Water injection systems pressure drop

The trace of the sodium flow shows a response peculiar to this system. The sudden flow drop after injection was caused by vaporization of the water which pushed sodium through the flowmeter in the reverse direction to the expansion tank. After this transient, the sodium flow returned to normal, imtil the reaction products reached a vertical leg. The gaseous reaction products then reduced the head on the pump discharge, thereby increasing the flow. The final decrease in flow was probably caused by the reaction products partially plugging the system and thereby increasing the system pressure drop. 

The enhanced recovery of residual oil, which occurs as a consequence of wettability gradients in a reactive alkaline-acidic system, is illustrated in Figure 10. Incremental production in this tertiary flood begins about 0.6 PV after caustic injection and ends after injection of approximately 1.0 PV of caustic. This production is preceded by a pressure peak with a maximum which is two times the steady-state pressure drop of the secondary water-flood. The pressure drop maximum coincides with the concentration minimum of the hydroxyl ion species which elutes at the rear of the tertiary oil bank. 

Venturi scmbbers can be operated at 2.5 kPa (19 mm Hg) to coUect many particles coarser than 1 p.m efficiently. Smaller particles often require a pressure drop of 7.5—10 kPa (56—75 mm Hg). When most of the particulates are smaller than 0.5 p.m and are hydrophobic, venturis have been operated at pressure drops from 25 to 32.5 kPa (187—244 mm Hg). Water injection rate is typicaUy 0.67—1.4 m of Hquid per 1000 m of gas, although rates as high as 2.7 are used. Increasing water rates improves coUection efficiency. Many venturis contain louvers to vary throat cross section and pressure drop with changes in system gas flow. Venturi scmbbers can be made in various shapes with reasonably similar characteristics. Any device that causes contact of Hquid and gas at high velocity and pressure drop across an accelerating orifice wiU act much like a venturi scmbber. A flooded-disk scmbber in which the annular orifice created by the disc is equivalent to a venturi throat has been described (296). An irrigated packed fiber bed with performance similar to a... 

Spray-type collectors In this system water is sprayed or cascaded onto the contaminated air directly or through packed towers, and the fumes or dust are washed away by absorption. These collectors are used extensively on the treatment of fumes of all types and have low pressure drops and hence low power requirements compared to induced spray. A development of this collector is the venturi scrubber, which injects high-pressure water into a venturi through which the fume-laden air is passing. The intimate contact of the two ensures absorption and removal from the air stream. These collectors are used in fume removal and have efficiencies of more than 99 per cent on sub-micron particles. 

Flow assurance engineers for a major energy company (Mehta et al., 2003) indicate that for a two year periods, one of their offshore gas flowlines operated well inside the hydrate formation region. The problem arose from increased water production (to >1000 BPD) over the field life, with limited methanol delivery. Their approach was to inject as much methanol as possible, in the knowledge that they were underinhibiting the system. Due to under-inhibition, there was a gradual increase in the pressure drop (A P) in the line over a period of about 2 weeks, indicating a hydrate build-up on the walls. 

The major process for poly(vinyl chloride) production is the suspension system. Typical reaction temperatures are 50-65 C. As the reaction proceeds, a conversion ( 76%) is reached at which the only monomer left in the system is that absorbed in the polymer particles. This occurs when the monomer concentration is about 30 wt % in the particles. The occurrence of this phenomenon is signaled by a drop in the reactor pressure. Normal pressures in the autoclaves are initially about 150 psig (pounds per square inch, gauge), and it is usual to carry out polymerizations until the pressure drops to about 20-70 psig, depending on the reaction temperature. Water may be injected into the reaction vessel as the polymerization proceeds, to compensate for the volumetric contraction between monomer and polymer. This also helps prevent the reaction mixture from becoming too viscous. As well, the water addition enhances the cooling capacity of the reactor because it increases the heat transfer area on the walls. 

The experimental system is shown schematically in figure 1. Experiments were performed in a straight, smooth-walled acrylic glass pipe 50 mm in diameter. In order to determine the drag reduction from pressure drop measurements the test pipe was provided with 14 pressure taps positioned at I m intervals down the pipe. A sufficient entrance pipe length was provided to ensure fully developed flow at the injection point. The water was pumped from a reservoir tank by a Mohno pump, the speed of which was controlled by a microcomputer to maintain a constant Reynolds (Re) number, during the experiments (between 10 and 10 ). The microcomputer continously measured the temperature of the water with a resistance thermometer and the discharge with a turbine wheel flow meter. 

The main disadvantage of smaller particles is the increased back-pressure during the operation of HPLC systems. The pressure can be calculated according to Darcy s law and is inversely proportional to the square of the particle size. For example, a 33 X 4.5mm column packed with 1.5pm nonporous silica particles needed a pressure of approximately 500 bar (the Umit for most commercial pumps in HPLC units) at a flow rate of 2ml min with acetonitrile and water. A general relation between particle size, pressure drop, plate number, and analysis time is provided in Fig. 7. The assumed specific conditions for viscosity, analyte diffusivity, retention factor, and other parameters are given in the legend. Fast analysis times combined with a limited flow rate also necessitates the need for fast detector systems, small volume detection cells (small volume injection loops, yet, all these challenges have been successfully resolved. 

Note that the comparisons of incremental oil recovery in Examples 5.8 through 5,10 assume that the water and polymer injection rates are constant throughout the flood. Sufficient pressure drop is assumed to exist across the system to maintain the rates at the... 

Example 5,11—Estimation of Pressure Drop During a Continuous Polymer Flood in a Linear Reservoir. Determine the pressure drop for the polymer flood in Example 5.7 when the waterflood front, xpf, is located at a distance of 0.75 from the entrance of the system. Base permeability, the permeability to oil at interstitial water saturation, is 250 md. The ipjection rate is constant at 200 B/D. Recall that the linear segment of the reservoir being simulated is 500 ft wide and 20 ft thick. Injection and production wells are 1,000 ft apart. 

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