RU2228432C1 - Compound for removal of asphalt-resin-paraffin sedimentations - Google Patents

Abstract

FIELD: oil extracting industry. SUBSTANCE: compound has, in percents of mass: hydrocarbon fraction at 70-165 centigrade, received from benzine fraction of reforming process with addition of 15.9-17.3% dicyclopentadiene, or said fraction, received by means of rectification of liquid pyrolysis products, which has 15.9-17.3% cyclopentadiene and dicyclopentadiene mixture - 98.8-99.2, surface-active substance - 0.3-0.5 and polar nonelectrolyte - 0.5-0.7. EFFECT: increased speed of asphalt-resin-paraffin sedimentations removal and increased dissolvent capacity. 4 tbl

Description

The invention relates to oil production, in particular to compositions for removing asphalt-resin-paraffin deposits (AFS), and can be used to remove them in the bottomhole formation zone, in oilfield equipment, tanks and oil pipelines.

For the removal and prevention of paraffin, many compounds are known, consisting, as a rule, of their three components: aliphatic and aromatic hydrocarbons and surfactants (ionic or nonionic, or mixtures thereof). The combination of aliphatic and aromatic hydrocarbons is achieved both by compounding and by using certain fractions of hydrocarbons. For the introduction into the composition of the paraffin wax remover by the method of compounding aliphatic hydrocarbons, a hexane fraction is used (US Pat. No. 2009155, MKI C 09 K 3/00, publ. 03/15/94), straight-run gasoline (US Pat. No. 2098433, MKI C 09 K 3/00, Е 21 В 37/06, publ. 10.12.97), gasoline is unstable (US Pat. No. 2129583, MKI C 09 K 3/00, Е 21 В 37/06, publ. 04/27/99), gasoline is a raw material for pyrolysis ( Pat. No. 2005117, MKI C 09 K 3/00, publ. 12/30/93), aromatic - heavy oil solvent (Pat. No. 2009155, MKI C 09 K 3/00, E 21 V 36/00, publ. 15.03. 94), ethylbenzene and butylbenzene fractions, light pyrolysis resin (US Pat. No. 2098433, MKI C 09 K 3/00, E 21 B 37/06, publ. 10.12.97).

In addition to aliphatic and aromatic hydrocarbons, in some cases unsaturated hydrocarbons such as piperylene and isoprene are also introduced into the composition of paraffin paraffin removers (US Pat. No. 2149982, MKI E 21 B 37/06, C 09 K 3/00, publ. 27.05.00) , still bottoms of rectification of styrene (US Pat. No. 2175376, IPC S 09 K 3/00, publ. 10.27.01).

Due to the fact that the paraffin deposits of even one field differ substantially in composition, none of the proposed methods is universal with respect to the paraffin deposits of a number of fields.

Closest to the essential features of the present invention is the composition according to patent No. 2129583 (IPC C 09 K 3/00, E 21 B 37/06, publ. 03/27/99), containing aliphatic and aromatic hydrocarbons, polar non-electrolyte, surfactant -emulsifier and pH regulator in the following ratio of ingredients, vol.%:

aliphatic hydrocarbons 36-78

aromatic hydrocarbons 20-60

polar non-electrolyte 0.5-4

demulsifier surfactant 0.01-1

pH regulator rest

A disadvantage of the known composition is the low removal efficiency of asphalt-resin-paraffin deposits (paraffin deposits) from production wells of deposits characterized by a high content of high molecular weight paraffins, resins and asphaltenes. In addition, the known composition is characterized by insufficiently high dissolution capacity of paraffin.

Based on the foregoing, the problem arises of creating, on the basis of available raw materials, an effective scavenger for paraffin wax with a high content of high molecular weight paraffins, resins and asphaltenes. The technical result is the acceleration of the removal process of the above paraffin deposits while increasing the capacity of the solvent, i.e. the ability of the solvent to dissolve and disperse a larger number of deposits, which helps to reduce the consumption of solvent.

The specified technical result is achieved by the fact that in the known composition for removing asphalt-resin-paraffin deposits, including a hydrocarbon fraction, a surfactant and a polar non-electrolyte, according to the invention, a hydrocarbon fraction of 70-165 ° C. obtained from the gasoline fraction of the reforming process is used, s adding to it 15.9-17.3% of dicyclopentadiene or the specified fraction obtained by rectification of liquid pyrolysis products, which includes 15.9-17.3% of a mixture of cyclopentadiene and dicyclopentadiene, in the following ratio, wt.%

Hydrocarbon fraction 70-165 ° C, obtained

from the gasoline fraction of the reforming process, with

the addition of 15.9-17.3% dicyclopentadiene

or the specified fraction obtained by distillation

liquid pyrolysis products, which includes

15.9-17.3% mixture of cyclopentadiene and

dicyclopentadiene 98.9-99.2

Surfactant 0.3-0.5

Polar non-electrolyte 0.5-0.7

It is advisable to use as a surfactant substances selected from the group: OP-7, OP-10, Synterol AFM-12.

