Oil recovery processes

Lubricants, Fuels, and Petroleum. The adipate and azelate diesters of through alcohols, as weU as those of tridecyl alcohol, are used as synthetic lubricants, hydrauHc fluids, and brake fluids. Phosphate esters are utilized as industrial and aviation functional fluids and to a smaH extent as additives in other lubricants. A number of alcohols, particularly the Cg materials, are employed to produce zinc dialkyldithiophosphates as lubricant antiwear additives. A smaH amount is used to make viscosity index improvers for lubricating oils. 2-Ethylhexyl nitrate [24247-96-7] serves as a cetane improver for diesel fuels and hexanol is used as an additive to fuel oil or other fuels (57). Various enhanced oil recovery processes utilize formulations containing hexanol or heptanol to displace oil from underground reservoirs (58) the alcohols and derivatives are also used as defoamers in oil production. 

The focus of more recent work has been the use of relatively low concentrations of additives in other oil recovery processes. Of particular interest is the use of surfactants (qv) as CO2 (4) and steam mobiUty control agents (foam). Combinations of older EOR processes such as surfactant-enhanced alkaline flooding and alkaline—surfactant—polymer flooding show promise of improved cost effectiveness. 

Oil recovery from underground reservoirs can be improved by injection of water and pressing of oil to the surface. This secondary oil recovery process is relatively cheap though not always successful. Further, however more expensive, methods are the so-called tertiary oil recovery processes whereby the viscosity of the oil is lowered by mixing with low viscous oils or gas, or by temperature increase due to injection of steam, and where the viscosity of the pressing water layer is increased or the surface tension between water and oil is decreased via addition of surfactants. 

Brief details are given of an oil recovery process currently being researehed at the Institute for Mining and Materials Researeh, Kentueky University. The researeh project is part of a larger programme carried out by a 5 university. Dept, of Energy funded project. In this process oil is... 

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 physical properties of hydrogen peroxide indicate that hydrogen peroxide injection has the potential of combining the more favorable aspects of many enhanced oil-recovery processes, namely ... 

Associative copolymers of acrylamide with N-alkylacrylamides, terpoly-mers of acrylamide, N-decylacrylamide, and sodium-2-acrylamido-2-methyl-propane sulfonate (NaAMPS), sodium acrylate (NaA), or sodium-3-acrylamido-3-methylbutanoate (NaAMB) have been shown to possess the required rheologic behavior to be suitable for enhanced oil-recovery processes [1184]. 

Pseudozan is an exopolysacchaiide produced by a Pseudomonas species. It has high viscosities at low concentrations in formation brines, forms stable solutions over a wide pH range, and is relatively stable at temperatures up to 65° C. The polymer is not shear degradable and has pseudoplastic behavior. The polymer has been proposed for enhanced oil-recovery processes for mobility control [1075]. 

Xanthan exhibits an interaction with anionic surfactants (petroleum sulfate), which is a beneficial synergistic effect for mobility control in chemical-enhanced oil-recovery processes [1115]. 

The wettability of the rock is responsible for the behavior of a reservoir subjected to any oil-recovery process. Because the chemical composition of the mineral surface is mostly responsible for its wetting behavior, the relationship between wettability and chemical composition of the surface is key information. 

During improved oil-recovery processes, waterflooding of the oil is applied. The entrained water forms a water-in-oil emulsion with the oil. In addition, salts such as sodium chloride, calcium chloride, and magnesium chloride may be dissolved in the emulsified water. 

Optionally, the pH of the aqueous phase of the broken emulsion, after doing the job, can be adjusted to become alkaline. The salts of the polymers are converted into inactive species and the aqueous phase of the broken emulsion can be reinjected into ahydrocarbon-containing formation to recover additional hydrocarbons or bitumen [1187] as an improved oil-recovery process. 

J. A. Cruze and D. O. Hitzman. Microbial field sampling techniques for MEOR (microbial enhanced oil recovery) processes. US DOE Fossil-energy RepNIPER-351 CONF-870858, September 1987. 

Ryles, R.G. "Chemical Stability Limits of Water-Soluble Polymers Used in Oil Recovery Processes," SPE Paper 13585, 1985 International Symposium on Oilfield and Geothermal Chemistry, Phoenix, April 9-11. 

The strong interaction of polyvalent cations with polyions is well known to strongly alter the rheological properties of hydrolyzed polyacrylamide used in the tertiairy oil recovery process (1-4). The influence of divalent cations have already been studied(5-7) but the role played by the presence of small quantities of aluminium ions has never been investigated. 

Enhanced oil recovery processes involving displacing fluids such as dense C02 and liquified petroleum gases (LPG) are currently being applied in different parts of the world. At moderately high pressure and reasonable temperatures common in many reservoirs,... 

