RU2632017C2 - Oil dehydration and demineralisation device - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device contains a remote oil mixer (3) with fresh flushing water and a water chamber (2) for oil flushing and a settling chamber (11) located in a common body (1) separated by transverse partition (10). The settling chamber is an electric precipitation chamber. The device can further comprise a pre-dewatering chamber. A gas separation chamber can be additionally installed on the body of the pre-dewatering chamber. There are one or more injector mixers placed vertically or under inclination in the water flushing chamber and provided with nozzles (4) and coaxial mixing nipples (5) in the lower part.

EFFECT: increased efficiency of oil dehydration and demineralisation by increasing time for mixing oil with water at high water-oil ratio.

7 cl, 5 dwg

Description

The invention relates to equipment for the preparation of oil and can be used in the oil and oil refining industries, in particular for dehydration and desalting of oil.

The processes of dehydration and desalting of oil are based on the destruction of the emulsion, its demulsification. In this case, when desalting, the emulsion is subjected to an artificial emulsion of oil with wash water, specially supplied to wash the oil from the salts remaining in it. To destroy the emulsion in the processes of dehydration and desalting of oil, gravitational sludge is used, which is combined with various measures of action on the emulsion - heating, the addition of demulsifiers, mixing and electric processing.

Closest to the claimed apparatus is an installation for dehydration and desalination of oil, including a remote mixer of oil with fresh washing water, a chamber for water washing of oil with a system for introducing a mixture of oil with fresh water, a settling chamber, the water washing chamber and the settling chamber separated by a partition [RF Patent No. 2302281].

A disadvantage of the known installation is the low efficiency of the oil desalination process, since the interaction of oil with fresh washing water in the mixer occurs at a water / oil ratio determined by the material balance, i.e. in the range of 0.03-0.07.

The objective of the invention is to significantly increase the efficiency of the process of desalination of oil.

The technical result achieved by using the invention is to increase the efficiency of the process of dehydration and desalination of oil by increasing the mixing time of oil with water at a high ratio of water / oil (above 1.0), i.e. with an increase in the interfacial surface during mass transfer.

The specified technical result is achieved by the fact that in the apparatus for dehydration and desalination of oil, including a remote oil mixer with fresh washing water and placed in a common housing, separated by a transverse partition, a chamber for water washing of oil and a settling chamber, one or several injection mixers with nozzles located in the lower part and mixing nozzles coaxial to them.

The specified technical result is also achieved by the fact that as a settling chamber, an electrodeposition chamber is used.

The specified technical result is also achieved by the fact that the apparatus further comprises a preliminary dewatering chamber.

An additional gas separation chamber may be additionally installed on the body of the pre-dewatering chamber.

The invention is illustrated in FIG. 1-5.

In FIG. 1 schematically shows an apparatus for dehydration and desalination of oil, where: 1 - the apparatus body, 2 - a chamber for water washing of oil, 3 - node for introducing a mixture of oil with fresh washing water, 4 - a nozzle, 5 - a mixing pipe, 6 - oil distribution system, 7 - a collection of separated water, 8 - a demineralized oil collection system, 9 - a demineralized oil outlet fitting, 10 - a partition, 11 - a settling chamber, 12 - a level gauge, 13 - an oil collection system, 14 - a riser.

In FIG. 2 schematically shows an apparatus for dehydrating and desalting oil, similar to the apparatus in FIG. 1, in which, as a settling chamber 11, an electrodeposition chamber with an electrode system 15, a high voltage power supply 16 and a high voltage cable 17 is used.

In FIG. 3-5 shows various embodiments of the proposed apparatus for dehydration and desalination of oil, designed to process raw materials of different compositions.

The apparatus for dehydration and desalting of oil (Fig. 1) contains a horizontal cylindrical body 1, a chamber for water washing of oil 2, a unit for introducing a mixture of oil with fresh washing water 3 with a nozzle 4 in the lower part and a mixing pipe 5 coaxial to it, an oil distribution system 6, a collection of separated water 7, a demineralized oil collection system 8 with a demineralized oil outlet fitting 9.