An aliphatic alcohol selected from the group: methyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol can be used as a polar nonelectrolyte.

The hydrocarbon fraction with a boiling point of 70-165 ° C can be obtained in two ways:

a) by isolating it from the gasoline fraction of reforming units.

In this case, to achieve the specified technical result, it is necessary to add dicyclopentadiene in the amount of 15.9-17.3 wt.%, Which is produced by industry according to TU 2416-024-05766801-94;

b) rectification of liquid pyrolysis products produced according to TU 38.400262-144-93, in this case, this fraction contains a mixture of unsaturated cyclic hydrocarbons - cyclopentadiene and dicyclopentadiene in the amount of 15.9-17.3 wt.%.

Non-ionic surfactants OP-7 and OP-10 are oil-like liquid from light yellow to light brown in color and are produced according to GOST 8433-81. Non-ionic surfactant neonols - ethoxylated alkyl phenols based on propylene trimers are light yellow oil-like liquid and are produced in accordance with TU 2483-077-05766801-98 of seven grades (neonol AF 9-4, neonol AF 9-6, neonol AF 9-9 , neonol AF 9-10, neonol AFB-10, neonol AF 9-12, neonol AFB -12).

Synterol AFM - 12-sodium salt of carboxymethylated hydroxyethylated isononylphenols is a paste from white to light yellow or gray, manufactured in accordance with TU 38.602-22-44-93.

Polar non-electrolyte is represented by aliphatic alcohols: methyl (GOST 6995-77), isopropyl (GOST 9805-84), n-butyl (GOST 5208-81), isobutyl (GOST 9536-79).

Achievements of the specified technical result are explained as follows.

The hydrocarbon fraction of 70-165 ° C obtained by the above methods contains paraffinic, aromatic and unsaturated hydrocarbons, including cyclic, cyclopentadiene and dicyclopentadiene in ratios that allow the most effective effect on paraffin, with a high content of high molecular weight paraffins, resins and asphaltenes. Unsaturated cyclic hydrocarbons - cyclopentadiene and dicyclopentadiene contained in the fraction of 70-165 ° C, accelerate the removal of paraffin deposits and increase the capacity of the solvent. A polar non-electrolyte in combination with these hydrocarbons enhances the above effect. Surfactants act on ASPO conglomerates, disperse them, increasing the surface available for interaction with the solvent and make it impossible to re-merge them.

Thus, a new set of components of the fraction 70-165 ° С, which contain, along with aliphatic and aromatic hydrocarbons, additional unsaturated cyclic hydrocarbons (cyclopentadiene and dicyclopentadiene) with surfactants and polar nonelectrolyte, allows to obtain a new technical result - acceleration of the ARPD removal process with simultaneous an increase in solvent capacity, resulting in a decrease in solvent consumption.

Example 1 (preparation of the proposed composition in the laboratory). Composition 1.

In a 250 ml flask, 99.2 g of a hydrocarbon fraction with a boiling point of 70-165 ° C obtained by distillation of liquid pyrolysis products containing 15.9 g of cyclic unsaturated compounds are added, 0.3 non-ionic surfactant OP-10 is successively added to it. and 0.5 g of methanol. The resulting mixture was stirred and closed with a ground stopper.

Other formulations with different ratios of ingredients were similarly prepared.

When conducting laboratory tests, the following properties of the proposed composition were investigated: the effectiveness of the removal of paraffin deposits, the dissolution capacity. Data on the composition of the used paraffin are shown in table 1. Data on the content of ingredients in the proposed compositions are shown in table 2.

Example 2. The proposed compositions were tested for the effectiveness of the removal of paraffin according to the method STP-03-153-2001 “Laboratory technique for determining the dissolving and removing ability of ASPO solvents” (method B).

To test the AFS samples, the characteristics of which are given in Table 1, balls 10–12 mm in diameter were formed, which, after weighing on an analytical balance, were placed on a metal mesh into 25 ml measuring cylinders, into which 10 ml of the studied solvent was previously poured. The tests were carried out for 2 hours, and every 15-30 minutes, changes in the physical state of the deposits were recorded. If after 2 hours deposits remained on the grid, they were removed from the solvent, dried and weighed on an analytical balance.

