RU2458726C2 - Method and device for oil dehydration - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to oil processing and may be used for oil dehydration in oil production and petrochemical industries. Proposed method comprises subjecting oil to shock waves originating at high-voltage pulse discharged in water contained in tight cylindrical membrane radiator separated from processed oil-water emulsion and provided with electrodes arranged on its sidewalls. Note here that oil is fed via branch pipe into process tank for it to be separated after processing by hydraulic waves into gas, oil and water to be discharged via appropriate branch pipes.

EFFECT: higher efficiency.

2 cl, 1 dwg

Description

The invention relates to processes for the preparation of oil and can be used for dehydration of oil in the oil and refining industries.

The primary preparation of oil in the oil fields, as is known, is carried out by thermochemical dehydration at elevated temperatures and / or pressures in the presence of a demulsifier. The corresponding plants have significant drawbacks - a large volume of settling equipment, the need for high temperatures and a significant consumption of demulsifier, as well as a relatively long settling time.

Known methods for the destruction of stable oil-water emulsions, based on the creation of areas of micro-fractures in oil in a highly developed turbulent flow with preheating and the addition of surfactants (RF patent 2045982, CL B01D 17/00, B01D 19/00, 1995), under the influence ultrasonic waves (RF patent 2339679 CL. C10G 33/00, from 2008), in an electric field (RF patent 2183132, CL B01D 17/04, from 2002). These and other known methods, representing a combined effect on a water-oil emulsion of several factors, make them technologically complex and require significant energy costs.

The closest in technical essence and the achieved result is a method of separation of oil emulsion under the action of high-voltage electric pulse discharges, causing a shock wave, a sharp increase in pressure and temperature of the medium to be separated (AS No. 1526737, IPC ⁴ B01D 17/06, publ. 07.12 .89 g.). The disadvantage of this method is the need to select the optimal discharge mode (voltage amplitude and distance between the electrodes) not only for oils of various fields, but also in the process of processing the emulsion due to the continuous change in the conductivity of the medium. Deviation from the optimal discharge conditions can cause coking of oil, or the reverse process - emulsion.

Another disadvantage is that the electrodes are in an aggressive environment, causing electrochemical corrosion and pollution, which leads to wear of the electrodes and disruption of the operating mode of the installation. In addition, the direct passage of a spark discharge through oil is undesirable from the point of view of safety in connection with the possibility of explosion of a vapor-gas mixture formed during an electric spark discharge.

The task of the invention is to remedy these shortcomings of the closest analogue and create a reliable, stable method for processing oil emulsions.

The problem is solved in that the high-voltage pulse discharge is not created directly in the treated medium, but in an additional container with water impermeable to the oil-water emulsion, the side walls of which are an elastic membrane. At the same time, hydraulic shocks through the membrane are transferred to the medium to be treated, leading to the destruction of the oil emulsion. Unlike the closest method, the presence of a membrane leads to a more uniform distribution of electro-hydraulic shock power in the working volume, thereby providing a soft and stable mode of destruction of emulsions in almost the entire working volume and eliminating the irreversible coking process. Another distinguishing feature is the discharge is not in the oil-water emulsion, but in the water, which extends the life of the electrodes, and also creates a safe working environment for personnel. In addition, the presence of two working areas provides a more effective demulsification of oil.

The method is as follows (Fig. 1). The oil emulsion is fed into the tank 1 through the inlet pipe 2 with a valve, after which the emulsion enters the first working zone of the tank - zone A, where it is subjected to a hydro-pulse treatment. The source of hydraulic pulses is a sealed membrane emitter 3 located in zone A of a cylindrical shape (made, for example, of polymer elastic materials or thin metal foil), filled with water, with electrodes 4 and 5 placed inside and fixed with dielectric rods 6 and 7 passing through end dielectric plugs 8 and 9 into the cylindrical emitter. The height of the emitter is equal to half the height of zone A, and it is placed in the lower part of the tank to prevent re-emulsification of oil when exposed to water hammer.

From the current pulse generator 10, through the insulators 11 and 12, electrical energy is supplied to the electrodes 4 and 5, between which a short-pulse electric discharge occurs in water (voltage amplitude up to 8 kV, duration about 10 μs). An electrohydraulic shock arising after the discharge through the membrane case 13 of the emitter 3 is transferred to the volume of the treated oil-water emulsion of zone A. The pipe 14 serves to withdraw the vapor-gas mixture resulting from pulsed discharges, and at the same time to replenish the emitter with water.

The cylindrical membrane emitter 3 is located at the same distance from the walls of the tank 1 and the transverse partition 15 made of an elastic material (for example, metal foil). This elastic partition, open to the liquid being processed from above and below, receiving impulses of water hammer from the emitter 3, allows for an even deeper demulsification in the second working zone - zone B.

In the process of processing the oil-gas mixture received in zone A, the process of separation of the flow into gas, oil and water begins. Gas, standing out, occupies the upper part of the tank 1; released water occupies the lower part of the tank and moves freely under the transverse partition 15 to the water outlet pipe 16.

The oil separated from the water flows over the partition 15 into zone B and then collects in zone C, from where it is pumped out through pipeline 17.

Zone B is separated from zone C by a partition 18, the upper level of which is below the screen. Above the inlet of the nozzle 16 for pumping water, there is a horizontal visor 19, which prevents the emulsion from entering the pipeline due to funnel formation.

The separation of gas from oil and water occurs in the entire space of the tank 1, and its removal is carried out through the pipeline 20 under the operating pressure of the apparatus.

A method of oil dehydration, including the effect of an electric discharge, characterized in that the dehydration is carried out in two working zones, while in the first working zone, the main oil dehydration is carried out by water hammer, carried out by electric discharge, which is carried out in a sealed cylindrical membrane emitter located in the lower half of the tank the first working area and at an equidistant distance between its side walls, the end and the transverse elastic partition separating the first working ONU from the second, and the second working area is made further dewatering of oil due to exposure to the transverse elastic septum receiving residual electric discharge pulse emitter membrane.

A device for oil dehydration, consisting of a container with electrodes placed in it, characterized in that the container is divided into zones and dehydration is carried out in two working zones separated by a transverse elastic partition receiving a residual electric discharge pulse, and the electrodes are placed in a sealed cylindrical membrane emitter located in the lower half of the capacity of the first working area and at an equidistant distance between its side walls, the end and the transverse elastic partition.

Thus, the two-stage processing of the oil-water emulsion, in which in the first working zone (zone A) its main separation is carried out into oil and water, and in the second working zone (zone B) is additional in soft mode, provides a more effective demulsification, and the discharge in water - stability, durability, reliability and safety of the installation.

Claims (2)

1. The method of oil dehydration, including the effect of an electric discharge, characterized in that the dehydration is carried out in two working areas, while in the first working area, the main dehydration of oil occurs by water hammer, carried out by electric discharge, which is carried out in a sealed cylindrical membrane emitter located in the lower half of the capacity of the first working area and at an equidistant distance between its side walls, the end and the transverse elastic partition separating the first working from the second zone, and in the second working area is made further dewatering of oil due to exposure to the transverse elastic septum receiving residual electric discharge pulse emitter membrane. 2. A device for oil dehydration, consisting of a container with electrodes placed in it, characterized in that the container is divided into zones, and dehydration is carried out in two working areas, separated by a transverse elastic partition receiving the residual impulse of electric discharge, and the electrodes are placed in a sealed cylindrical a membrane emitter located in the lower half of the capacity of the first working area and at an equidistant distance between its side walls, the end and the transverse elastic partition.

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