Emulsion injectable

Review of the literature resulted in several references relating to the use of emulsions as agents for causing permeability reduction. McAuliffe (2) demonstrated that injection of externally produced oil-in-water emulsions at 24 C effectively reduces the water permeabilities of sandstone cores. These laboratory findings were later substantiated by a field test of emulsion injection followed by waterflooding in the Midway-Sunset Field (3). 

Figures 8, 9, and 10 show the permeability reductions that resulted from injecting 0.5% emulsions produced from the Wilmington crude oil and caustic. The temperatures are, respectively, 25°, 90°, and 110°C. The reductions in permeability were from 84 to 88%, with most of the reduction occurring within 1 PV of emulsion injection.

Similar results were obtained when injecting an externally produced emulsion into a core which was subsequently steamflooded. The results (Table V) show that the reduction in permeability caused by the emulsion (created with Wilmington oil) was stable at steamflood conditions. This experiment was conducted with a 25-in. core and saturated steam at 160°C. Before emulsion injection. 

Temp. (°C) Emulsion Concentration %) Emulsion Injected (PV) Permeability Absolute Final Reduction (md) (md) (%) Flow rate (cc/min)... 

Emulsion Injection Into Cores Containing Residual Oil. These experiments were performed because of uncertainty about the effect of residual oil on an "emulsion block." In the case of residual oil remaining in the core, the effective permeability to water is much lower at the beginning of emulsion injection than with an oil-free core. The results for Delaware-Childers oil are summarized in Table VII. 

In one experiment, emulsion injection was begun after waterflood, and in the others emulsion injection was begun after tertiary recovery. The number of pore volumes of emulsion injected was 10, 7, and 8, respectively. The reductions in effective permeability, 52, 33, and 56%, were significant, but not as high as those when using oil-free cores. 

For the tests listed in Table VIII, the emulsions were injected after high-permeability cores were saturated with Wilmington oil and then steamflooded. In the first test, emulsion injection lowered the permeability by 91% however, subsequent injection of steam at 194°C resulted in destruction of most of that emulsion block. In... 

Soluble immunogens should be administered as Freund s emulsions, injected subcutaneously into the abdominal wall just on either side of the midline. The injection sites will usually ulcerate after a week or so, but the animals are apparently free from discomfort, thrive, and make good antibodies. 

Soo and Radke (11) also studied the effect of average droplet size of emulsion on the flow behavior in porous media. The droplet size distribution of the emulsions that were prepared with surfactants and NaOH in a blender are shown in Figure 12. These droplet size distributions were found to be log-normal distributions. Others (9, 27) have also observed that the size of emulsion droplets was log-normally distributed. Soo and Radke (11) conducted experiments with emulsions having different average mean diameter in fine Ottawa water-wet sand packs. Their results of the reduced permeability, k/ko, and reduced effluent volume concentration as a function of the pore volume of oil (in the emulsion) injected are shown in Figure 13. All emulsions were of 0.5% quality, and the initial permeability, ko, was 1170 mD (millidarcies). The lines in the figure represent results of flow theory (12,13) based on deep-bed filtration principles. 

Figure 16 shows the results when 20 pore volumes of an emulsion having a 3.1- xm mean droplet size is injected into an 1170-mD sand pack and is followed by several pore volumes of water (ii). After emulsion injection, a permeability reduction of about 50% is observed. With water injection, the effluent concentration drops to 0 after one pore volume, whereas the permeability is unaltered. For this dilute emulsion, the droplets are captured in the porous medium, and this capture leads to blocking of the flow paths. Figure 16 shows that once the droplets are captured, they do not re-enter the flow stream, velocity being constant. Soo and Radke (ii) proposed the following physical interpretation for the results of Figure 15. Initially oil droplets are preferentially captured in the small-size pores, and as injection proceeds, more and more of the small pores become blocked. This blockage leads to a flow diversion toward larger size pores, and the rate...

This observation was also made by McAuliffe (9), who injected a 0.5% OAV emulsion (3.8-(xm average droplet size) into a Boise sandstone core (1170 mD) and Alhambra core (520 mD). The results are shown in Figure 20 and depict that the permeability of the Alhambra core was reduced more rapidly earlier during the injection period than that of the Boise core. The percentage reduction in permeability after 10 pore volumes of emulsion injection, however, was the same for the two cores. After 10 pore volumes of the OAV emulsion, distilled water was injected into the two cores. Distilled water, however, does not remove the oil droplets that are captured in the... 

Figure 20. Reduction in water permeability by emulsion injection and residual effect of emulsion. Percentages at arrows compare fluid permeability at that point with original water permeabilities. (Reproduced with permission from reference 9. Copyright 1973 Society of Petroleum Engineers.)...

The model correctly describes the permeability reduction as a function of pore volume injected and takes into account the effect of emulsion droplet saturation and droplet-size to pore-size ratios. The main drawbacks of this theory are that the permeability reduction is caused as long as the emulsion is flowing and that the initial permeability is restored once the emulsion injection is followed by water alone. In other words, the emulsion droplets all pass through the porous medium, and none of them is captured inside. However, experimental evidence 9,11) suggests that the permeability reduction cannot be restored after subsequent water injection (Figure 16). 

Emulsion Injection for Recovery of Heavy Oil. Oil-in-water emulsions may be useful as sweep improvement agents in heavy-oil reservoirs. To improve the mobility ratio occurring with high-viscosity oils, McAuliffe (69) and Schmidt et al. (70) proposed the use of stable oil-inwater emulsions. These authors conducted laboratory experiments with emulsions prepared by reaction of sodium hydroxide with a synthetic acidic oil. The theoretical background for emulsion blocking has been discussed in Chapter 6, and it forms the basis for one of several mechanisms of caustic flooding (7i). These emulsions may form spontaneously during oil recovery processes (72), but can just as easily be prepared and injected as enhanced oil recovery fluids. 

Decker and Flock (74) investigated the application of emulsion injection for steam-flooding processes. In laboratory models, emulsions containing 5 vol% crude oil were effective in blocking channels created by steam injection during subsequent steam-injection cycles. Oil droplets in the emulsion were predominantly in the 1-2- xm range, but droplets as large as 10 fxm were observed. 

Pietrasik Z, Wang H, Janz JA. Effect of canola oil emulsion injection on processing characteristics and consumer acceptability of three muscles from mature beef. Meat Sci. 93(2) (2013) 322-328. 

N. P. Lenzo, L. J. Martins. B. C. Mortimer, and G. Redgrave. Effects of phospholipid composition on the metaboli.sm of triacylglycerol. cholesieryl esters and phosphatidylcholine from lipid emulsion injected intravenously in rats. Biochim. Bio-phy.s. Acta. 960 111-118, 1988. 

B. C. Mortimer. W. J. Simmonds. C. A. Joll. R. V. Stick, and T. G. Redgrave, The cfTccl of added monoacytglyccrols on the removal from plasm of chylomieron-likc emulsions injected intravenously in rats. Biochim. Biophys, Acta. 1002 359-.364,... 

R. J. Litz, T. Roessel, A. R. Heller and S. N. Stehr, Reversal of central nervous system and cardiac toxicity after local anesthetic intoxocation by lipid emulsion injection. Anesth. Analg., 106(5), 1575-1577 (2008). 

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