In-situ bitumen

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)... 

P. R. Tremaine, E. E. Isaacs, and J. A. Boon, Hydrothermal chemistry applied to in situ bitumen recovery. Chem. Can. April, 29-33 (1983). 

In situ bitumen recovery from tar sands promises to have a lower environmental impact than surface mining and extraction. Water recovered with the bitumen from steam drive in situ tar sands processing requires treatment before reuse or discharge. 

Fig. 5.3.3 In situ bitumen removal apparatus from tar sands...

In principle, the nonmining recovery of bitumen from tar sand deposits is an enhanced oil recovery technique and requires the injection of a fluid into the formation through an injection weU. This leads to the in situ displacement of the bitumen from the reservoir and bitumen production at the surface through an egress (production) weU. There are, however, several serious constraints that are particularly important and relate to the bulk properties of the tar sand and the bitumen. In fact, both recovery by fluid injection and the serious constraints on it must be considered in toto in the context of bitumen recovery by nonmining techniques (see PETROLEUM, ENHANCED OIL RECOVERY). 

Recovering the bitumen is not easy, and the deposits are either strip-mined if they are near the surface, or recovered in situ if they are in deeper beds. The bitumen could be extracted by using hot water and steam and adding some alkali to disperse it. The produced bitumen is a very thick material having a density of approximately 1.05 g/cm. It is then subjected to a cracking process to produce distillate fuels and coke. The distillates are hydrotreated to saturate olefinic components. Table 1-8 is a typical analysis of Athabasca bitumen. ... 

Polyalkylene polyamine salts are prepared by contacting polyamines with organic or inorganic acids. The polyamines have a molecular weight of at least 1000 Dalton and ranging up to the limits of water solubility [1185]. In a process of demulsification of the aqueous phase of the broken bitumen emulsions, the pH is adjusted to deactivate the demulsifier so that the water may be used in subsequent in situ hot water or steam floods of the tar sand formation. 

Preliminary work showed that first order reaction models are adequate for the description of these phenomena even though the actual reaction mechanisms are extremely complex and hence difficult to determine. This simplification is a desired feature of the models since such simple models are to be used in numerical simulators of in situ combustion processes. The bitumen is divided into five major pseudo-components coke (COK), asphaltene (ASP), heavy oil (HO), light oil (LO) and gas (GAS). These pseudo-components were lumped together as needed to produce two, three and four component models. Two, three and four-component models were considered to describe these complicated reactions (Hanson and Ka-logerakis, 1984). 

Kinetics and Energetics of Oxidation of Bitumen in Relation to In Situ Combustion Processes... 

Around 25% of in-situ production currently comes from primary (non-thermal) production, so-called cold heavy-oil production with sand (CHOPS), where the bitumen is co-produced with sand through the use of specialised pumps (the same technology is also used for conventional heavy oil production). A significant difference between primary bitumen and conventional heavy-oil production, however, is the amount of sand that is co-produced, which can be two to three times higher. Primary production has the advantage of being cheap, but recovery rates are, at 5% to 10%, very low. The share of primary production is projected to decline in the future. 

Upgrading and refinery capacity While essentially all of the mined bitumen is upgraded in Alberta, the majority of in-situ production is shipped as bitumen blend with a light diluent to refineries in the United States that are suitably equipped to handle such feedstock. This historical split needs to be overcome in the future and further upgrading capacities will have to be installed in Canada, especially to reduce the need for diluents. In addition, the proposed extension of synthetic-crude-oil supply will require new refinery capacities, either in Canada or the United States. 

Of the above-mentioned challenges of oil-sands production, the heavy dependence on natural gas is among the most critical. Table 3.5 shows the specific natural gas demand per barrel of bitumen for mining and extraction, (thermal) in-situ recovery and upgrading operations, as well as for the production of hydrogen. Depending on the recovery process, up to 25% of the energy content of the SCO is used in the form of natural gas. 

Furthermore, the extraction of non-conventional oil has other detrimental environmental impacts, such as water pollution and loss of biodiversity. Depending on the depth of the deposits, oil sands are either strip mined in open pits or heated so that the bitumen from which the non-conventional oil is extracted can flow to the surface (in-situ extraction). Both forms of oil-sands extraction require considerable amounts of energy (i.e., natural gas) and water, and lead to significant detrimental environmental impacts (Woynillowicz et al., 2005 see also Chapter 3). 

Tar Sands Canadian tar sands either are strip-mined and extracted with hot water or employ steam-assisted gravity drainage (SAGD) for in situ recovery of heavy oil (bitumen). The bitumen is processed into naphtha, kerosine, and gasoline fractions (which are hydrotreated), in addition to gas (which is recovered). Current production of syncrude from Canadian tar sands is about 113,000 T/d (790,000 B/d) with expected increases to about 190,000 T/d (1.7 MB/d) by 2010. 

A linear correlation is obtained between bitumen extraction with the paddle mill and the adhesion tension against water saturated pyrophyllite. That the degree of water saturation of the pyrophyllite is important in explaining the difference between the 2 extraction processes indicates that it will be necessary to study each process in terms of the relevant adhesion tensions. These results demonstrate that adhesion tension is the most important parameter found to date in determining the degree of separation in the presence of surfactants. Measurements of adhesion tension between surfactant solutions and minerals similar to those found in tar sand may be of considerable value in studies of surfactant utility in both aqueous-surfactant, solvent-aqueous-surfactant and in situ extraction processes. In addition, if appropriate model situations can be developed, measurements of adhesion tension may be useful in upgrading bitumen-water-clay emulsions obtained by a variety of in situ and heavy oil recovery processes. 

Canadian oil sand processing plants have been developed by Syncrude and Suncor for extraction and upgrading of tar sand bitumen into fuel. Aboveground surface mining and in-situ methods have been developed to recover raw material. Bitumen recovery from surface mined oil sand requires conditioning in order to free the bitumen from the sand matrix. 

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