Acidizing fluids

Access of oxygen to steel surfaces during corrosion influences the wastage process in nonoxidizing acids. Fluid velocity can influence the amount of oxygen reaching the metal surface and, therefore, the corrosion rate. In deaerated acid solutions, steel corrosion rate is constant with fluid velocity. If dissolved oxygen is present, however, the corrosion rate is proportional to fluid velocity. 

Figure 7.9 Network of shallow ditches caused by condensation of acidic fluids during acid cleaning of a copper condenser tube.

Natural mobilization includes chemical, mechanical, and biological weathering and volcanic activity. In chemical weathering, the elements are altered to forms that are more easily transported. For example, when basic rocks are neutralized by acidic fluids (such as rainwater acidified by absorption of CO2), the minerals contained in the rocks can dissolve, releasing metals to aqueous solution. Several examples are listed below of chemical reactions that involve atmospheric gases and that lead to the mobilization of metals ... 

This mechanism as a main cause for epithermal-type Au deposition is supported by sulfur isotopic data on sulfides. Shikazono and Shimazaki (1985) determined sulfur isotopic compositions of sulfide minerals from the Zn-Pb and Au-Ag veins of the Yatani deposits which occur in the Green tuff region. The values for Zn-Pb veins and Au-Ag veins are ca. +0.5%o to -f4.5%o and ca. -l-3%o to - -6%c, respectively (Fig. 1.126). This difference in of Zn-Pb veins and Au-Ag veins is difficult to explain by the equilibrium isotopic fractionation between aqueous reduced sulfur species and oxidized sulfur species at the site of ore deposition. The non-equilibrium rapid mixing of H2S-rich fluid (deep fluid) with SO -rich acid fluid (shallow fluid) is the most likely process for the cause of this difference (Fig. 1.127). This fluids mixing can also explain the higher oxidation state of Au-Ag ore fluid and lower oxidation state of Zn-Pb ore fluid. Deposition of gold occurs by this mechanism but not by oxidation of H2S-rich fluid. 

In stimulation fluids containing concentrated HCl, the partial substitution of water by alcohols such as methanol, ethanol, and glycerol increases the corrosivity of the acid fluids and reduces the efficiency of the corrosion inhibitors [1148]. This effect is especially important for fatty amine-based inhibitors. For products containing acetylenic-type inhibitors the detrimental effect is less important and a weight loss may be maintained within acceptable limits using slightly higher, but still reasonable, levels of inhibitor. 

It was discovered that viscosifying the acid showed a remarkable improvement in acid fluid loss control. The enhancement was most pronounced in very-low-permeability limestone cores. The nature of the viscosifying agent also influenced the success. Polymeric materials were more effective than surfactant-type viscosifiers [682]. 

R. D. Gdansk . Huid properties and particle size requirements for effective acid fluid-loss control. In Proceedings Volume, pages 81-94. SPE Rocky Mountain Reg Mtg/Low Permeability Reservoirs Symp (Denver, CO, 4/26-4/28), 1993. 

The pancreatic juice is released through the ampulla of Vater into the duodenum to aid in the digestive process as well as buffer acidic fluid released from the stomach (Fig. 20-1). The pancreas contains a trypsin inhibitor to prevent autolysis. 

The various fields of chemistry play an important role in the discovery and exploitation of oil and gas reserves. Improved drilling and well completion fluids, cement slurries, hydraulic fracturing and acidizing fluids to improve well productivity, various chemical additives to be used in these fluids, and chemicals for enhanced oil recovery are essential to the improvement of production economics and to an increase in recoverable hydrocarbon reserves. Chemistry will become increasingly important in future hydrocarbon production with the decreased likelihood of major onshore discoveries, increased discovery and production costs associated with deep offshore wells and Arctic frontier provinces, and the decline in drilling since early 1982. 

A corrosion inhibitor was present in all acid fluids. Eight of the well treatments incorporated a cationic organic polymer mineral fines stabilizer in the first three treatment stages. The active polymer concentration was less than the reported aqueous polymer concentration of one percent (by volume). Again, this was because the polymer was not supplied as a 100% active product. 

Watkins, D.R. and Roberts, G.E. "On-Site Acidizing Fluid Analysis Shows HCl and HF Contents Often Varied Substantially From Specified Amounts," J. Pet. Technol.. May 1983, 865-871. Hartley, R. and Bosma, M.G.R. "Fracturing in Chalk Completions," J. Pet. Technol.. January 1985, 73 79. 

For simplicity, we do not allow supersaturated minerals to precipitate. The result is an acidic fluid in which A10H++ and Al(OH) " predominate among aluminum species. 

It was also observed that acid fluids seem to be restricted to the Banyu Pahit... 

First, consider the effect of pH-increase due to the reaction of an acidic fluid with a carbonate-bearing host rocks. At pH = 5, practically all of the dissolved sulfur is undissociated H2S, whereas at pH = 9 the dissolved sulfide is almost entirely dissociated. Since H2S concentrates " S relative to dissolved sulfide ion, an increase in pH leads directly to an increase in the 5 " S of precipitated sulfides. 