In Chapter 1, Microbial Enhanced Oil Recovery (MEOR) was defined as the use of microbes in the oil wells, in situ to enhance production of oil and prolong their active life cycle. Most conventional oil recovery processes are able to retrieve only, approximately 50% of the oil at the well. Theoretically, microbes are supposed to act by either ... 

Asphalt chemicals, ethyleneamines application, 8 500t, 506 Asphalt emulsifier amine oxides, 2 473 fatty acid amides, 2 458 Asphalt emulsions, 10 131 Asphaltenes, in petroleum vacuum residua, 18 589-590 Asphyxiants, 21 836 Aspirating aerators, 26 165-169 compressed, 26 168-169 propeller driven, 26 168 submersible, 26 169, 170t subsurface, 26 168 Aspiratory, 11 236-237 Aspirin, 4 103-104, 104t, 701 22 17-21. See also Acetylsalicylic acid as trade name, 22 19 for cancer prevention, 2 826 Aspirin resistance, 4 104 ASP oil recovery process, 23 532-533 Assay format, competitive, 14 142 Assay limits, in Investigational New Drug Applications, 18 692 Assays, for silver, 22 650. See also... 

Like most separation processes in the refinery, the process water used in coker fractionators (as is also the case in other product fractionators) often comes in direct contact with oil and can have a high oil content (much of that oil can be recovered through wastewater oil recovery processes). Thus, the main constituents... 

Several years ago during the "oil shortage", when serious efforts to resolve the complexities of applying enhanced oil recovery processes were being made, a crude oil sample recovered from Chevron s Wash basin in Utah was... 

When this pressure drops, it can be built-up again by water flooding. Unfortunately, after these primary and secondary processes, there still remains up to 70% of the oil adsorbed on the porous clays. Consequently, in recent years, there have been tremendous efforts made to develop tertiary oil recovery processes, namely carbon dioxide injection, steam flooding, surfactant flooding and the use of microemulsions. In this latter technique, illustrated in Fig. 1, the aim is to dissolve the oil into the microemulsion, then to displace this slug with a polymer solution, used for mobility control, and finally to recover the oil by water injection ( 1). 

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. 

Reaction conditions of this process were very mild compared to other waste oil recovery processes. 

Fifty years have elapsed since the first major surge occurred in the development of the Athabasca oil sands. The main effort has been devoted to the development of the hot water extraction process 13 significant projects utilizing this process are reviewed in this paper. However, many other techniques have also been extensively tested. These are classified into several basic concepts, and the mechanism underlying each is briefly described. A critical review of K. A. Claries theories concerning the flotation of bitumen is presented, and his theories are updated to accommodate the different mechanisms of the primary and secondary oil recovery processes. The relative merits of the mining and in situ approaches are discussed, and an estimate is made of the probable extent of the oil sand development toward the end of this century. 

Example. It may happen that an emulsion that is desirable in one part of the oil production process may be undesirable at the next stage. For example, in the oilfields, an in situ emulsion that is purposely created in a reservoir as part of an oil recovery process may change to a different, undesirable type of emulsion (water dispersed in oil) when produced at the wellhead. This emulsion may have to be broken and reformulated as a new emulsion suitable for transportation by pipeline to a refinery. Here, the new emulsion will have to be broken and water from the emulsion removed, which otherwise would cause processing problems in the refining process. 

Foams may contain not just gas and liquid (and usually surfactant), but also dispersed oil droplets and/or solid particles. Figure 1.5 shows a practical aqueous foam that contains dispersed oil droplets within the foam lamellae. This can occur, for example, when a foaming solution is used for detergent action in a cleaning process (see Section 12.2) or when a foam is propagated through an underground oil reservoir as part of an enhanced oil recovery process (See Section 11.2.2). 

Emulsions may be encountered throughout all stages of the process industries. For example, in the petroleum industry (see Chapter 11) both desirable and undesirable emulsions permeate the entire production cycle, including emulsion drilling fluid, injected or in situ emulsions used in enhanced oil-recovery processes, wellhead production emulsions, pipeline transportation emulsions, and refinery process emulsions [2], Such emulsions may contain not just oil and water, but also solid particles and even gas, as occur in the large Canadian oil sands mining and processing operations [2-4],... 

Foams, in the form of froths, are intimately involved and critical to the success of many mineral-separation processes (Chapter 10). Foams may also be applied or encountered at all stages in the petroleum recovery and processing industry (oil-well drilling, reservoir injection, oil-well production and process-plant foams). A class of enhanced oil recovery process involves injecting a gas in the form of a foam. Suitable foams can be formulated for injection with air/nitrogen, natural gas, carbon dioxide, or steam [3,5]. In a thermal process, when a steam foam contacts residual crude oil, there is a tendency to condense and create W/O emulsions. Or, in a non-thermal process, the foam may emulsify the oil itself (now as an O/W emulsion) which is then drawn up into the foam structure the oil droplets eventually penetrate the lamella surfaces, destroying the foam [3], See Chapter 11. 

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