SU1007695A1 - Oil desalination and dehydration method - Google Patents

Abstract

METHOD OF DECOMPOSITION AND REALIZATION OF OIL, including gas separation, preliminary and final sedimentation, elimination of oil-water emulsion with demulsifier and drainage water released during the final sedimentation process, characterized in that, in order to get the clear water, the material is spent in the final sedimentation process, by means of a transparent silicon and a transparent tooth that is spent in the process of final sedimentation, in order to get a clear tooth, the material is spent by the end of the process of final sedimentation, in order to get a clear tooth, the material will be spent by the end of the process, finally, will be spent by means of a clean water, and will be covered with a transparent tooth that will be spent by the end of the process by means of a final wash, by means of a transparent silicon and white water that is extracted by means of a clean water, by means of a transparent water, and by means of a transparent wax that will be spent by the end of the process; wherein the total water content of the emulsion is at least 40 vol. / o and before preliminary settling, the mixture of degassed emulsion and drainage water is transported through the pipeline in a turbulent mode for 1.5–20 min. 9 1sl

Description

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The invention relates to the oil and petrochemical industry, in particular to the processes of dehydration and desalting of oil.

There is a known method for the dehydration and desalting of oil, including degassing, heating, and treating it with demulsifying agent 1.

The disadvantage of this method is that the water separating from the oil during the dewatering and desalting process contains a large amount of oil and mechanical impurities, which therefore requires cleaning on bulky and expensive structures (oil traps, sedimentation ponds, filters, etc.) .

The closest to the proposed technical essence is a method of oil dehydration and desalting, including gas separation, preliminary and final sedimentation, treatment of a water-oil emulsion with a demulsifier and drainage water released during the final sedimentation process 2.

A significant disadvantage of the method is that the introduction of drainage water into a stream of aerated oil, careful movement and degassing is accompanied by intensive crushing of oil particles in water, and therefore the water discharged from the separators contains a large amount of contaminants (up to 30,000 mg / l of oil and 350 mg / l suspended solids) and requires cleaning.

The purpose of the invention is to obtain pure water in the process of dehydration and desalting of oil.

The goal is achieved by the fact that in the method of dehydration and desalting of oil, including gas separation, preliminary and final sedimentation, treatment of a water-oil emulsion with a demulsifier and drainage water released during the final sedimentation, the drainage water is fed into the degassed emulsion in which the total content water in the emulsion will be at least 40 vol. % and before preliminary settling the mixture of degassed emulsion and drainage water is transported through the pipeline in the turbulent mode for 1.5-20 minutes.

At the same time, the packing of water droplets is close to Dense or extremely possible, which ensures that the droplets of the water being purified are in firm contact with the formation drops. The latter perform the role of a mobile coalescing medium that absorbs the contents of the droplets of water being purified. The contaminants (particles and oil) are transferred mainly to the oil phase at the moment of rupture of the oil films separating the droplets.

As microscopic surveys have shown, the drops of the produced water themselves practically do not contain contaminants and do not need to be cleaned.

In this case, the degassed water-to-oil emulsion acts as a contact mass that absorbs hydrophobic impurities contained in water.

The method is carried out as follows.

The water cut in the raw material pipeline is determined, through which it is transported to a thermochemical dewatering and desalting plant (TCU). The water to be purified, which is separated at this installation, is introduced into the pipeline of a degenerated water and oil emulsion at a distance that allows the mixture to be transported to the preliminary oil dewatering tank for 1.5-5 20 minutes.

The total amount of water in the emulsion should be more than 40%. From the pre-dewatering tank, an emulsion containing 10-12% of water is sent to the installation for its preparation, and purified water from its lower part is sent to a buffer tank, from which it is then pumped into the reservoir flooding system.

The test showed that the lowest oil content of other impurities in the waste water when it was cleaned using the proposed methods is achieved at ratios

rueQ is the total consumption of water contained in the emulsion after adding additional water to it; QH-oil consumption.

With a lower content of the total amount of water in the emulsion, it is converted into finely dispersed with mixing and its separation process is very complicated.

