RU2480504C2 - Composition to prevent formation of organic deposits and hydrates in wells and pipelines - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: composition for prevention of formation of organic deposits and hydrates in wells and pipelines, including a depressor, a surfactant and a dissolvent, the depressor is a modified branched polycarboxylate - MBPC, the surfactant is KT-12, and the dissolvent is gas condensate, at the following ratio of components, wt %: MBPC 10 - 15, KT-12 10 - 60, gas condensate - balance.

EFFECT: improved efficiency of a composition and provision of processing performance.

12 ex, 3 tbl

Description

The invention relates to the oil and gas industry and is intended to prevent the formation of organic deposits and hydrates in wells and pipelines, respectively producing and transporting oil or gas condensate, at low temperatures.

The main reason leading to a sharp decrease in the throughput of pipelines and well flow rates is the formation of organic deposits and (or) hydrates, especially at low temperatures.

A known composition for removing and preventing resin-paraffin deposits, containing a mixture of ethoxylated higher alcohols and an aromatic solvent (see AS USSR No. 981335, IPC ⁵ C09K 3/00, E21B 43/00, publ. 15.12.1982).

The disadvantages of this composition are low inhibitory efficacy and lack of dispersing ability.

The closest in technical essence and the achieved result is a paraffin deposition inhibitor adopted as a prototype, including a mixture of hydroxyethylated higher alcohols, sulfonated adducts of the general formula R ₁ SO _m ^- K ⁺ , where R ₁ -C _n H _(2n) -C ₆ H ₄ or R ₁ -C _n H _(2n) -C ₆ H ₄ (OC ₂ H ₄ ) _x , m = 3-4, n = 9-12, x = 6-10, K ⁺ -HN ⁺ R ₂ R ₃ R ₄ where R ₂ -H, R ₃ -R ₄ -C ₂ H ₄ OH, R ₂ -R ₃ -H, R ₄ -C ₂ H ₄ OH, R ₂ = R ₃ = R ₄ -C ₂ H ₄ OH , in the following ratio of components, wt.%: mixture of ethoxylated higher alcohols 4-8, sulfonated adducts 16-32, aromatic solvent - the rest (see RF patent No. 2159788, IPC ⁷ C09K 3/00, E21B 37/06, op Dec. 27.11.2000).

However, this composition, having a high inhibitory effect, slightly lowers the pour point of the medium, i.e. possesses weak depressant properties, and this in turn increases the risk of hydrate formation in wells and process pipelines transporting oil or gas condensate.

The objective of the invention is to create an effective composition (inhibitor) for the treatment of oil and (or) gas condensate in order to prevent the formation of organic deposits and (or) hydrates, which reduces the concentration of these substances in solution by converting them to a solid state on the surface of germ crystals, as well as providing the ability to perform such processing at ambient temperatures up to -22 ° C.

The set task in the composition for preventing the formation of organic deposits and hydrates in wells and pipelines, including a depressant, a surfactant (hereinafter referred to as surfactant) and a solvent, is solved by using a modified branched polycarboxylate (hereinafter MPC) as a depressant, and as a surfactant - KT-12, and gas condensate as a solvent in the following ratio of components, wt.%: MRPK 10-15, KT-12 10-60, gas condensate - the rest.

The claimed composition for preventing the formation of organic deposits and hydrates in wells and pipelines is prepared by mixing the components included in it in a separate container without observing any strict sequence. For example, at first a certain mass of MPC is poured into the vessel, then the calculated amount of CT-12 is added, and gas condensate is added at the end of the preparation. The composition is thoroughly mixed. The finished solution is dosed into wells or pipelines, respectively producing or transporting oil or gas condensate.

As specific components for the study of properties and other technological indicators of the claimed composition can be used:

- MRPK of the Polyex company according to TU 2458-071-53501222-2008 or of another company, for example, LUTENSIT Z 96-70%. The literature (see Falikman VR, et all. New High Performance Polycarboxilate Superplasticizers based on Derivative Copolymers of Maleinic Acid, 6 ™ International Congress GLOBAL CONSTRUCTION, Advances in Admixture Technology, Dundee, 2005, pp. 41-46) describes numerous similar carbochain polymers, in the form of a macromolecule, called “comb-like”.