The unit for introducing the oil mixture with the washing water 3 is located in the water oil washing chamber 2, separated by a fresh transverse partition 10 from the settling chamber 11, which is equipped with a level gauge 12. In the upper part of the water oil washing chamber 2 there is an oil collection system 13 connected by a riser 14 to the system 6 distribution of oil settling chamber 11.

In FIG. 3 shows an apparatus for dewatering and desalting oil with a high inlet water cut, which comprises water oil flushing chambers 2 and electrodeposition 11 identical to those shown in FIG. 2. However, this apparatus, designed for dehydration and desalting of oil with a high input water cut, is also equipped with a preliminary dehydration chamber 18, which contains an inlet feed distributor 19 with a collector 20, a dehydrated oil collection system 21, a riser 22 for dehydrated oil output, and a collection system produced water 23 with an outlet fitting 24. The assembly 3 for introducing fresh washing water into the dehydrated oil and introducing their mixture through the nozzle 4 into the water washing chamber 2 is identical to that shown in FIG. 1. The camera 18 is equipped with a level gauge 25.

In FIG. 4 shows a variant of the apparatus for desalting and dehydration of gas-saturated oil. By analogy with the embodiment of the device shown in FIG. 3, the apparatus contains pre-dewatering chambers 18, water washing 2 and electrodeposition 11. Since free gas must be removed from gas-saturated oil for effective dehydration and desalination processes, a gas separation chamber 26 is additionally installed on the body of the pre-dewatering chamber 18. A gas separation chamber 26 is inserted into its bottom 27. a raw material distributor 19 connected to a collector 20 of the dehydration chamber 18. In the upper part of the chamber 18, a dehydrated oil collection system 21 is mounted, the riser 22 is dehydrated oil produced water collection system 23 to fitting 24. The outcoupling unit input oil mixed with fresh washing water 3 in oil and dehydrated input mixtures thereof in an aqueous washing chamber 2 identical to that shown in FIG. 1-3. The chamber 18 is equipped with a level gauge 25. The gas separation cap 26 is equipped with an inlet fitting 28, a lower bottom 27 into which the raw material distributor 19 is welded, a nozzle for gas outlet 29 and a fitting for level control 30. A second gas separation cap 31 is installed on the water washing chamber 10.

In FIG. 5 shows a variant of the apparatus for dehydration and desalination of oil, designed to prepare heavy emulsions that are difficult to separate by gravity sludge. The apparatus comprises water washing chambers 2 and electrodeposition 11 identical to those shown in FIG. 2. However, to ensure deep oil dehydration in the first stage of this embodiment of the apparatus, the preliminary dewatering chamber 18 is equipped with an electrode system 33, a high-voltage power supply 34 and a high-voltage input 35 and contains an input raw material distributor with a fitting 32 connected to the collector 20, as well as a dehydrated collection system 21 oil with riser outlet for dehydrated oil 22. The node for introducing fresh washing water 3 into dehydrated oil and introducing their mixture into the water washing chamber 2 through nozzle 4 and pipe 5 is identical to the display nnomu FIG. 1. The camera 18 is equipped with a level gauge 25.

The proposed apparatus (Fig. 1) works as follows.

Oil mixed with fresh water through the input unit 3 enters the nozzle 4 and, flowing out of it, injects the accumulated water in the lower part of the water washing chamber for oil 2. In the mixing nozzle 5, a highly watered, unstable emulsion is formed, which quickly decomposes into oil and water after leaving the mixing nozzle 5 in the volume of the chamber 2. The aqueous phase of the emulsion goes down and thus repeatedly circulates in the volume of the water washing chamber 2. The water / oil ratio in the mixing pipe 5 is many times higher than at the inlet of the apparatus, which achieves a good washing of oil with water and the transition of salts into the aqueous phase. The water level in the water washing chamber 2 is set by itself depending on the oil flow rate, the dispersed composition of the water, the surface tension, the density and viscosity of the oil and water.

