EA037393B1 - Method for loss determination during oil cleaning of mechanical impurities in a centrifugal apparatus - Google Patents

Abstract

The invention relates to oil treatment at oil fields, oil refineries and petroleum product transportation systems. The objective of the invention is improving oil quality and properties prior to its transportation, with consideration for quantitative evaluation of oil in-process loss during removal of mechanical impurities using a centrifugal apparatus. The objective of the invention is attained by provision of a method for loss determination during oil cleaning of mechanical impurities using a centrifugal apparatus, comprising oil heating up to a preset temperature and purification, that ensures obtaining of the oil quality with the required concentration of mechanical impurities, wherein the amount of oil lost in the course of centrifuging is determined from the ratio:where Qo is amount of crude oil to be cleaned from mechanical impurities, t; gimp. is concentration of mechanical impurities in oil, %; ko.c. is degree of oil cleaning from mechanical impurities using a centrifugal apparatus, fraction; ko is concentration of oil in the residue when separating mechanical impurities using a centrifugal apparatus, fraction.

Description

The invention relates to the primary preparation of oil in the fields, enterprises of processing and transportation of petroleum products.

There is a known method for determining the loss of oil and oil products from evaporation during storage and transportation in tanks, based on a computational and experimental method for determining its components, in the implementation of which the value of the volume of emissions as a result of the displacement of vapors with air in the process of filling the container with liquid (large breathing) or changes in thermodynamic the state of the air-vapor mixture in the container (small breathing) is determined by calculation [1].

The disadvantage of this method is the impossibility of using it to calculate losses when cleaning oil from mechanical impurities during centrifugation.

There are a number of methods for determining technological losses of oil during collection and preparation at oil production enterprises, during storage in tank farms and during transportation through main pipelines [2, 3, 4].

The disadvantage is that the method for calculating losses when cleaning oil from mechanical impurities during centrifugation is not defined in any of the above methods.

The closest technical solution to the proposed invention is a method for purifying oil from mechanical impurities, including heating and cleaning it in a centrifuge, and at least two measurements of viscosity are made at different temperatures, and the temperature of oil heating, which ensures a given quality of oil is obtained, is determined from the ratio [ five]:

Г = / _О -1.1П (1)

However, the known method does not provide for the determination of oil losses during its cleaning from mechanical impurities in a centrifuge.

The objective of the invention is to improve the quality and properties of oil before transportation, taking into account the quantitative assessment of technological losses of oil when removing mechanical impurities from it using centrifuges.

The problem is solved by the fact that in the method for determining losses during oil purification from mechanical impurities in a centrifuge, including heating it to a certain temperature and purification, which ensures that the quality of oil with the required concentration of mechanical impurities is obtained, the amount of oil that is lost during centrifugation is determined from the ratio:

QqeH Qh X ^ o.n. Snp. / 100 where Qh is the amount of crude oil to be refined from mechanical impurities, t;

g _np - concentration of mechanical impurities in oil,%;

k _o . _n . - degree of oil purification from mechanical impurities in a centrifuge, fraction;

k _H is the concentration of oil in the sediment during the separation of mechanical impurities in a centrifuge, fraction.

Before centrifugation, crude oil is preheated, which leads not only to a decrease in viscosity, but also to a decrease in the stability of the oil, which ensures its deeper purification and, accordingly, increases the productivity of the centrifuge. During this technological process, the following types of oil losses are formed:

a) losses from evaporation of oil heated to a certain temperature during centrifugation;

b) loss of oil in the wet sediment of mechanical impurities.

There are known methods for determining oil losses from evaporation in any containers, and a method for determining oil losses in the wet sediment of separated mechanical impurities during centrifugation must be developed.

The existing equation of the material balance of the filtration process [6] or centrifugation of oil reflects the dependence of the amount of crude oil, refined oil and the amount of wet sediment of mechanical impurities:

(2) where Q _h is the amount of crude oil;

Q _och . _n . - the amount of refined oil;

Q _ow . _oc . - the amount of wet sediment of mechanical impurities.

The amount of oil that is lost in centrifuges during its purification from mechanical impurities (Q _prices ) in the composition of the wet sludge is calculated according to the following formula:

(3) where Q _ow . _oc . - the amount of wet sediment of mechanical impurities remaining after centrifugation; k _H - concentration of oil in the sediment during separation of mechanical impurities in a centrifuge, fraction.

From the formula (3) derive the amount of wet residue (Q _{βΛ oc..)} During centrifugation:

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Qen.oc. Oschen (4)

To determine the amount of refined oil (Q _{04. H.} ), It is necessary to exclude the amount of mechanical impurities from crude oil, which depends on the concentration of impurities in the oil, according to the results of laboratory analyzes, and also take into account the degree of oil purification of a particular centrifuge, according to its technical characteristics.

