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...Subsystems consist of power supplies, insulators, electrodes, liquid distribution systems, instrumentation and...ther than by uniformly diminishing output. Short bursts of high-intensity energy are applied to the emulsion, and the duration of the pulses is limited to maintain an average power output within the rating of...ode array is momentarily discharged by an arc, and if the arcs occur frequently enough (as in a wet emulsion), the electrodes might be discharged long enough to allow slippage of process fluids that have not ...
Subsystems consist of power supplies, insulators, electrodes, liquid distribution systems, instrumentation and safety systems, solids removal systems, mixing devices, level controllers and gauges; as well as, water in oil detectors. Transformers used in dehydrator and desalter power supplies must be capable of sustaining a short-circuited output without damage or overheating. This protection normally is derived by including a saturable core reactor sized commensurately to the reactance of the transformer winding in series with the primary winding of the transformer. As the primary current increases, the voltage drop across the reactor increases; therefore, failures in the vessel electrical components or process upsets causing high conductivity will not damage the transformer. Transformers in this service also experience high mechanical stresses from rapidly fluctuating loads and must be constructed with cores and windings that are mechanically solid and highly resistant to vibration. A weakness of electrostatic coalescers has been their means of protecting the electrical system in the event of excessive power requirements during short-term upsets. Unfortunately, the reactor-based protection scheme described above effectively reduces power input to the vessel precisely when it is most needed. To counteract this, an electronic controller was developed that can sense the load demand and modify the power input to the transformer.
...An emulsion treating unit or system will use one or more of the methods listed in Table 1 to aid in destabilizing, coale...nd water. Crude oil emulsions with similar viscosity ranges do not always require the same type of treating equipment or the same ...treating temperature. Emulsions that are produced from different wells on the same lease or from the same fo...
An emulsion treating unit or system will use one or more of the methods listed in Table 1 to aid in destabilizing, coalescence, gravity separation. Heating oil emulsions has four basic benefits; It reduces viscosity, increases droplets, dissolves paraffin crystals, and increases density between oil and water. Crude oil emulsions with similar viscosity ranges do not always require the same type of treating equipment or the same treating temperature. Emulsions that are produced from different wells on the same lease or from the same formation in the same field might require different treating temperatures. For this reason, treating temperatures should be tested so that the lowest practical treating temperature for each emulsion and treating unit or system can be determined by trial.
...Standard emulsion treating procedures, equipment, and systems used during primary and secondary oil production might be inadeq...uate for treating the emulsions encountered in EOR projects. EOR methods of oil production might cause the production...ects usually are treated independently of the primary and secondary emulsions from the same fields. Emulsion-treating procedures, equipment, and systems have been and continue to be developed for use in these EOR proj...
Standard emulsion treating procedures, equipment, and systems used during primary and secondary oil production might be inadequate for treating the emulsions encountered in EOR projects. EOR methods of oil production might cause the production of emulsions that do not respond to treatment that normally is used in primary- and secondary-oil-production operations. The emulsions from EOR projects usually are treated independently of the primary and secondary emulsions from the same fields. Emulsion-treating procedures, equipment, and systems have been and continue to be developed for use in these EOR projects. Even though a normal water in oil emulsion exists in the oil production system, produced water that is separated from crude oil usually contains small quantities of oil.
...f emulsions: Eliminate production of water with oil where possible and practical. By studying the treating problem and selecting appropriate ...treating methods, equipment, and procedures. The ...emulsion treating system should be as small as possible, yet capable of adequately handling ...
...s a low fraction of water in the oil can reduce salt content. In that case, the terms desalting and emulsion treating effectively have the same meaning, and the concepts and equipment can be used. The required maximu...f a mixing device (in which fresh water is used to wash the crude oil) and any of the electrostatic treating systems described below (which then are used to dehydrate the oil to a low water content). Mixing d...em because of high pH, the presence of surfactants, and other conditions that can lead to increased emulsion stability. Obviously, to remove salt, the dilution water must have low enough salt content to a...
Most produced water contains salts that can cause problems in production and refining, when solids precipitate to form scale on process equipment. The salts also accelerate corrosion in piping and equipment. The salt content of crude oil almost always consists of salt dissolved in small droplets of water that are dispersed in the crude. Sometimes the produced oil contains crystalline salt, which forms because of pressure and temperature changes and because of stripping of water vapor as the fluid flows up the wellbore and through the production equipment. The salinity of produced brine varies widely, but for most produced water, it ranges from 5,000 to 250,000 ppm of equivalent NaCl.
...Demulsification is the breaking of a crude oil emulsion into oil and water phases. From a process point of view, the oil producer is interested in three as...rises from the formation of interfacial films that encapsulate the water droplets. To separate this emulsion into oil and water, the interfacial film must be destroyed and the droplets made to coalesce. There... interfacial film are discussed in Stability of oil emulsions. The factors that enhance or speed up emulsion breaking are discussed here. Application of heat promotes oil/water separation and accelerates the...
Demulsification is the breaking of a crude oil emulsion into oil and water phases. A fast rate of separation, a low value of residual water in the crude oil, and a low value of oil in the disposal water are obviously desirable. Produced oil generally has to meet company and pipeline specifications. For example, the oil shipped from wet-crude handling facilities must not contain more than 0.2% basic sediment and water (BS&W) and 10 pounds of salt per thousand barrels of crude oil. This standard depends on company and pipeline specifications. The salt is insoluble in oil and associated with residual water in the treated crude. Low BS&W and salt content is required to reduce corrosion and deposition of salts. The primary concern in refineries is to remove inorganic salts from the crude oil before they cause corrosion or other detrimental effects in refinery equipment. The salts are removed by washing or desalting the crude oil with relatively fresh water. Oilfield emulsions possess some kinetic stability. This stability arises from the formation of interfacial films that encapsulate the water droplets.
...Separating a crude-oil/water emulsion into its bulk phases of oil and water usually involves three basic steps: (Coagulation). Counterac...ting the stabilizing effect of the emulsifier destabilizes an emulsion. To increase the probability of coalescence of dispersed water droplets on contact, the tough skin ...complished by adding heat and/or a properly selected, interfacially active chemical compound to the emulsion. (This primarily is the task of the chemical treatment program.) (Flocculation). After the films t...
To increase the probability of coalescence of dispersed water droplets on contact, the tough skin or film surrounding the dispersed water droplets must be weakened and broken. This usually is accomplished by adding heat and/or a properly selected, interfacially active chemical compound to the emulsion. After the films that encase the dispersed droplets have been broken or sufficiently weakened, the droplets must coalesce into drops that are large enough to settle out of the continuous phase of oil. The rate of contact of dispersed water droplets needs to be high, but without creating high shear forces. This usually is accomplished by mechanically inducing collisions between drops or by subjecting the destabilized emulsion to an electrostatic field.