SU1502050A1 - Method of purifying oil-production waste water - Google Patents

Abstract

The invention relates to the treatment of oily wastewater and can be used in the preparation of oilfield wastewater for injection into productive formations. The goal is to increase the filtration rate by reducing the coalescence time of water droplets at the oil-water interface. At the oil – water phase interface, an electric field is applied with power lines perpendicular to the interface. The grid electrodes are placed over the entire cross-sectional area above and below the interface. The strength of the electric field is maintained in the range of 400 ... 800 V / m. At the same time, the filtration rate can reach 12 m / h. 1 hp ff, 2 ill., 2 tab.

Description

The invention relates to the treatment of oilfield wastewater and can be used in the preparation of oilfield wastewater;; | pumping into productive la1. you.

The aim of the invention is to increase with ke / growth and filtration.

Purification of oily wastewater is dried by filtering through a layer of oil with an entire area of 11 which is placed in it (1 is a cross-section of a mesh electrode. M of a second screen) 1Y e.protrode is stirred up along the entire surface of the cross section and c. water Thus, with respect to the oil-water phase interface, an electric field is created (a primary field with power., Perpendicular to the interface. In the absence of a water droplet at the C interface) and the oil-water lines, the power lines are parallel to each other without distorting , forming at the phase boundary electric charges, opposite in sign. Drying of lines of force on the floor; electric floor in

water droplet leads to its stretching. The gravitational force of the body acting on the water droplet deforms it. The various actions of these factors lead to a rapid disruption of the oil film, which prevents the drop of water from c and water.

FIG. Figure 1 shows a device for determining the dependence of the coalescence time on the criminality of the electric ion; in fig. 2 installation, in Koropoii, the proposed method is implemented.

(In order to detect the dependence of the coalescence of water droplets or the electric field strength, we conducted studies using a laboratory) setup (Fig. 1). The installation includes a flat glass container 1. in which e., Electrodes 2 and 3 are fixed along the entire surface of the cross section above and below the 4 phase interface of mas. S 5 - water 6. For giving out; seams over the surface of the oil cap. O) vid s.pzhit kaшsl r stalagmomegra 7. In a glass nali.i 0.1 n, solution of chlorine sodium.

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above - layers of vaseline oil with a thickness of 20 mm. Graphite grids with a cell size of 5x5 mm were used as electrodes. One electrode was located above the interface of the oil-water phase at a distance of 10 mm from it, and the second - below the interface also at a distance of 10 mm. Using a stalagmometer with a glass capillary 0.5 mm in diameter, a drop of water was squeezed out above the oil layer. A voltage in the range of 0 ... 25 V was applied to the electrodes. The time of coalescence of a drop of water at the interface of the oil-water interface was measured with a stopwatch.

The data presented in Table. one.

As the results of the research showed, the shortest coalescence time was observed in the range of electric field strengths 400 ... 800 V / m.

In order to determine the maximum possible filtration rate at which the quality of cleaning was no worse than in the prototype, studies were carried out using the setup shown in FIG. 2. The installation includes a glass cylinder (cup) 1 with a diameter of 200 mm and a length of 1000 mm, in which mesh graphite electrodes with a cell size of 5x5 mm are attached over the entire cross-sectional area. One electrode 2 is located at a distance of 10 mm from the border of 4 sections of oil (oil) 5 - water 6 in the oil layer, the second electrode 3 is also in the water layer at a distance of 10 mm from the interface. The source water is fed through a hopper distributor 8. The purified water is taken to the vessel 9.

Pure water was poured into the installation with a layer thickness of 800 mm, on top - a layer of oil 200 mm thick. The original oil-containing water was fed through a perforated distribution; 1 thread with a hole diameter of 1 mm. The oil content in the source water is 650 mg / l.

The research results are presented in Table. 2

The highest filtration rate (12.2 m / h) is achieved with an electric field strength of 600 V / m.

Example. Oil-containing water with an oil content of 1000 mg / l was purified. Electric field intensity 600 V / m filtration speed 12 m / h. The oil content in the purified water is 25 ... 27 mg / l.

Claims (2)

1. A method for treating oilfield wastewater by filtering through a layer of oil, characterized in that, in order to increase the rate of filtration, at the oil-water interface create an electric field with power lines perpendicular to the separation section as well. 2. A method according to claim 1, characterized in that the strength of the electric field is 400.800 V / m. Table 1 table 2