Hermoso, D. Z., Mejorada, A. V. Rae, A. J. 1998. Determination of the nature of acidic fluids in the Palinpinon geothermal field, Philippines through the use of 534S in sulphates and sulphides. In Proceedings I9th Annual PNOC-EDC Geothermal Conference, 65-75. 

Rubber degradation in the sealing system occurs when in contact with high pH (basic) and low pH (acidic) fluids in the systems. 

Acid-in-oil emulsion can extend the propagation of acid considerable distances into a reservoir because the continuous (oil) phase prevents or minimizes contact between the acid and the rock [4,678,689]. Emulsification also increases viscosity and will improve the distribution of the acid in layered and heterogeneous reservoirs. Acidizing foams are aqueous, in which the continuous phase is usually hydrochloric acid (carbonate reservoirs) or hydrofluoric acid (sandstone reservoirs), or a blend, together with suitable surfactants and other stabilizers [345,659]. Foaming an acidizing fluid increases its effective viscosity, providing mobility control when it is injected [678]. 

J. Krissmann, M. A. Siddiqi, K. Lucas, Absorption of sulfur dioxide in dilute aqueous solutions of sulfuric and hydrochloric acid, Fluid Phase Equilibriums, 1997, 141, S221-S233. 

Although deprived of secreting glandules, the vaginal mucosa is covered with a watery acidic fluid. This fluid includes contributions from vaginal transudation, Bartholin and Skene glands, exfoliated epithelial cells, residual urine, and fluids from... 

Fig. 83. Stability of grunerite in water-carbonic acid fluids (equilibrium Sid -I- Q -I- Gru). a. Isobars figures on curves designate P( = + A o,- Isotherms, figures on curves designate T C (Mel nik and...

Fig. 93. Equilibrium of magnesian-iron minerals in rocks with excess silica. A. In silicate iron-formations (aqueous fluid. Cum + Px -t- OH- Q association). B. In carbonate iron-rich rocks (carbonic acid fluid. Car -(- Px -I- 01 -t- Q association). Figures indicate maximum iron content of orthopyroxene in association with quartz and olivine.

The adverse effects of peritoneal dialysis fluids on the peritoneum have been succinctly summarized by authors arguing the case for a new, less toxic, and less acidic fluid for peritoneal dialysis (7). A low pH, high osmolality and lactate concentration, and the presence of several toxic contaminants may all contribute to impaired cellular function in the peritoneal membrane. In conventional peritoneal dialysis pH is dehberately lowered to 5.0-5.6... 

Rippe B, Simonsen O, Wieslander A, Landgren C. Clinical and physiological effects of a new, less toxic and less acidic fluid for peritoneal dialysis. Perit Dial Int I997 I7(I) 27-34. 

Asphalt has been used as a major component in many coating formulations. These include epoxy-asphalts (much used in refineries) and urethane-asphalts. Of these the urethane-asphalts, some of which are true copolymers, are the most satisfactory substitutes for hot asphalt. They can be used at exposures higher in temperature than can hot asphalt due to their freedom from cold flow, and are reasonably good barriers. Like the asphalt emulsions and solvent putties, however, they can be penetrated, though at a much slower rate, by small molecule acids. Fluid (cold) applied membranes are discussed elsewhere in this volume. 

Consider an abandoned subsurface deposit rich in pyrite and ore minerals (e.g., PbS, ZnS, CuFeS2, FeAsS, etc.) and located close to, or below, the water table. Surface-derived, oxygenated water will oxidize the deposit, releasing Fe-rich, sulfate solutions, becoming oxygen-depleted in the process. If acidic fluids traveling outward from the... 

The time for a medication to disintegrate and dissolve is called the rate limiting time. Table 2.1 shows the rate-limiting time for medication forms. Rate limiting time is higher if the medication is in acidic fluids rather than alkaline fluids. 

Blacklock,T. J. Shuman, R. F. Butcher, J. W Shearin,W. E.,Jr. Budavari, J. Grenda,V., Synthesis of Semisynthetic Dipeptides Using N-Carboxyanhydrides and Chiral Induction on Raney Nickel. A Method Practical for Large Scale. J. Org. Chem. 1987, 53, 836 Pradhan, A. A. Vera, J. H., Effect of acids and bases on the solubility of amino acids. Fluid Phase Equilibria 1998, 152, 121. 

Digestive juice is the acidic fluid secreted by glands in the lining of the stomach. 

Put the oil of amber into a glass vessel, and gradually drop the acid into it, at the same time stirring the mixture with a glass rod. Let it stand for thirty-six hours, then separate the supernatant resinous matter from the acid fluid beneath, and wash it repeatedly, first with cold, and lastly with hot water, till the acid taste disappears. 

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