RU2230888C1 - Solid reagent for complex influence on asphalt-resin-paraffin deposits during extraction and transportation of oil - Google Patents

Abstract

FIELD: oil extracting industry.

SUBSTANCE: reagent contains powder-like technical washing substance which includes no less than 4.5 percents of mass of surfactants, no less than 11 percents of mass of phosphorous-acidic salts in P₂O₃ equivalent and no less than 1.7 percents of mass of sodium silicate in SiO₂ equivalent, sulphanol and polyacrylamide with following ratio of ingredients in percents of mass: technical washing substance 60-75; sulphanol 15-30, polyacrylamide - the rest. For removal of asphalt-resin-paraffin deposits it is used in form of 2-3% water solution, and for preventing asphalt-resin-paraffin deposits, it is used by means of placing in a perforated tank surrounded by oil.

EFFECT: asphalt-resin-paraffin deposits may be removed by means of reagent from surfaces of pipes footed by polyethylene, with concurrent increase of effectiveness of prevention of forming of asphalt-resin-paraffin deposits under such conditions, and higher ecological effectiveness.

2 cl, 1 ex, 4 tbl

Description

The invention relates to the field of oil production, in particular to solid reagents with a complex effect on asphaltene-tar-paraffin deposits (AFS), and is intended for the processing of infield and trunk pipelines, mainly lined with polyethylene, with the aim of their comprehensive protection (simultaneous removal of asphaltene-tar and paraffin substances from their surface and prevention of deposits ASPV).

Currently, there are no solid reagents with a complex effect for protecting from ASPO pipes lined with polyethylene.

Known liquid composition for washing asphaltenes, resins and paraffins from metal surfaces with the following content of ingredients, wt.%: Solvent 3.00-52.00; sulfanol 0.25-2.50; sparingly soluble surface-active substance (surfactant) 0.05-0.15 and water - the rest (see ed. certificate of the USSR No. 1114687, class 09 K 3/00, publ. 09/23/84).

Also known is a liquid composition for removing paraffin, containing, wt.%: Nonionic surfactant OP-7 or OP-10 16-35; sulfanol 4.5-10.3 and an aromatic solvent - the rest (see RF Patent No. 2173328, CL 09 K 3/00, 1999).

The main disadvantage of these known composition and composition is their unstable physical condition, namely, it is relatively quickly stratified during storage. And the conditions for oil production are such that, as a rule, more than a month passes from the moment the composition is prepared to remove the paraffin deposit until it is delivered to the field and used.

Another disadvantage of these known composition and composition is their extremely low efficiency of removing paraffin from non-metallic surfaces and their lack of properties to prevent the formation of paraffin. Those. these well-known compositions are not able to provide comprehensive protection against paraffin deposits of surfaces lined with polyethylene.

Closest to the proposed technical solution for the state of aggregation is a composition for the complex effect on produced fluids containing a powdered technical detergent TMS, including at least 4.5 wt.% Surfactants, at least 11 wt.% Phosphoric acid salts in in terms of P ₂ O ₅ and not less than 1.7 wt.% sodium silicate in terms of SiO ₂ , and two organic additives: phosphorus-containing reagent ISB-1 or HEDP and bottoms production of amines C ₁₇ -C ₂₀ in the following ratio of ingredients, wt.%:

Phosphorus-containing reagent ISB-1 or OEDF 12-80

TMS 7-60

VAT residue of the production of amines C ₁₇ -C ₂₀ Else

(see RF Patent No. 2131969, class E 21 B 37/06, 1997). The specified known composition is intended to prevent deposits of salts and ASWA in relation to light, medium and especially heavy oils, while providing a stable supply of inhibitory components of the composition to produced fluids at all possible oil and water ratios.

However, this known composition does not have a complex effect on paraffin, i.e. does not provide simultaneous removal and prevention of paraffin, including from surfaces lined with polyethylene. At the same time, some ingredients (for example, still bottoms from the production of C ₁₇ -C ₂₀ amines) are waste from hazardous industries and, therefore, do not provide an environmentally friendly composition.

