HARMFUL EFFECTS OF OILY SALTS AND MEASURES TO COMBAT THEM

ABSTRACT

In this article, the negative effect of mineral salts in formation waters, which are produced together with oil, on oil preparation and processing equipment is studied. The use of demulsifier-surfactants has been recommended as a measure to combat negative effects by reducing the mass of chlorine salts in oil. With this, it will be possible to extend the service life of the equipment, prevent the decrease in the quality of the manufactured products, and improve the economic indicators.

АННОТАЦИЯ

В данной статье изучается негативное влияние минеральных солей в пластовых водах, которые добываются вместе с нефтью, на оборудование для подготовки и переработки нефти. Использование деэмульгаторов-поверхностно-активных веществ было рекомендовано в качестве меры по борьбе с негативными эффектами за счет снижения массы солей хлора в масле. Благодаря этому можно будет продлить срок службы оборудования, предотвратить снижение качества выпускаемой продукции и улучшить экономические показатели.

Keywords: oil emulsion, formation water, surfactant, chlorine salts, alkaline salts, demulsification, equipment, corrosion, oil product.

Ключевые слова: нефтяная эмульсия, пластовая вода, поверхностно-активное вещество, соли хлора, щелочные соли, эмульгирование, оборудование, коррозия, нефтепродукты.

Introduction. Formation waters, which are mined together with oil and form a dispersed system with it, contain a significant amount of dissolved mineral salts. According to the chemical composition, the formation waters are mainly chlorcalcic and alkaline, consisting of a mixture of sodium, magnesium and calcium chlorides.

Methods. The results of a large number of studies on the mineral composition of aquifers show that the main part of dissolved substances is sodium, magnesium and calcium chlorides, iodine and bromine salts of alkaline and alkaline earth metals, sodium, iron, calcium sulfides, lead can also be vanadium, germanium salts, etc.

The oil itself does not contain chlorine salts. Salts fall into it together with emulsified waters. The amount of crystalline salts in oil is in the range of 10-15 mg/m³. Some of the crystallized salts sink and form a solid crust. Sometimes these salt crusts break off, move with the oil flow, and settle into the equipment. Therefore, the problem of the formation of chloride salts in oil, their negative effects in oil processing, and the method of controlling the mass fraction of chlorine salts in oil in laboratory conditions are very relevant [1,2]. The amount of salt in the oil causes heavy and various difficulties in its processing. The amount of salt in oil is 2000-3000 mg/l , in some cases it reaches 0.4-0.3%. Such oils cannot be processed under normal conditions.

Contamination of structures (I) . Salts are released the most in hot installations. Salts dissolved in water are also released when the water evaporates. It is known that the temperature of devices in the industry is high, and they are cooled from the outside through the cooling system . However, at the limits of heat exchange of structures and near it, the process of accumulation of salts on the surface takes place, and as a result, salt crystals gather in the form of crystals and form a hard and durable crust. Sometimes these salt crusts are fractured and transported along the oil flow to subsequent units, thereby forming deposits in the subsequent units.

Corrosion of devices (II) . In the process of oil production, the accumulation of solid inorganic substances is observed in the well wall and riser pipes, pumping equipment and surface facilities of the oil collection and preparation system. Accumulation of salts complicates oil production, leads to the failure of expensive equipment, large-scale maintenance work, resulting in incomplete production and loss of oil. Corrosion of metal under the influence of liquids occurs somewhat differently. The compound formed as a result of corrosion can re-melt and promote further corrosion. In addition, water and solutions with substances dissolved in water can serve as conductors of electricity. As a result of this, electrochemical processes constantly appear and it serves as one of the main factors that ensure the appearance of corrosion and its acceleration. Fuel oil in raw crude oil contains a significant amount of salts, and these salts have strong corrosive properties. These salts primarily destroy boiler plants, power plants, and tube engines.

Decreased performance of devices (III). The accumulation of salts in the pipelines of the device reduces the passage of oil or gas condensate through the pipeline. This leads to a sharp decrease in production efficiency. If the content of salt chlorides in fuel oil is 800-2200 mg/l, it is necessary to wash 20% of the raw material with calendar time.

Decrease in the range of manufactured products (IV). Salts are mainly concentrated during the driving of fuel oil and tar together with mechanical impurities. According to existing compounds, they are widely used in demulsification and desalination of oil on an industrial scale [1]

Results. Mubarak Oil and Gas Production Department's oil field products contain permanent formation water and its amount increases during the period of exploitation of the fields. As a result of the effect of mineralized formation waters with oil extracted from the well, especially chlorides mineralized formation waters, on the internal corrosion of the equipment, the corrosive aggressiveness increases.

The method of determining the amount of chlorine salts in oil was carried out on the basis of the international standard GOST 21534-76. A 30% solution of carboxymethylcellulose and foaming soap was used as a surfactant for flotation of water-soluble salts. In this experiment, K-1 in the amount of 30 g/t was carried out in a laboratory device in the presence of a demulsifier, we mixed it for 10 minutes with a rotation of 60 rpm. For control , we conducted the experiment in the traditional way by heating the emulsion to 75-85 ⁰C^. It was determined that the desalination obtained in the ratio of 1:50 of the obtained flotation mixture was 92% yield (Table 1).

Table 1.

Changes in the amount of chlorine and alkali salts in the emulsion, oil and formation water during demulsification of oil through a demulsifier

From table -1 apparently as it is, Kokdumalak, Kuruk and South Kemachi mines water - oil emulsions from demulsification after layer in the waters chlorinated and alkaline salts quantity increased. The reason is difficult soluble chlorine salts are highly soluble in the waters of the layer under the action of a deemulgator, and this is very important from a practical point of view for the preparation of oil in the field. [2].

Discussion. Oils prepared for processing in oil fields must fully meet the standards. Oil raw materials extracted in Uzbekistan are divided into three groups according to the amount of water and salts in the composition (Table 2).

Table 2.

Changes in the amount of water and salts in domestic crude oil

Table 2 shows that after treatment with deemulgator, there was a decrease in the amount of mineral salts in local oils. The reason is, the more mineral salts in the oil, the more amount they pass into the composition of the separable water.

Conclusion. Research has shown that low salt content oil was achieved when the starch field treated water-oil emulsions with deemulgators and allowed processing to prepare group II oil instead of group III. This has a significant positive effect on the technical and economic indicators of the enterprise and leads to an increase in the quality of petroleum products produced.

References:

1. Yusupov D., Karimov A.U. Sostoyanie i perspektiva proizvodstva i primenenie ingibitorov korrozii v Respublike. Spravochnik. T.: Standart, 2005, -35 s.
2. Sattorov, M.O. (2018). Vliyanie soley na ispolzovanie nefti i neftyanogo sirya. Nauchniy aspekt, 7(4), g.Samara. OOO “Aspekt”. S. 860-862.