Flood methods

Eig. 3. This polymer flooding method requites a preflush to condition the reservoir, the injection of a polymer solution for mobihty control to niinimi2e... 

One more variation to the many methods proposed for sulfur extraction is the fire-flood method. It is a modem version of the Sickian method, by which a portion of the sulfur is burned to melt the remainder. It would be done in situ and is said to offer cost advantages, to work in almost any type of zone formation, and to produce better sweep efficiency than other systems. The recovery stream would be about 20 wt % sulfur as SO2 and 80 wt % elemental sulfur. The method was laboratory-tested in the late 1960s and patents were issued. However, it was not commercially exploited because sulfur prices dropped. 

Induced reactions, 102 Induction period, 72 Inhibitor competitive, 92 noncompetitive, 93 Initial rates, method of, 8, 32 from power series, 8 Initiation step, 182 Inverse dependences, 130-131 Isokinetic relationship, 164—165 Isokinetic temperature, 163, 238 Isolation, method of (see Flooding, method of)... 

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. 

To develop improved alkali-surfactant flooding methods, several different injection strategies were tested for recovering heavy oils. Oil recovery was compared for four different injection strategies [641] ... 

The state of the art in chemical oil recovery has been reviewed [1732]. More than two thirds of the original oil remains unrecovered in an oil reservoir after primary and secondary recovery methods have been exhausted. Many chemically based oil-recovery methods have been proposed and tested in the laboratory and field. Indeed, chemical oil-recovery methods offer a real challenge in view of their success in the laboratory and lack of success in the field. The problem lies in the inadequacy of laboratory experiments and the limited knowledge of reservoir characteristics. Field test performances of polymer, alkaline, and micellar flooding methods have been examined for nearly 50 field tests. The oil-recovery performance of micellar floods is the highest, followed by polymer floods. Alkaline floods have been largely unsuccessful. The reasons underlying success or failure are examined in the literature [1732]. 

The quantification of the formulation of SOW systems was studied in detail during the 1970 s when a considerable research drive was dedicated to enhanced oil recovery by surfactant flooding methods [2], The basic concepts came from Winsor s work on the phase behavior of SOW systems and its R ratio of interactions between the surfactant molecules adsorbed at interface and oil and water [3], which has been presented thoroughly in a review book [4]. 

Shelton, J.L. and Schneider, F.N. The Effects of Water Injection on Miscible Flooding Methods Using Hydrocarbons and Carbon Dioxide, SPEJ. June 1975, 217-26... 

Field Application. Field trials of classical alkaline flooding have been disappointing. Mayer et al. (60) indicated that only 2 of 12 projects had significant incremental oil recovery North Ward Estes and Whittier with 6-8 and 5-7% pore volume, respectively. Estimated recovery from the Wilmington field was 14% with a classical alkaline flooding method (61). However, post-project evaluation of that field indicated no improvement over water-flooding (62). 

Sieve Ttay Flooding Method Seclicn Property Mode ... 

As the presence of multivalent salts normally results in flocculation of the polymers used in chemical-assisted EOR, the introduction of a monovalent alkaline solution has been employed. As a separate downstream slug, alkaline solutions are normally used as sacrificial materials to obtain synergistic effects with surfactant and polymer flooding methods. Alkaline materials that... 

Hence, on the basis of the generalized solvosystem concept it is possible to formulate the main distinctive features of different kinds of high-temperature ionic melts as media for acid-base interactions by the Lux-Flood method. 

The emulsion behaviour in porous media is discussed in [235]. O/w emulsions with volume fractions of up to 50% show Newtonian behaviour, whereas those with more than 50% are non-Newtonian liquids, the apparent viscosity of which depends on the shear rate. The viscosities of such emulsions are more than 20 times that of water and sometimes can be even comparable with that of oil. When the emulsion is moving, a temporary permeability reduction of the reservoir may occur due to the capture of small droplets by the surface of the porous medium. In this case, stable o/w emulsions may flow not as a continuous liquid, i.e. the emulsion flow largely depends on the nature of the porous medium. Therefore, it is necessary to know about the structure and physicochemical characteristics of the oil reservoir (porous medium) porosity, the mean pore diameter, the mean pore size and pore size distribution, chemical composition of the minerals ( acidic , basic , neutral ), the nature of the pore surface, first of all wettability, for a successful application of the emulsion flooding method. 

Continuous injection of steam results not only in higher oil yield but also creates a hydrodynamic connecdon between the injection well, on one hand, and the production wells, on the other. Moreover, a number of problems often typically develop during application of steam flooding method ... 

In view of this work, we feel that an effort is warranted for choosing a surfactant (e.g. anionic, cationic or nonionic) or cosurfactant that is capable of preventing asphaltene precipitation problems and the subsequent permeability reductions during tertiary oil recovery by chemical flooding methods (29). 

For example, major problems occur in gas flooding methods due to the displacing agent s high mobility and low density compared with those of... 

Recently, Taber and co-workers [65] have published screening criteria for all enhanced oil recovery (EOR) methods and their applications and impact of oil prices. About 3% of the worldwide production now comes from EOR. There are relatively few chemical flooding projects in the world, and these projects contribute very little to worldwide EOR production when compared to steamflooding and gas injection. A LTPWF, as a secondary flood method, may drain the reservoir to a residual oil saturation in the range of 15-20% rather fast and this may have an impact on the economics of the process. Future researeh on chemical flooding should move in this direction. 

Fred Wassmuth graduated from the University of Calgary with a Ph.D. in physical chemistry in 1990. Fred s work on chemically improved oil recovery processes started in 1991 at the Petroleum Recovery Institute, now a legacy company of the Alberta Research Council. He has been involved with traditional chemical flooding methods such as polymer, alkah/surfactant/ polymer and micellar surfactant floods for recovering conventional oils. This research led to several field projects which demonstrated the commercial apphcation of polymer flooding to improve the recovery of heavy oils in Western Canada. 

TRIBUCIDE may be applied by the vacuum, immersion, brush or flooding methods. 

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