Dissolved solids, produced water types

Surfactant Mixing Rules. The petroleum soaps produced in alkaline flooding have an extremely low optimal salinity. For instance, most acidic crude oils will have optimal phase behavior at a sodium hydroxide concentration of approximately 0.05 wt% in distilled water. At that concentration (about pH 12) essentially all of the acidic components in the oil have reacted, and type HI phase behavior occurs. An increase in sodium hydroxide concentration increases the ionic strength and is equivalent to an increase in salinity because more petroleum soap is not produced. As salinity increases, the petroleum soaps become much less soluble in the aqueous phase than in the oil phase, and a shift to over-optimum or type H(+) behavior occurs. The water in most oil reservoirs contains significant quantities of dissolved solids, resulting in increased IFT. Interfacial tension is also increased because high concentrations of alkali are required to counter the effect of losses due to alkali-rock interactions. 

Produced waters contain dissolved solids, but the amoimt varies from less than 100 to over 300,000 mg/1, depending on the geographical location as well as the age and type of reservoir. In general, water produced with gas is condensed water vapor with few dissolved solids and will be fresh with a very low salinity. Aquifer water produced with gas or oil will be much higher in dissolved sohds. A relationship exists between the reservoir temperature (which is related to subsurface depth) and the amoimt of total dissolved solids (TDS). Produced water from hot reservoirs tends to have higher TDS concentrations while cooler reservoirs tend to have lower levels of TDS. 

A similar technique has been applied to the generation of monodisperse suspensions in water. This type of method was first used in medical field and then widely used to spray monodisperse solid particles such as polystyrene latex particles. Aerosols of solutes have also been produced by atomizing solutions of salt, sugar or methylene blue dye dissolved in water. In practical operations, a low concentration of solid particles in a solvent is recommended in order to avoid possible agglomeration of suspensions in the solvent. 

A second type of salt that produces an acidic solution is one that contains a highly charged metal ion. For example, when solid aluminum chloride (AICI3) is dissolved in water, the resulting solution is significantly acidic. Although the Al3+ ion is not itself a Bronsted-Lowry acid, the hydrated ion A1(H20)63+ formed in water is a weak acid ... 

The next step in method development is the solubilization of the sample. The first solvent that is always tried is distilled/or deionized water, although the type of solvent is determined by the analytical method that has been chosen. There are some solid substances that must first be desegregated. They cannot be dissolved in any other way in any of the solvents. The best quality and reliability can be obtained in this step by utilization of a micro-wave digestion system.332 This system of desegregation produces the minimum contamination of the sample. Usually, the solvents and reagents used for desegregation of solids also constitute the blank for the analysis. 

As the discussion above implies, there are several different types of enzymatic attack on solid polymers. The simplest case in concept is attack on the polymer by a soluble, freely diffusing, extracellular enzyme which degrades the polymer to form water soluble, low molecular weight fragments that dissolve and diffuse through the aqueous environment until they are taken up by the microorganisms that produced and secreted the depolymerase enzyme. A more complex case is that in which the enzyme is associated with or bound to the outer wall or cell surface of the microorganism, which must attach itself to the polymer surface to permit the immobilized enzyme to seek out the section of the polymer... 

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