Enhanced oil recovery technology

A chemical-enhanced oil-recovery technology can be used to remove oily contaminants from soil. Laboratory studies demonstrated that a variety of alkaline-surfactant combinations can be used with a polymer to reduce the residual oil saturation in waterflooding [1435]. 

M. J. Pitts, K. Wyatt, T. C. Sale, and K. R. Piontek. Utilization of chemical-enhanced oil recovery technology to remove hazardous oily waste from alluvium. In Proceedings Volume, pages 33-44. SPE Oilfield Chem Int Symp (New Orleans, LA, 3/2-3/5), 1993. 

Petroleum sulfonates have found wide usage in enhanced oil recovery technology. 

Enhanced oil recovery technology shouldbe considered early in the producing life of a reservoir. Maity of the processes depend on the establishment of an oil bank in order for the process to be snccessful. When oil saturations are high, the oil bank in easier to form. It is cmcial for engineers to understand the potential of EOR and the way EOR can be apphed to a particular reservoir. 

In spite of the above-mentioned difficulties, enhanced oil recovery technologies are appealing since indeed the... 

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). 

Other Specialty Chemicals. In fuel-ceU technology, nickel oxide cathodes have been demonstrated for the conversion of synthesis gas and the generation of electricity (199) (see Fuel cells). Nickel salts have been proposed as additions to water-flood tertiary cmde-oil recovery systems (see Petroleum, ENHANCED oil recovery). The salt forms nickel sulfide, which is an oxidation catalyst for H2S, and provides corrosion protection for downweU equipment. Sulfur-containing nickel complexes have been used to limit the oxidative deterioration of solvent-refined mineral oils (200). 

Pressure Swing Adsorption. A number of processes based on Pressure Swing Adsorption (PSA) technology have been used in the production of carbon dioxide. In one version of the PSA process, CO2 is separated from CH using a multibed adsorption process (41). In this process both CH4 and CO2 are produced. The process requires the use of five adsorber vessels. Processes of this type can be used for producing CO2 from natural gas weUs, landfiU gas, or from oil weUs undergoing CO2 flooding for enhanced oil recovery (see Adsorption, gas separation). 

Acrylamide—polymer/Ct(III)catboxylate gel technology has been developed and field tested in Wyoming s Big Horn Basin (211,212). These gels economically enhance oil recovery from wells that suffer fracture conformance problems. The Cr(III) gel technology was successful in both sandstone and carbonate formations, and was insensitive to H2S, high saline, and hard waters (212). 

Secondary recovery, infill drilling, various pumping techniques, and workover actions may still leave oil, sometimes the majority of the oil, in the reservoir. There are further applications of technology to extract the oil that can be utilized if the economics justifies them. These more elaborate procedures are called enhanced oil recovery. They fall into three general categories thermal recoveiy, chemical processes, and miscible methods. All involve injections of some substance into the reservoir. Thermal recovery methods inject steam or hot water m order to improve the mobility of the oil. They work best for heavy nils. In one version the production crew maintains steam or hot water injection continuously in order to displace the oil toward the production wells. In another version, called steam soak or huff and puff, the crew injects steam for a time into a production well and then lets it soak while the heat from the steam transfers to the resei voir. After a period of a week or more, the crew reopens the well and produces the heated oil. This sequence can be repeated as long as it is effective. 

FIGURE 6.6 Prospects for enhanced oil recovery using implemented and advanced technologies are shown above. 

Most of the increase in the estimate from applying advanced technology comes from improvements in chemical flooding methods. The projections assume that crude oil has a nominal price of 30 per barrel and that the minimum rate of return on capital is 10 percent. Reprinted with permission from Enhanced Oil Recovery. Copyright 1984 by the National Petroleum Council. 

Enhanced oil-recovery processes include chemical and gas floods, steam, combustion, and electric heating. Gas floods, including immiscible and miscible processes, are usually defined by injected fluids (carbon dioxide, flue gas, nitrogen, or hydrocarbon). Steam projects involve cyclic steam (huff and puff) or steam drive. Combustion technologies can be subdivided into those that autoignite and those that require a heat source at injectors [521]. 

The oil production from thin under-gas cap zones with an active aquifer is not efficient because of the rapid breakthrough of gas or water. The water-alternating gas technology based on the injection of water solution with oil-and water-soluble polymers seems to be promising to stimulate such wells. For heavy oils, this technology can be considered as an alternative to thermal-enhanced oil recovery [1673]. 

R. S. Bryant and T. E. Burchfield. Review of microbial technology for improving oil recovery. In Proceedings Volume. Nat Inst Petrol Energy Res Microbial Enhanced Oil Recovery Short Course (Bartlesville, OK, 5/23), 1989. 

K. A. Sandbeck and D. O. Hitzman. Biocompetitive exclusion technology a field system to control reservoir souring and increase production. In US DOE Rep, number CONF-9509173, pages 311-319. 5th US DOE et al Microbial Enhanced Oil Recovery Relat Biotechnol for Solving Environ Probl Int Conf (Dallas, TX, 9/11-9/14), 1995. 

Recent research and field tests have focused on the use of relatively low concentrations or volumes of chemicals as additives to other oil recovery processes. Of particular interest is the use of surfactants as CO (184) and steam mobility control agents (foam). Also combinations of older EOR processes such as surfactant enhanced alkaline flooding and alkaline-surfactant-polymer flooding have been the subjects of recent interest. Older technologies polymer flooding (185,186) and micellar flooding (187-189) have been the subject of recent reviews. In 1988 84 commercial products polymers, surfactants, and other additives, were listed as being marketed by 19 companies for various enhanced oil recovery applications (190). 

Enhanced Oil Recovery Group, U.S. Department of Energy, Morgantown Energy Technology Center, Morgantown, WV 26507—0880... 

Foam is a promising fluid for achieving mobility control in underground enhanced oil recovery (1-3). Widespread application of this technology to, for example, steam, CO, enriched... 

Microbes, Inc. founded in 1988, is a Delaware corporation, whose business includes two areas increasing yields from (1) oilfields and (2) food crops. The oil-related business entails the development and supply of microbial products and services for enhancing oil recovery from existing reservoirs. National Parakleen Company, Inc. is a subsidiary, which since 1988, have applied their proprietary technology in oil wells and reservoirs, jointly with Microbes, Inc. Their enhanced recovery technology (Migration Microbial... 

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... 

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