Brine channels

Brine channels — Small passages in the lower surface of first-year sea ice that are formed by the exclusion of saline water or salts during rapid freezing. Researchers have found that oil under first-year ice will migrate through the brine channels when the ice begins to melt in the spring. (See also First-Year Ice.)... 

First-year ice — Ice formed during the winter of a given year in the Arctic regions that does not contain residual or polar pack ice from previous years. First-year ice is characterized by the presence of brine channels and is relatively porous compared to pack ice. (See also Brine channels.)... 

During the 60-s pre-service flush cycle, the RO high-pressure pump is off while the RO membrane brine channels are flushed with water at line pressure (<2 bar g). The pre-service flush cycle is followed by a 5-min quality rinse cycle when the RO permeate is diverted to the water reuse tank, T-200, via the divert valve, MV-161-4. 

The flow conditions in the thin feed brine channel with feed brine spacers in between is complex (see Schwinge et al. (2002, 2003) for the unsteady flow, vortex shedding and mass-transfer enhancement in spacer-filled channels). The complexity is captured by using an empirically... 

An additional feature of a spiral-wound module is of interest i.e. the number of feed brine channels in a module. There can be as many as four feed brine channels around one central collection tube two membrane packets next to each other and separated by a feed side spacer create one membrane channel. The membrane surface area per unit device... 

The total molar solute permeation rate through the two membranes lining one feed brine channel may now be employed to determine Cip, the average concentration of solute i in the permeate whose volumetric production rate through the two membranes is Qpermeate ... 

The effect of lower oil saturation and location of injection wells can be demonstrated by the next example of some wells in Oerrel (Figs. 11 and 14). In this unit, polymer injection started down-dip at the oil water contact. The injected solution was partly lost in the aquifer. The distance to up-dip wells was too large. It is assumed that the polymer bank was also diluted by high-salinity reservoir brine channeling through permeable zones in the middle part of the reservoir. Oil banking could only be achieved by additional injection in Well O.S. 57. The small oil banks correspond to the low oil saturation in this region. 

Fig. 25. OxyTech MGC electroly2er a, membrane b, anode assembly c, manifold spacer d, anolyte outlet e, catholyte outlet f, bulkhead g, brine inlet h, NaOH inlet i, insulating channel j, bulkhead insulator k, interface material 1, cathode assembly m, interceU bus n, tie rod o, current distributor p,...

The core - flood apparatus is illustrated in Figure 1. The system consists of two positive displacement pumps with their respective metering controls which are connected through 1/8 inch stainless steel tubing to a cross joint and subsequently to the inlet end of a coreholder 35 cm. long and 4 cm. in diameter. Online filters of 7 im size were used to filter the polymer and brine solutions. A bypass line was used to inject a slug of surfactant solution. Two Validyne pressure transducers with appropriate capacity diaphragms are connected to the system. One of these measured differential pressure between the two pressure taps located about one centimeter from either end of the coreholder, and the other recorded the total pressure drop across the core and was directly connected to the inlet line. A two - channel linear strip chart recorder provided a continuous trace of the pressures. An automatic fraction collector was used to collect the effluent fluids. 

When comparing the gas-drive processes GDS and GDW the presence of surfactant in the displaced liquid has a great effect on the displacement mechanisms and flow patterns. Figure 9 shows schematically the final extent of sweep for gas-drive of brine without surfactant (Frame a) and with surfactant (Frame b). In each case the gas appears to have preferentially flowed through a few large channels that zig-zag across the raicromodel however, in... 

The primary reaction of alkali with reservoir water is to reduce the activity of multivalent cations such as calcium and magnesium in oilfield brines. Upon contact of the alkali with these ions, precipitates of calcium and magnesium hydroxide, carbonate, or silicate may form, depending on pH, ion concentrations, temperature, and so on. If properly located, these precipitates can cause diversion of flow within the reservoir, leading to better contact of the injected fluid with the less-permeable and/or less-flooded flow channels. This then may contribute to improved recovery. Also, this reduction of reservoir brine cation activity will lead to more surfactant activity, resulting in lower IFT values (Mayer et al., 1983). 

Figures 4.3(a) and (b) are sections in the zx-plane showing the distribution of potential (( )) in the solution as cross sections of imaginary surfaces in the solution of equal potential (isopotentials) and the distribution of current as current channels with cross sections defined by traces of the surfaces. ..(n - l),n, (n + 1)... perpendicular to the isopotentials. These traces are located such that each current channel carries the same total current. Figure 4.3(a) applies to an environment of higher resistivity (e.g., water with specific resistivity of 1000 ohm-cm) and Fig. 4.3(b) to an environment of lower resistivity (e.g., salt brine, 50ohm-cm). The figures are representative of anodic and cathodic reactions, which, if uncoupled, would have equilibrium half-cell potentials of E M = -1000 mV and E x = 0 mV and would, therefore, produce a thermodynamic driving force of Ecell = E x - E M = +1000 mV. This positive Ecell indicates that corrosion will occur when the reactions are coupled. For the example of Fig. 4.3(a), the high solution resistivity allows the potential E"m at the anode to approach its equilibrium value (E M = -1000 mV) and, therefore, allows the potential in the solution at the anode interface, < )s a, to approach +1000 mV (recall that (j)s = -E"M). The first isopotential above the anode, 900 mV, approaches this value. The solution isopotentials are observed to decrease progressively and approach 0 mV at the cathode reaction site.

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