Enhanced Oil Recovery EOR

Enhanced oil recovery (EOR) techniques seek to produce oil which would not be recovered using the primary or secondary recovery methods discussed so far. Three categories of enhanced oil recovery exist ... 

Keywords production decline, economic decline, infill drilling, bypassed oil, attic/cellar oil, production potential, coiled tubing, formation damage, cross-flow, side-track, enhanced oil recovery (EOR), steam injection, in-situ combustion, water alternating gas (WAG), debottlenecking, produced water treatment, well intervention, intermittent production, satellite development, host facility, extended reach development, extended reach drilling. 

A considerable percentage (40% - 85%) of hydrocarbons are typically not recovered through primary drive mechanisms, or by common supplementary recovery methods such as water flood and gas injection. This is particularly true of oil fields. Part of the oil that remains after primary development is recoverable through enhanced oil recovery (EOR) methods and can potentially slow down the decline period. Unfortunately the cost per barrel of most EOR methods is considerably higher than the cost of conventional recovery techniques, so the application of EOR is generally much more sensitive to oil price. 

Microemulsions became well known from about 1975 to 1980 because of their use ia "micellar-polymer" enhanced oil recovery (EOR) (35). This technology exploits the ultralow iaterfacial tensions that exist among top, microemulsion, and bottom phases to remove large amounts of petroleum from porous rocks, that would be unrecoverable by conventional technologies (36,37). Siace about 1990, iaterest ia the use of this property of microemulsions has shifted to the recovery of chloriaated compounds and other iadustrial solveats from shallow aquifers. The latter appHcatioa (15) is sometimes called surfactant-enhanced aquifer remediation (SEAR). 

Enhanced oil recovery (EOR) processes (also called tertiary recovery processes) are used to recover a portion of the remaining two-thirds... 

I. Lazar, A. Voicu, G. Archir, T. Toma, I. G. Lazar, L. Blanck, and V. Constantin. Investigations on a new Romanian biopolymer (pseu-dozan) for use in enhanced oil recovery (EOR). In Proceedings Volume, volume 2, pages 357-364. Minerals, Metals Mater Soc et al Biohydromet Technol Int Symp (Jackson Hole, WY, 8/22-8/25), 1993. 

This decline in the price of oil has resulted in major changes in the types of enhanced oil recovery (EOR) being studied in the laboratory and field tested. Steam injection and injection of miscible gases, primarily remain of great interest due to the... 

The oil price rises in the 1970s stimulated interest in Enhanced Oil Recovery (EOR), and fairly rapidly the biopolymer xanthan, the extracellular polysaccharide from the bacterium Xanthomonas campestris. an organism which normally resides on cabbage leaves, was identified as a leading contender as a viscosifier for polymer enhanced water flooding. 

Enhanced oil recovery (EOR), 9 1 12 23 18 611-639. See also EOR polymers additional technologies in, 18 630-631 alkaline flooding in, 18 629-630 carbon dioxide capture and storage, 18 617... 

Micellar flooding, 13 628 Micellar-polymer (MP) chemical enhanced oil recovery systems, 23 531 Micellar-polymer enhanced oil recovery (EOR), 16 429... 

Petroleum, 3 683 13 570-611. See also Crude oil(s) Enhanced oil recovery (EOR) Oil entries Petroleum resources... 

The fundamental phases of petroleum production include (1) the initial exploration required to find heretofore undiscovered oil and gas reservoirs (2) primary and secondary recovery methods, which make use of both naturally occurring (or primary) reservoir energy and the application of secondary energy sources, such as the injection of gas or water and (3) enhanced oil recovery used to increase ultimate oil production beyond that achievable with primary and secondary methods. Enhanced oil recovery (EOR) methods increase the proportion of the reservoir by improving the sweep efficiency, reducing the amount of residual oil in the swept zones (increasing the displacement efficiency), and reducing the viscosity of thick oils. 

Enhanced oil recovery (EOR) methods increase ultimate oil production beyond that achievable with primary and secondary methods. This is accomplished by increasing the proportion of the reservoir affected. EOR methods arc of three broad groups (1) thermal, (2) miscible, and (3) chemical. 

In the mid-term, sequestration pilot testing will develop options for direct and indirect sequestration. The direct options involve the capture of C02 at the power plant before it enters the atmosphere coupled with "value-added" sequestration, such as using COz in enhanced oil recovery (EOR) operation and in methane production from deep unmineable coal seams. "Indirect" sequestration involves research on means of integrating fossil fuel production and use with terrestrial sequestration and enhanced ocean storage of carbon. 

In some cases, production from an oil or natural gas reservoir can be enhanced by pumping C02 gas into the reservoir to push out the product, which is called Enhanced Oil Recovery (EOR). The United States is the world leader in EOR technology, using about 32 million ton of C02 per year for this purpose. From the perspective of the sequestration program, EOR represents an opportunity to sequester carbon at low net cost, due to the revenues from recovered oil/gas. 

At the Weyburn oil fields in Saskatchewan, Canada, C02 captured at a coal-to-methane plant in North Dakota and piped across the border is being injected, with the joint objective of enhanced oil recovery (EOR) and C02 storage. 

An important and perspective application of foams is its use in petroleum and gas industries in drilling wells, in developing oil pools, in cleaning out wells from sand cork [142-148], in foam enhanced oil recovery (EOR) from underground formations [149-154]. 

Enhanced oil recovery (EOR) is a collective term for various methods of increasing oil recoveries that have been developed since about 1970. Up until about 1980, the use of surfactants in EOR was more or less synonymous with "micellar/polymer" flooding, in which surfactants are used to decrease the interfacial tension between "oil" and "water" from 10 dyne/cm to < 0.01 dyne/cm. 

Reservoir definition impacts on chemical enhanced oil recovery processes more than any other type of Enhanced Oil Recovery (EOR). This is because these processes are exceptionally prone to deterioration through mixing and through bypassing. Both mixing and bypassing relate directly to the spatial distribution of permeabilities which is the major topic of this paper. 

Foam exhibits higher apparent viscosity and lower mobility within permeable media than do its separate constituents.(1-3) This lower mobility can be attained by the presence of less than 0.1% surfactant in the aqueous fluid being injected.(4) The foaming properties of surfactants and other properties relevant to surfactant performance in enhanced oil recovery (EOR) processes are dependent upon surfactant chemical structure. Alcohol ethoxylates and alcohol ethoxylate derivatives were chosen to study techniques of relating surfactant performance parameters to chemical structure. These classes of surfactants have been evaluated as mobility control agents in laboratory studies (see references 5 and 6 and references therein). One member of this class of surfactants has been used in three field trials.(7-9) These particular surfactants have well defined structures and chemical structure variables can be assigned numerical values. Commercial products can be manufactured in relatively high purity. 

Despite the massive drop of oil prices in the early 1980s, the crippling or elimination of several major oil companies, and the layoffs of thousands of talented employees, the oil industiy has managed to commercialize a major new kind of enhanced oil recovery (EOR). This type of EOR is gas-flooding , in which COj (or less often, some other fluid) is injected into an old field at a pressure of about 8 MPa or greater to produce oil that otherwise would not be recovered. 

Enhanced oil recovery (EOR) using carbon dioxide expansion is the largest scale application of gas expanded liquids. EOR using carbon dioxide aids in the flushing out of oil reservoirs carbon dioxide is injected into the well and displaces the remaining oil. It has several advantages over water, which can also be used in this process. For example, it lowers the viscosity of the crude oil, it... 

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