Oil is collected in the upper part of the water oil washing chamber 2 and through the collection system 13 through the riser 14 it enters the oil distribution system 6 of the settling chamber 11. During the lifting of oil from the oil distribution system 6 to the desalted oil collection system 8, water droplets contained therein are deposited way down. Together with water, the salts dissolved in it also leave the oil. As a result, dehydrated and desalted oil enters the collection system 8 of the settling chamber 11, which is removed from the apparatus through the nozzle 9. Water with salts is collected in the lower part of the apparatus. Using the level gauge 12 maintain its level, which provides a sufficient time for settling water from particles of oil products. Excess water is discharged through a reservoir of separated water 7.

In addition to all the nodes of the design and features of the apparatus shown in FIG. 1, the settling chamber of the apparatus shown in FIG. 2, is equipped with an electrode system 15, when passing through which the process of deposition of droplets of water contained in the oil is particularly intense. Here, water droplets merge with each other under the influence of electric forces, and the sedimentation rate of large drops of water is higher than small ones. The efficiency of the apparatus for dehydration and desalination of oil (Fig. 2) containing the electrode system is much higher than the apparatus with a gravitational settling chamber (Fig. 1).

Together with water, the salts dissolved in it also leave the oil. As a result, dehydrated and desalted oil, which is removed from the apparatus through the nozzle 9, enters the collection system of desalted oil 8 of the electroplating chamber 11. Water with salts is collected in the lower part of the apparatus. Using the level gauge 12 maintain its level, which provides a sufficient time for settling water from particles of oil products. Excess water is discharged through a reservoir of separated water 7.

The apparatus (Fig. 3) works as follows.

Crude oil containing highly mineralized produced water is introduced into the input distributor of raw materials 19. Using the collector 20, the oil is evenly distributed over the section of the chamber 18 and, rising in it, is freed from the produced water, which settles down, accumulates there in the form of a continuous aqueous phase, is collected the system for collecting produced water 23 and leaves the apparatus through the fitting 24.

Dehydrated oil always contains residual salts, and in order to reduce their amount, it is discharged through riser 22, mixed with fresh washing water, and through mixing unit 3, nozzle 4 and mixing pipe 5 are introduced into the water washing chamber 2. The washed oil from the upper part of the chamber water washing 2 through the oil collection system 13 and the riser 14 is introduced into the oil distribution system 6 of the precipitation chamber 11, during the passage of oil through which the water and its salts are separated, i.e. desalination of oil. Oil is removed from the apparatus through the nozzle 9, and water from the desalination chamber through the collector of separated water 7.

In the pre-dewatering chamber 18, a constant water level is maintained using a level gauge 25, discharging the settled water through its collection system 23 and fitting 24.

The apparatus shown in FIG. 4, works as follows.

Raw materials consisting of oil, gas and produced water are fed into the apparatus through the nozzle 28 of the gas separation chamber 26, in which the gas discharged through the nozzle 29 is separated from the liquid. The liquid level in the chamber 26 is maintained by a level gauge connected to the chamber 26 through the nozzle 30 The fluid, which is a mixture of oil with produced water, is introduced into the chamber 18 through the distributor 19. Using the collector 20, the oil is evenly distributed over the section of the chamber 18 and, rising in it, is freed from the produced water, which settles down, accumulate camping there in the form of a continuous aqueous phase, it is going to produced water collection system 23 and out of the device via the connection 24.

Dehydrated oil always contains residual salts, and, in order to reduce their amount, it is discharged through riser 22, mixed with fresh washing water, and through mixing unit 3, nozzle 4 and mixing pipe 5 are introduced into water washing chamber 2, from which through gas separation cap 31 remove residual gas. The washed oil from the upper part of the water washing chamber 2 through the oil collection system 13 and the riser 14 is introduced into the oil distribution system 6 of the electrodeposition chamber 11, during the passage of oil through which the water and its salts are separated, i.e. desalination of oil. Desalted oil is removed from the apparatus through the nozzle 9, and water from the electrodeposition chamber 11 through the collector of separated water 7.

The apparatus shown in FIG. 5, works as follows.

