SU1666520A1 - Method of crude oil desalting - Google Patents

Abstract

The invention relates to oil refining and oil production, in particular oil desalting. The goal is to improve the degree of desalination. For this, drainage water is preliminarily separated, and then washed with water containing sodium or ammonium nitrates in an intensive dispersion mode in the presence of a demulsifier, followed by settling and separation of released water (it is then better to mix it with oil before preliminary settling in an amount equal to separated drainage water). In this case, the residual water content in the oil is 0.1–0.3 wt.%, Chloride salts 18–48 mg / l versus 0.3% water and 133 mg / l salts in the known case. 1 hp ff, 1 tab.

Description

The invention relates to the oil industry, in particular to the processes of desalting oil in its preparation in the fields.

The purpose of the invention is to increase the degree of desalting of oil.

Examples 1-10. The installation of the preparation of the oil of the Gremikhinsky oil and gas field NGDU Izhevskneft, subjected to steam and thermal effects in the reservoir, comes with the following physical and chemical properties:

Viscosity, mPa.s 180-262

Density, kg / m3 940-960

Water content

wt.% 36-50

The content of chlorides, mg / l 99650-119752

Properties of oil samples after preliminary separation with water separation: Viscosity, mPa-c 141-163 Density, kg / m3 918-920 Water content, wt.% 0.14-2.2

The content of chlorides, mg / l 200-400 Selected samples of the dried oil are treated with aqueous solutions of sodium or ammonium nitrates with intensive movement of a laboratory stirrer for 5 minutes. In addition, 75 g / t deemulsd is metered into oil samples.

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After static settling of the obtained oil emulsions at 55 ° C for 3 hours, the separated water containing nitrates and chlorides is drained.

Example 11-12. The process is carried out as in Examples 1-10, but water containing ammonium nitrate is used for washing. 10

Example 13. The experiment was carried out as in Examples 1-10, but fresh water was used for washing.

Example 14-17. The experiment was carried out as in Examples 1-10, but for washing 15, drainage waters from process equipment, which are solutions of sodium chloride, calcium magnesium, and water are used. In examples 1-17

deep dewatering in a settling tank (OG-200). After dehydration, the nave is sent to the same mixer 4, which serves the ammonium nitrate solution 5, and then to the desalted stage or the dehydrator 6. The ammonium nitrate solution circulates through the cycle: buffer tank 7 - pump 8 - mixer 4 - dehydrator 6 Capacity 7. A part of the drainage of water 2 from the desalting stage, the volume of the drainage water 9 separated from the oil being processed, is directed to the emulsion of the oil in the mixer 1. Drainage 9 from the otostics 3 (OG-200) are directed to the pre-discharge unit (U Ready demineralized and dehydrated

the original oil contains 215 mg / l of oil sent to the fleet.

In tab. 2 shows the results obtained in the processing of oil containing 200-400 mg / l of chlorides and 0 2.2 wt.% Water.

and 1.2% by weight of water.

The results are presented in table. one.

Example 18 The test was carried out as in Example 1, but a portion of the water released during the washing was fed to the mixture with oil before dehydration in an amount equal to the volume of drainage water released during deep dehydration. Before dehydration, the oil contains 20 mg / l of chlorides and 2. 5% by weight of water. After feeding the drainage water for mixing with the emulsion of the drainage water (a solution of nitrates and chlorides), the chloride content after the deep dehydration step is 152 mg / l and water 1.0% by weight against 215 mg / l and 1.2% by weight, respectively without supplying drainage water to the dewatering stage. The content of chlorides at the desalting stage is 25 mg / l (see Table 1).

Example 19. The results of laboratory tests were tested in field conditions at the facility, the technological scheme of which is shown in the drawing.

In a mixer 1 with a movable nozzle, heated nebalsum emulsion is mixed with water 2 released in the desalting stage and fed to

deep dewatering in settler 3 (OG-200). After dehydration, the oil is sent to the same mixer 4, to which ammonium nitrate solution 5 is fed, and then to the desalination stage to the electric dehydrator 6. The ammonium nitrate solution circulates through the cycle: buffer tank 7 - pump 8 - mixer 4 - electric dehydrator 6 - Buffer tank 7. A part of the drainage water 2 from the desalting stage, equal in volume to the drainage water 9 released from the oil being treated, is sent for mixing into the mixer 1 with the oil emulsion. Drainage 9 from the settling tanks 3 (OG-200) are sent to the installation of preliminary discharge (UPS) Ready desalted and dehydrated

Oil is shipped to the fleet.

In tab. 2 shows the results obtained in the processing of oil containing 200-400 mg / l of chlorides and 0.14-2.2 wt.% Water.

There, for comparison, the results obtained when treating the same oil in a similar way, but using fresh water for washing, are given.

Claims (2)

1. A method for desalting oil by pre-separating drainage water, followed by flushing the dried oil with water in an intensive dispersion mode in the presence of a demulsifier, followed by sludge and separating the separated water, in order to increase the degree of desalting, water is used for flushing sodium nitrate or ammonium. 2. The method according to claim 1, wherein the water released during the sludge, after washing, is fed to the mixture with oil before the preliminary sludge in an amount equal to the volume of the separated drainage water. Table 1 Ammonium nitrate solution  2 g / l auth. St. № 1170767 Data on the steps of deep dehydration Table 2 Wash liquid Residual content in oil 1005 1.5 98 0.3 120-150. 32-42 0.2-0.45 0.2-0.41