In its most general form, the chemical composition of modern polycarboxylate superplasticizers (surfactants) of mixed functionality of a new (fourth from the moment of their appearance) generation can be represented by the following structural formula:

KT-12 is a cubic product of the catalytic zeoforming process of gasoline of the KT-12 column of the Sosnogorsk gas processing plant according to TU 7252-024-97152834-2006, which includes cycloalkane and arene carboxylic acids and a hydrocarbon solvent contained in a ratio of 1: 2. The hydrocarbon solvent contained in KT-12 consists of a mixture of branched and aromatic hydrocarbons and is close in composition to AI-92 gasoline. Zeoforming is a catalytic process of processing low-octane gasoline fractions of various origin into high-octane unleaded gasolines on zeolite-containing catalysts (see Senderov E.E., Khitarov N.I. Zeolites, their synthesis and formation conditions in nature. M., 1970. - 165 p. .). The process technology was developed by a group of scientists of STK TSEOSIT CJSC, located on the basis of the Design and Technology Institute of Catalytic and Adsorption Processes on Zeolites of the Siberian Branch of the RAS and the Institute of Catalysis named after Ak. G.K.Boreskova of the Siberian Branch of the Russian Academy of Sciences (see the Techno-economic review “Obtaining high-octane gasolines using the Zeoforming and Zeosin technologies, 2005, parts 1 and 2),

solvent - gas condensate in accordance with OST 51.65-80 “Stable gas condensate”.

Example 1. To 5 g of a mixture of ethoxylated higher alcohols add 95 g of an aromatic solvent (toluene). All are thoroughly mixed (analogue by AS USSR No. 981335).

Example 2. To 10 g of a mixture of ethoxylated higher alcohols add 90 g of an aromatic solvent (toluene). All are thoroughly mixed (analogue by AS USSR No. 981335).

Example 3. To 4 g of a mixture of ethoxylated higher alcohols add 16 g of sulfonated adducts and an aromatic solvent (toluene) to 100 g. All are thoroughly mixed (prototype according to RF patent No. 2159788).

Example 4. To 8 g of a mixture of ethoxylated higher alcohols add 32 g of sulfonated adducts and an aromatic solvent (toluene) to 100 g. All are thoroughly mixed (prototype according to RF patent No. 2159788).

Example 5. To 10 g of MPEC of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add gas condensate to 100 g. All mix thoroughly.

Example 6. To 10 g of MPEC of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add 30 g of CT-12 and gas condensate to 100 g. All are thoroughly mixed.

Example 7. To 1 g MPPK of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add 15 g of CT-12 and gas condensate to 100 g. All are thoroughly mixed.

Example 8. To 1 g of MPEC of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add 30 g of CT-12 and gas condensate to 100 g. All are thoroughly mixed.

Example 9. To 10 g of MPEC of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add 60 g of CT-12 and gas condensate to 100 g. All are thoroughly mixed.

Example 10. To 10 g of MPEC of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add 10 g of CT-12 and gas condensate to 100 g. All mix thoroughly.

Example 11. To 12.5 g MPEC Polyeks company according to TU 2458-071-53501222-2008 or similar, for example, “LUTENSIT Z 96-70%”, add 35 g KT-12 and gas condensate up to 100 g. All carefully mix.

Example 12. To 15 g of MPEC of the company "Polyex" according to TU 2458-071-53501222-2008 or similar, for example, "LUTENSIT Z 96-70%", add 60 g of CT-12 and gas condensate to 100 g. All are thoroughly mixed.

Table 1 shows the results of a study of the analogue, prototype and the claimed composition.

The essence of the study was as follows: on the installation of the “cold rod”, the inventive composition was exposed to gas condensate with a different ratio of components and the inhibition coefficient was determined.

The research method is based on the formation of organic deposits on the “cold rod” when washing it off with hot condensate. The condensate temperature in the installation is + 60 ° С, the temperature of the “cold rod” is -5 ° С, which corresponded to the minimum temperature in the condensate line. The experiment time was 3 hours. After the end of the experiment, the “cold rod" was heated to + 30 ° C and condensate residues were allowed to drain for 10-20 minutes. Then, either “scraping” or increasing the temperature of the deposit was transferred to a previously weighed box and their mass was determined. In the study of the properties of the claimed composition it was introduced into hot condensate at the following concentrations of the constituent components, namely MRPK from 0.001 to 0.02% and CT-12 from 0 to 0.10%.