The technical result achieved by the proposed solid reagent is to give it the ability to remove paraffin from the surface of pipes lined with polyethylene, while increasing its effectiveness in preventing deposits of paraffin under these conditions.

An additional technical result is to ensure the environmental friendliness of the reagent.

The achievement of this technical result is provided by the proposed solid reagent for the complex effect on asphaltene-tar-paraffin deposits during oil production and transportation, containing a powdered technical detergent TMS, including at least 4.5 wt.% Surfactants, at least 11 wt.% Phosphoric acid salts in terms of P ₂ O ₅ and not less than 1.7 wt.% sodium silicate in terms of SiO ₂ , and organic additives, while the reagent contains sulfanol and polyacrylamide as organic additives in the following the total ratio of ingredients, wt.%:

TMS 60-75

Sulfanol 15-30

Polyacrylamide Else

The proposed solid reagent for removing asphaltene-resin-paraffin deposits is recommended to be used in the form of a 2-3% aqueous solution, and to prevent asphaltene-resin-paraffin deposits, it is recommended to place it in a perforated container washed with oil.

The achievement of the specified technical result was made possible thanks to the combined effect of the ingredients included in the proposed reagent. For example, due to the combined effect of TMS and sulfanol, the ARPD will be easily and completely removed from the polyethylene surface, apparently due to the increased penetrating ability of the molecules of these substances in the crystal lattice of deposits and due to the identical surface-substance organic nature, as a result of which a protective film will be adsorbed on the surface of the polyethylene, preventing paraffin crystals from sticking to this surface, and the presence of polyacrylamide makes this process more efficient due to th enveloping effect.

To obtain the inventive reagent in laboratory conditions, the following substances were used:

powdered technical detergent (TMS) (TU 2499-019-04643756-96);

sodium sulfanol-alkylbenzenesulfonate according to TU 2481-159-00209645-99 with a concentration of the main substance of at least 80%, a yellowish powdery substance;

polyacrylamide (PAA) grades: Praestol 2530, 2530TV, 2540 according to TU 2216-001-40910172-98; Acrylamide polymer anionic AK-642 according to TU 6-02-00209-912-65-99;

technical water;

water produced simultaneously with a density of from 1.005 to 1.170 g / cm ³ .

The possibility of carrying out the claimed invention is confirmed by the following example:

Example. To obtain the inventive solid reagent in the laboratory took 0.6 g of TMS; 0.3 g of sulfanol and 0.1 g of PAA. The powder mixture was mixed and received the claimed reagent.

When conducting laboratory tests were determined:

the degree of dissolution of the inventive solid reagent in waters of various densities;

the degree of paraffin removal from the polyethylene and metal surfaces of the proposed reagent;

the washing ability of the proposed reagent for the removal of paraffin;

paraffin deposition effectiveness.

Tests for the solubility of the inventive solid reagent was carried out in the traditional way, namely by determining the degree of dissolution of various substances. It consists in the following: samples of the inventive solid reagent (1, 2 or 3 g) were placed in conical flasks with water of various degrees of mineralization. Having thus prepared 1-, 2- and 3% aqueous solutions, visual observations were made of the degree of dissolution of the inventive solid reagent. To accelerate the dissolution of the proposed solid reagent in water, it is allowed to heat up to 60 ° C. These tests were necessary to identify the optimal concentrations of aqueous solutions of the reagent when using it to remove paraffin.

The degree of dissolution of the inventive solid reagent in fresh and associated produced waters of different densities are shown in table 1.

The data shown in table 1 show that the inventive solid reagent is well soluble in fresh and slightly mineralized water with a density of up to 1.010 kg / cm ³ , water in a concentration of 2-3%, therefore, a reagent solution of this concentration is preferable when removing paraffin.

Further, in the course of laboratory tests, the washing ability of the inventive solid reagent used in the implementation of the proposed method, and the maximum and optimal ratio of ingredients in it were determined.