Qo4.h = Qh- {Qh * to _he * g _np . / 100) (5) where Q _n - the amount of crude oil purified from mechanical impurities; Q _n xg _np / 100xk _{o n} - the amount of mechanical impurities removed from the oil during centrifugation; g _np - concentration of mechanical impurities in oil,%; to _about . _n . - the degree of oil purification from mechanical impurities. Having determined the amount of refined oil (Q _och . _H. ) And the amount of wet residue (Q _Bn .oc.) In the process of centrifugation, the material balance equation (2) will take the form

Qh = [Qh -AQh xk ₀ gnp. 1100)] + Q _yeH / k _n (6)

Hence, the amount of oil losses during its cleaning from mechanical impurities in a centrifuge is calculated:

@ prices Qh K k ^ gnp. / U0 (7)

The claimed method for calculating oil losses during its cleaning from mechanical impurities in centrifuges was tested at an oil production enterprise, which produces oil with a high content of mechanical impurities, as a result of which there is a need for cleaning in centrifuges in the process of preparing oil for transportation.

Losses calculated in this way were included in the general rate of technological oil losses arising in the process of oil production, preparation, storage and transportation at an oil production enterprise.

The proposed technical solution is new and simplified, since the calculations are not cumbersome, and losses can be calculated by several parameters: the concentration of mechanical impurities in the oil, the degree of oil purification in a centrifuge and the concentration of oil in the wet sediment during the separation of mechanical impurities during the operation of centrifuges.

Consider an example of the implementation of the proposed method. The amount of oil that is lost in centrifuges during its cleaning from mechanical impurities was calculated as part of the rate of technological oil losses arising in the process of oil production, preparation, storage and transportation for the Karasu Operating Company in the Misgovdag and Kslamsdin fields.

To bring the quality of crude oil with a concentration of mechanical impurities g _np , = 1.75% into a commercial product with a concentration of mechanical impurities of 0.07%, it is heated before refining the oil in a centrifuge. We calculate the optimal temperature for heating crude oil to obtain a given concentration of mechanical impurities according to the well-known Reynolds formula and formula 1. For the given properties of oil, it must be heated to a temperature of 57 ° C.

1η (ν /%) ₌ 1p (68.9 / 140) ₀₀₃₂ tt _Q 40-18 '

T = i ₀ -i-ln and

= 18 - ί0.032

5920x0.07 ₊₁ p _{140 = 5651}

12-1.5)

The process of oil centrifugation is carried out in an LW520x1290-N1 centrifuge with a degree of oil purification from mechanical impurities to ₀ . _n = (100% -0.07%) / 100% = 0.999.

The amount of oil refined from mechanical impurities Q _n = 178865 tons per year.

After centrifugation, the concentration of oil in the wet sediment of the separated mechanical impurities, according to laboratory studies, is k _n = 0.08.

Substituting the values of g _np , k _he , k _n for a given amount of refined oil heated to a temperature of 57 ° C Q _n = 178865 tons / year into the ratio (7), we obtain the amount of oil lost during its purification in a centrifuge

Que _H ~ Qh hkoi * k _n- x. g _np . / 100 = 178865 x 0.999x 0.08x 1.75 / 100 = 250 tons / year

Thus, technological losses of oil during its purification from mechanical impurities in a centrifuge are equal to 250 t / year, which is 0.14% of the total amount of refined oil.

In comparison with the prototype, in which the problem of only one of the links in the technological chain of the centrifugation process is solved (determination of the optimal temperature for heating oil before its purification), the proposed method solves the final problem of this process, i.e. determination of the value of production losses of oil when cleaning it from mechanical impurities in a centrifuge.

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Literature

1. RF patent No. 2541695, MKI G01L 11/00, publ. 2015 g.

2. Guidelines for determining technological oil losses during production, technologically related to the adopted scheme and technology of field development and construction. Ministry of Energy of Russia, 2009

3. Guidelines for determining the technological losses of oil from their technological reservoirs. Ministry of Energy of Russia, 2015

4. Methodological recommendations for determining technological losses of oil and oil products during transportation by main pipeline transport of the Ministry of Energy of Russia, 2012

5. RF patent No. 2196805, MKI C10 G31 / 06, C10 G31 / 10, publ. 2003 r.

6.https: //helpiks.org/4-91288.html

Claims (1)

CLAIM A method for determining losses when cleaning oil from mechanical impurities in a centrifuge, including heating it to a certain temperature and purifying it, ensuring that the quality of oil with the required concentration of mechanical impurities is obtained, characterized in that in the process of centrifugation, the amount of oil losses in the wet sediment of separated mechanical impurities is determined from the ratio: QifeH Qh * ^to ON * K * gnp. / 10 where Qh is the amount of crude oil to be refined from mechanical impurities, t; g _np - concentration of mechanical impurities in oil,%; k ₀ . _H. - degree of oil purification from mechanical impurities in a centrifuge, fraction; k _H is the concentration of oil in the sediment during the separation of mechanical impurities in a centrifuge, fraction.