Crude oil containing highly mineralized produced water is introduced through the union of the input feed distributor 32 into the reservoir 20. Using this collector, the oil is evenly distributed over the section of the preliminary electro-dewatering chamber 18 and rises in it, passing through the interelectrode space of the electrode system 33. In the electric the emulsion field collapses, water droplets coarsen and settle down, accumulating there in the form of a continuous aqueous phase, which is collected by collector 23 and removed from the apparatus through es fitting 24.

The optimum water level in the dehydration chamber 18 is maintained using a level gauge 25.

Even deeply dehydrated oil in an electric field always contains residual salts, and in order to reduce their amount, oil is removed through riser 22, mixed with fresh washing water and through mixing unit 3, nozzle 4 and mixing pipe 5 are introduced into water washing chamber 2. Next, washed and the oil settled in the chamber 2 through the collection device 13, the riser 14 and the oil distribution system 6 is introduced into the electro-deposition chamber 11, where water with salts dissolved in it is separated from it, as a result of which the oil is desalted. Desalted oil is discharged from the apparatus through collectors 8 and a nozzle 9 connected to them, and water from the electrodeposition chamber 11 is discharged through a collector of separated water 7.

The indicators of the process of dehydration and desalination of oil are largely determined by the organization of the process of mixing oil with water. Maximum efficiency is achieved with a large interface, i.e. when water washing oil with plenty of water. In this case, salts more efficiently pass into the aqueous phase and precipitate together with water. Typically, a mixture of oil and water is produced by dispersing water in an amount of from 2 to 10% in the oil stream by creating a pressure drop either in the water stream or in the oil stream in a mixture with washing water. The possibilities of creating a large interphase surface using known devices are limited both by the possibility of introducing large quantities of fresh water into the oil (with subsequent withdrawal) for economic and environmental reasons, and by the danger of very fine dispersion of fresh water, since then this water will need to be separated from the oil (than the smaller the drops of water, the more difficult it is to remove them).

In the claimed device, a large interfacial surface is created due to the multiple circulation of water in the water oil washing chamber. The water / oil ratio in the mixing nozzle integrated in this chamber can reach 1.5-2. The maximum value of the specific interfacial surface is achieved with a water / oil ratio at the phase inversion point, i.e. transition from inverse emulsion (water in oil) to direct (oil in water). It is precisely under these conditions that the nozzle 4, the mixing nozzle 5, and the entire design of the water washing chamber are calculated.

The described variants of multi-sectional apparatus for dehydration and desalting of oil can increase the efficiency of the process of dehydration and desalination of oil by increasing the time of mixing oil with water at a high ratio of water / oil. This increase in time compared with known analogues is achieved by placing the oil mixer in a separate chamber for water washing of oil, in the lower part of which there is a nozzle for the flow of oil inside the coaxial nozzle of the mixing nozzle.

Claims (7)

1. Apparatus for dehydration and desalting of oil, comprising a remote oil mixer with fresh washing water and placed in a common housing separated by a transverse partition a chamber for water washing of oil and a settling chamber, characterized in that in the chamber of water washing of oil placed one or more injection mixers with placed in the lower part by nozzles and mixing nozzles coaxial to them. 2. The apparatus according to claim 1, characterized in that the injection mixers in the chamber for water washing of oil are placed vertically or obliquely. 3. The apparatus according to claim 1, characterized in that an electro-precipitation chamber is used as a settling chamber. 4. Apparatus for dehydration and desalting of oil, including a remote oil mixer with fresh washing water and placed in a common housing separated by a transverse partition chamber for water washing of oil and settling chamber, characterized in that the apparatus further comprises a chamber for preliminary dehydration, and in the chamber for water washing of oil placed one or more injection mixers with nozzles located in the lower part and mixing nozzles coaxial to them. 5. The apparatus according to claim 4, characterized in that the injection mixers in the chamber for water washing of oil are placed vertically or obliquely. 6. The apparatus according to claim 4, characterized in that an additional gas separation chamber is additionally installed on the body of the preliminary dewatering chamber. 7. The apparatus according to claim 4, characterized in that an additional gas separation chamber is additionally installed on the casing of the oil water washing chamber.

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