The calculation of the effectiveness of the solvent was carried out according to the formula:

where m ₁ is the mass of deposits after the experiment, g;

m is the mass of deposits taken for the experiment, g.

The results are shown in tables 3 and 4.

Example 3. The capacity of the dissolution or saturation of the solvent of the ARPD by the proposed method (composition) was determined by the same method (method B) as follows. A precisely weighed amount of AFS weighing 2 g was placed on a metal mesh with a mesh size of 2-4 mm ^2. Then, the mesh with deposits was placed in a 25 ml measuring cylinder, in which the test solvent with a volume of Y ₁ (10 ml) was poured and left for 30 minutes. After the deposition time, the mesh was removed, inspected, then again lowered into the cylinder and solvent Y ₂ (5 ml) was added again. After 30 minutes, the mesh with deposits was removed, inspected, then again lowered into the cylinder, adding a new portion of the solvent with a volume of Y ₃ (5 ml). The experiment was continued until complete dissolution (dispersion) of deposits.

The capacity of the solvent (saturation of paraffin) was determined by the formula:

where m is the mass of the sample, g;

V is the volume of solvent (V1 + V2 + ... + Vn) cm ³ ;

1000 - conversion factor in kg / m ³ .

Similarly, the dissolution capacity of each composition was determined with respect to the AFS subjects. The results are shown in tables 3 and 4. As can be seen from these tables, for the effective removal of paraffin paraffin four types requires no more than 2 hours. Moreover, as shown by experiments, after 1.5 hours, all types of paraffin deposits are removed by the proposed compounds by more than 70%. As for the composition of the prototype, for the effective removal of the four types of AFS requires more than 2 hours, and after 2 hours, the removal efficiency does not exceed 60%. Moreover, the capacity of the known composition in relation to the ARPD of all four types is 2-2.5 times lower than in the proposed solvents.

Example 4 (industrial example).

Well 2802 of the Arlanskoye field is included in the stock of wells complicated by paraffin treatment (formation CII; perforation interval 1455.2-1460.0; fluid flow rate - 11 m ³ / day; oil flow rate 8.7 m ³ / day; water cut 11%; dynamic level - 287 m; inter-treatment period - 3 days).

These deposits are observed in the range of 200-600 m, their mass averages 200-250 kg. The composition of AFS is as follows:

paraffins 41.20%

resin 15.60%

asphaltenes 39.60%.

On the aforementioned well, the proposed composition was tested (composition No. 5) and the composition of the prototype as follows. After crimping the solvent supply line, 2 m ^{3 of the} proposed composition was pumped into the annulus. Through a tanker and a pump, the CA-320 circulated with constant recording of the discharge pressure and sampling. Using pressure stabilization and an express method for determining solvent saturation, the degree of purification of the production string walls from ASPO was determined. Similarly, we tested the composition of the prototype.

The analysis of the results showed that, ceteris paribus, the solvent of the prototype was saturated after 5 washing cycles, and the proposed composition after 10 cycles, that is, after 5 washing cycles, the solvent of the prototype did not work, and the proposed solvent continued to saturate, which, naturally, involves reducing its consumption. Experience has shown the consumption of solvent according to the prototype in an amount of 4 m ³ , and the proposed solvent in an amount of 2 m ³ . The time of the technological operation using the proposed solvent is 1.5 times less than the same time of the solvent according to the prototype.

Thus, the proposed composition for the removal of paraffin deposits, having high dissolution efficiency, can be used for wells in most deposits with paraffin deposits, characterized by a high content of high molecular weight paraffins.

Claims (1)

Composition for removing asphalt-resin-paraffin deposits, including a hydrocarbon fraction, a surfactant, a polar non-electrolyte, characterized in that the hydrocarbon fraction contains a hydrocarbon fraction of 70-165 ° C obtained from the gasoline fraction of the reforming process, with the addition of 15.9-17, 3% dicyclopentadiene or the specified fraction obtained by rectification of the liquid pyrolysis products, which includes 15.9-17.3% of a mixture of cyclopentadiene and dicyclopentadiene, in the following ratio, wt.%: Hydrocarbon fraction 70-165 ° C, obtained from the gasoline fraction of the reforming process, with the addition of 15.9-17.3% dicyclopentadiene or the specified fraction obtained by distillation liquid pyrolysis products, which 15.9-17.3% of a mixture of cyclopentadiene and dicyclopentadiene 98.8-99.2 Surfactant 0.3-0.5 Polar non-electrolyte 0.5-0.7