Wastewater treatment using the proposed technology can be carried out at any initial water content in oil below the optimum. It is important that 1.5–20 minutes before entering the pre-dewatering tank in the emulsion there is more than 40% water. This can be achieved, for example, by accumulating waste water and periodically diluting it with an emulsion of oil coming from wells.

It is impractical to establish the upper limit of the initial water content in oil, since with high water content, up to 99%, the cleaning process will be even more efficient, since there will already be, basically, pure water. The time of transportation of the emulsion on the sludge in the turbulent mode after the introduction of wastewater into it is established

5 experimentally and depends on the total amount of water in the emulsion. In this case, a lower limit (1.5 minutes) is sufficient with the highest possible water content in the emulsion, and a higher limit (20 minutes) is necessary with a minimum content. Example 1. The watered paraffinic oil produced from the Devonian formations is density. 9,667 g / cm in the amount of 9000 were degassed in separators with an absolute pressure of 1.1 kgf / cm and 12 ° C. Refined oil contained 20 vol. % of calcium chloride type formation water with a salinity of 150 g / l. Hazardous wastewater containing 2620 mg / l of oil and 153 mg / l of suspended solids, separated into TCA, was calculated in the oil at a rate of 3000. The temperature of the injected water was 42 ° C. The mixture at 27 ° C, consisting of oil and 40% water, was transported through a pipeline with a diameter of 300 mm and a length of 2.16 km for 20 minutes under a turbulent regime characterized by a Reynolds number of about 7950. The water-oil mixture thus processed was injected 5,000 m of oil was taken from the upper part of the tank with 10–12% water content and sent to the TCA for final dehydration and desalting, and a purified wastewater was taken from the bottom of the tank through the hydraulic lock to the buffer tank. th water containing 30-45 mg / l of oil and 35- 50 dr / l suspended solids. Water of this quality was pumped from the buffer tank into Devonian oil deposits to maintain reservoir pressure. Example 2. Extracted from carbonate reservoirs sulfur oil with a density of 0.9000 g / cm in the amount of 660, was degassed in separators at an absolute pressure of 1.2 kgf / cm. The water content of the distilled sour crude was 55%, the temperature was 9 ° C. Then, 3860 water discharged from the emulsion plants with a temperature of 38 ° C, hydrogen sulfide containing 120 mg / l, 1840 mg / l oil and was added to this oil. 115 mg / l suspended solids. The mixture at 35 ° С, consisting of 86% water and 14% oil, was transported by pipeline with a diameter of 200 mm and a length of 150 m for 1.5 minutes in a turbulent regime characterized by a Reynolds number of 23,000. The water-oil mixture thus treated was injected in four horizontal sedimentation tanks of 200 m each. Oil with a water cut of 10–13% was removed from the upper part of the settling tanks, and purified water with a content of 28–37 mg / l of oil and 44–60 mg / l of suspended solids was removed from its lower part. Purified water was collected in a closed container with a volume of 100 m and pumped out of it into the carbonate reservoir flooding system. The application of the proposed method allows the process of dewatering and desalting of oil to simultaneously purify the separated water at the lowest cost and to use it in reservoir flooding systems. So, if, with the well-known technology of oil treatment, the waste water containing 160–1543 mg / l of emulsified oil and 47–102 mg / l of suspended solids on TCA, then using the proposed method, the water after leaving this installation contains only 24 - 58 mg / l of emulsified oil and 38- 52 mg / l of suspended particles, i.e., it is already suitable for use in a water-flooding system without further purification. In this case, there is no need for the construction of expensive and bulky structures, such as oil traps, ponds, filters, etc., which require their qualified service.

Claims (1)

METHOD FOR DEWATING AND SALTINING OIL, including gas separation, preliminary and final sedimentation, treatment of the oil-water emulsion with a demulsifier and drainage water released during the final sedimentation process, characterized in that, in order to obtain clean water, drainage water is supplied to the degassed emulsion in an amount at which the total water content in the emulsion is at least 40 vol. % and before preliminary sedimentation, the mixture of degassed emulsion and drainage water is transported through the pipeline in a turbulent mode for 1.5-20 minutes. Joint venture