,000 (50,000)... 

Figure 6 Interfacial tensions for Athabasca, Cold Lake and Peace River bitumen/DJ) systems as a function of temperature and NaCI (0 and 10 g/L) concentration.

Canada s bitumen resources are situated almost entirely within the western province of Alberta (see Fig. 3.13). These deposits are distributed among three regions Athabasca, Cold Lake and Peace River. Approximately 76% of crude bitumen is produced in the Athabasca region, 22% in the Cold Lake region and 2% in the Peace River region. 

For many years, petroleum and heavy oil were very generally defined in terms of physical properties. For example, heavy oil was considered to be a crude oil that had gravity between 10 and 20° API. For example. Cold Lake heavy crude oil (Alberta, Canada) has an API gravity equal to 12°, but extra-heavy oil (such as tar sand bitumen), which requires recovery by nonconventional and nonenhanced methods, has an API gravity in the range 5 to 10°. Residua would vary depending on the temperature at which distillation was terminated, but vacuum residua were usually in the range 2 to 8° API. 

Sulfur compounds in the gas oil fractions from two bitumens (Athabasca oil sand and Cold Lake deposit)> a heavy oil (Lloydminster) from Cretaceous reservoirs along the western Canada sedimentary basin, and a Cretaceous oil from a deep reservoir that may be mature (Medicine River) are investigated. The gas oil distillates were separated to concentrates of different hydrocarbon types on a liquid adsorption chromatographic column. The aromatic hydrocarbon types with their associated sulfur compounds were resolved by gas chromatographic simulated distillation and then by gas solid chromatography. Some sulfur compounds were further characterized by mass spectrometry. The predominant sulfur compounds in these fractions are alkyl-substituted benzo- and dibenzothiophenes with short side chains which have few dominant isomers. 

Cold Lake bitumen obtained by steam injection at 1500 ft (457 m) from the Mannville Pool by Imperial Oil Co. 

Figures 7a and 7b are UV recordings, on the same combined columns (/i-Styragel 500 + 100 A) and at comparable concentrations, of the various resin fractions isolated in the separation of Cold Lake bitumen resins on an anion (Figure 7a) and a cation (Figure 7b) exchanger column. These curves were compared with MW measurements for these fractions by VPO from methylene chloride (Table VI). The various degrees of sample polydispersity of these fractions are noteworthy. However, these chromatograms have one striking feature that is revealed by the comparison of the base fractions from the cation exchanger with the curve of the nC5 eluent from the anion exchanger and, further, the relative positions of the acid and base curves with the MWs of these fractions obtained from VPO measurements in the same solvent.

The separations of resins and asphaltenes under comparable conditions done on the fractions from a common source—Athabasca (in some cases Cold Lake) bitumen—have confirmed a number of postulates that have appeared in the recent literature. 

In the course of our studies on Athabasca and Cold Lake bitumens, the problem of determining the overall composition of a number of samples from cores and from various extraction procedures made it necessary to sacrifice some analytical detail in favor of speed of analysis. Since no comprehensive analytical data on either bitumen were available. 

Cold Lake bitumen from Esso Resources Canada. 

One of the five fractions obtained from distillation of Cold Lake bitumen made by Esso Resources Canada. 

Abercrombie, H.J. (1991) Reservoir processes in steam-assisted recovery of bitumen, Lemin Pilot, Cold Lake, Alberta, Canada composition, mixing and sources of co-produced waters. Appl. Geochem., 6, 495-508. 

Hutcheon, I. Abercrombie, H.J. (1990) Fluid-rock interaction in thermal recovery of bitumen. Tucker Lake Pilot, Cold Lake, Alberta. In Prediction of Reservoir Quality Through Chemical Modeling (Eds Meshri, I.D. Ortoleva, P.J). Mem. Am. Ass. Petrol. Geol., Tulsa, 49, 161-170. 

In many petroleum reservoirs around the world, reservoir fluid composition has been found to very with location and depth. Patel found the viscosity of Athabasca, Peace River, Wabasca and Cold Lake bitumens to vary with depth of the formation. Schulte explained the compositional variations within a hydrocarbon column by gravity segregation phenomenon. However, he found that the extent of variation to be higher with larger aromatic fractions in the hydrocarbon fluid. Hirschberg concluded that the heavy polar components play a key role in compositional and oil viscosity variation and in particular, identified asphaltene segregation to have a dominant effect. Hirschberg found that the... 

Conversion (upgrading) of bitumen and heavy oils to distillate products requires reduction of the MW and boiling point of the components of the feedstocks. The chemistry of this transformation to lighter products is extremely complex, partly because the petroleum feedstocks are complicated mixtures of hydrocarbons, consisting of 10 to 10 different molecules. Any structural information regarding the chemical nature of these materials would help to understand the chemistry of the process and, hence, it would be possible to improve process yields and product quality. However, because of the complexity of the mixture, the characterization of entire petroleum feedstocks and products is difficult, if not impossible. One way to simpHfy this molecular variety is to separate the feedstocks and products into different fractions (classes of components) by distillation, solubility/insolubility, and adsorption/desorption techniques. For bitumen and heavy oils, there are a number of methods that have been developed based on solubility and adsorption. The most common standard method used in the petroleum industry for separation of heavy oils into compound classes is SARA (saturates, aromatics, resins, and asphaltenes) analysis. Typical SARA analyses and properties for Athabasca and Cold Lake bitumens, achieved using a modified SARA method, are shown in Table 1. For comparison, SARA analysis of Athabasca bitumen by the standard ASTM method is also shown in this table. The discrepancy in the results between the standard and modified ASTM methods is a result of the aromatics being eluted with a... 

Athabasca bitumen VB and Forties VB have similar pitch contents (fractions boiling above 525°C) and that the concentrations of subcomponents of maltenes are also comparable. However, CLVB (Cold Lake vacuum bottoms) has much lower pitch content and the product composition cannot directly be compared with the other two feedstocks. 

Clarke, P. Pruden, B. Asphaltene precipitation Irom Cold Lake and Athabasca bitumen. Pet Sci. Technol, 1998,16(3 4), 287-305. 

Khulbe, K.C., Sachdev, A.K., Maim, R.S., Davis, S. 1984. TGA studies of asphaltenes derived from cold lake (Canada) bitumen. Fuel Process. Technol. 8 259-266. 

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