The washing ability of the claimed reagent, as well as the effectiveness of the removal of paraffin by the proposed method was determined by the following indicators:

for washing a film of oil;

the magnitude of the dispersion of paraffin in an aqueous solution of the inventive reagent;

by sticking and coating the surface of the paraffin in an environment of an aqueous solution of a reagent;

for washing flasks from paraffin.

During the tests, they used the paraffin deposits of Gozhansky, Alnyashsky and Olkhovsky deposits. More detailed characteristics of the AFS studies used are given in Table 2.

The data obtained during studies on the washing ability of the inventive reagent are shown in table 3.

The data in table 3 show that the inventive solid reagent, when it contains 60-75 wt.% TMS, 15-30 wt.% Sulfanol and 10-15 wt.% PAA, provides for the effective removal of various types of paraffin deposits (washing the paraffin from the walls is 85-100%, which is 15-20% more effective than the prototype).

During laboratory tests, the degree of removal of paraffin from the polyethylene surface of the proposed reagent was determined. To do this, they took polyethylene samples, which were previously degreased and weighed. Then they were layered with AFS, dried for 2 hours and weighed again. After that, the samples were placed for 4 hours in an aqueous solution of a reagent of 2% concentration, then dried for 16 hours at a temperature of 20 ° C and weighed. The difference in weights was used to determine the degree of washing out of the sample from paraffin deposits. The data are shown in table 4.

The data shown in table 4 show that the proposed reagent provides high efficiency removal of paraffin by 90-93% from polyethylene surfaces.

The same studies were carried out on steel plates that simulated a tubing. The data on the washing of paraffin from metal plates by the proposed reagent have the same results in terms of efficiency as the washing of paraffin from polyethylene samples. Thus, the proposed solid reagent can be recommended for use both in producing wells equipped with metal pipes, and in flow lines and pipelines lined with polyethylene.

In the course of laboratory tests, the effectiveness of the proposed and known solid reagent for the prevention of paraffin deposits on the surface of a polyethylene sample was also determined. To do this, fat-free, dried and suspended polyethylene samples were placed in a mixture of an aqueous solution of a solid reagent saturated with paraffin at 50 ° C and held for 4 hours. Then they were taken out, dried, weighed, and the relative effectiveness for preventing paraffin deposits was determined by the degree of sedimentation on them.

The results showed that the proposed solid reagent provides high efficiency for the prevention of paraffin deposition, which is 10-20% higher than that of the solid reagent known from the prior art.

When using the proposed solid reagent in field conditions, it is recommended to use it in the form of an aqueous solution of 2-3% concentration for flushing wells and pipelines from paraffin deposits, and in the form of delivery in a perforated container to prevent deposits from ASPA.

The use of the proposed solid reagent will increase the effectiveness of anti-paraffin control in both polyethylene and metal pipelines, and increase the time between overhauls of wells and the throughput of labor pipelines, and will also increase the profitability of wells.

In the preparation of the inventive reagent, environmentally friendly components are currently being produced in Russia.

The solid state of the proposed reagent provides its high stability and high adaptability when using, which allows to increase the shelf life without changing properties and ease of delivery to the field.

Claims (2)

1. A solid reagent for the complex effect on asphaltene-tar-paraffin deposits during the extraction and transportation of oil, containing a powdered technical detergent TMS, including at least 4.5 wt.% Surfactants, at least 11 wt.% Phosphoric acid salts in terms of P ₂ About ₃ and not less than 1.7 wt.% Sodium silicate in terms of SiO ₂ , and organic additives, characterized in that as organic additives the reagent contains sulfanol and polyacrylamide in the following ratio of ingredients, wt.%: TMS 60-75 Sulfanol 15-30 Polyacrylamide Else 2. The solid reagent according to claim 1, characterized in that it is used in the form of a 2-3% aqueous solution to remove asphaltene-tar-paraffin deposits, and to prevent asphaltene-tar-paraffin deposits by placement in a perforated container washed with oil.

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