Permeability from acid injection

Figure 8, from reference [14], shows the permeability ratio as a function of the acid injection rate. For brine saturated cores, the final core permeability exponentially increases with the acid injection rate. The same trend is noted in the case of oil saturated cores. 

The release of steroids such as progesterone from films of PCL and its copolymers with lactic acid has been shown to be rapid (Fig. 10) and to exhibit the expected (time)l/2 kinetics when corrected for the contribution of an aqueous boundary layer (68). The kinetics were consistent with phase separation of the steroid in the polymer and a Fickian diffusion process. The release rates, reflecting the permeability coefficient, depended on the method of film preparation and were greater with compression molded films than solution cast films. In vivo release rates from films implanted in rabbits was very rapid, being essentially identical to the rate of excretion of a bolus injection of progesterone, i. e., the rate of excretion rather than the rate of release from the polymer was rate determining. 

Properly designed, the injected acid enters the flow channels of the formation and flows radially outward from the wellbore dissolving mineral fine particles in the flow channels. Minerals forming the flow channel walls also react with the acids. These processes increase formation permeability near the wellbore. The end result... 

Injecting acid in such an interval produces wormholes in the nearwellbore region, which is damaged, so that the acid flow only takes place in the clean primary porosity of the rock. This superposes to the original step function of the permeability profile a second, similar function, stating that the acidized profile now includes in the vicinity of the wellbore, from rw up to re, a zone of infinite conductivity... 

Effect of the extracts on the increased vascular permeability induced by acetic acid in mice was determined according to Whittle method with some modifications [5]. Each test sample was administered orally to a group of ten mice, which were male Swiss albino mice (20-25 g) were purchased from the animal breeding laboratories of Refik Saydam Central Institute of Health (Ankara, Turkey), in 0.2 mF20 g body weight. Thirty minutes after the administration each mice was injected with 0.1 ml of 4% Evans blue (Sigma, St. Louis, Missouri, USA) in saline solution (/.v.) at the... 

The first step in protein metabolism in muscle is the uptake of amino acids from the blood by the fibers, via the extracellular space. Experiments with injected amino acids and with isolated muscle preparations by many workers have demonstrated that muscle fibers can accumulate amino acids from the medium. Experiments with a-aminoisobutyric acid, a nonmetabolizable amino acid, have been particularly useful in enabling accumulation to be studied independently of incorporation of the amino acid into protein. An increased accumulation of amino acids has been observed in the dystrophic mouse (B3), in vitamin E deficiency (D4), and in denervated muscle (D4). The authors of the last-mentioned observation concluded from their evidence that the increased accumulation was associated with increased active transport into the muscle cells, not with a change in passive permeability of the membranes. Nichoalds et al. (Nl) found that puromycin, which abolished protein synthesis, had no effect upon the accumulation of glycine- C by control or vitamin E-deficient muscle. More recently, Goldberg and Goodman (G4) observed a decrease in the accumulation of a-aminoisobutyric acid by soleus and plantaris muscles within 3 hours of denervation subsequently. 

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