The calculation of the effectiveness of inhibition was made by the formula

,

,

where K is the coefficient of inhibition,%;

m ₁ - mass on the rod after entering the inventive composition, g;

m ₂ - weight on the rod before entering the inventive composition,

Table 1 Determination of the effectiveness of the claimed composition by the method of "cold rod" Composition Compositions (Examples 1-12) name of the property The concentration of the claimed composition,% The coefficient of inhibition,% one Vuktyl, SP-1 (total flow) 0.01 42.3 2 Condensate West-Soplessk 0.01 45.4 3 Vuktyl, SP-1 (total flow) 0.01 78,2 four Condensate West-Soplessk 0.01 80.3 The claimed composition 5 Vuktyl, SP-1 (total flow) 0.01 82,4 5 Condensate well 129 - Eugid 0.01 81.0 5 Condensate well 140 - Eugid 0.01 70.6 6 Vuktyl, SP-1 (total flow) 0.01 86.6 6 Condensate well 140 - Eugid 0.01 76.5 7 Condensate well 140 - Eugid 0.01 83.7 7 Condensate well 140 - Eugid 0.001 36.3 8 Condensate well 140 - Eugid 0.01 84.6 8 Condensate well 140 - Eugid 0.001 40.1 9 Condensate well 140 - Eugid 0.005 63.9 10 Condensate West-Soplessk 0.01 75.1 eleven Condensate well 143 0.02 87.7 12 Condensate (total flow, S / C + Yugid + Z.S.) 0.01 76.9

As can be seen from the data in table 1, at concentrations above 0.01%, the component of the claimed MRPK composition has sufficient efficiency, and the introduction increases its inhibition coefficient.

The pour point of the samples of gas condensate and oil was determined according to RD 39-0148311-328-88 "Methodology for determining the pour point of paraffin oils".

The essence of the method for determining the depressive properties of the claimed composition is the sequential determination of the pour point of the system without adding the claimed composition and with its addition. The difference in the pour point of the processed oil sample or gas condensate is used to judge the depressant properties of the claimed composition at various concentrations of its constituent components. Before carrying out the studies, the hydrocarbons and the claimed composition are heated to + 60 ° C to transfer the organic deposits contained in the samples to a liquid state.

The studies showed that the decrease in the pour point of oil or gas condensate is 14-28 ° C (see table 2), which mainly affects the decrease in the possibility of hydrate formation in the well-pipeline system.

table 2 The pour point of oil or gas condensates with the addition of the inventive composition Compo
position
composition
(note
Ry 1-12) name of the property Inhibitor Concentration,% Pour point, ° C no additives with the addition one Oil well mouth. 143 - Yugid 0.2 19 17 3 Oil well mouth. 143 - Yugid 0.2 19 16 The inventive composition 5 Oil well 129 - mouth 0.2 17 -5 7 Oil well 129 - mouth 0.2 17 -10 7 Oil well mouth. 60 - Yugid 0.2 2 -23 7 The condensate of the total flow, after the pumping unit - Z.S. 0.2 10 -12 7 Oil common flow guide, metering unit 0.2 8 -12 7 Vuktyl Oil, SP-1, Yugid - Z.S., metering unit, total flow 0.2 6 -12 7 Oil well mouth. 143 - Yugid 0.2 19 5 5 Oil well mouth. 141 - Yugid 0.2 21 one 7 Oil well mouth. 141 - Yugid 0.2 21 -7 7 Oil well mouth. 141 - Yugid 0.05 21 13 7 Oil well mouth. 141 - Yugid 0.01 21 17

The hydrocarbon solvent contained in KT-12 and the gas condensate added to the mixture lower the pour point of the claimed composition from +3 to -12 ... 25 ° C (table 3), which improves the technological parameters of its use.

Table 3 The pour point of the mixture of reagents, where gas condensate is the rest Composition, wt.% Pour point, ° C CT-12 MRPK 10 10 -12 thirty fifteen -17 fifty 10 -22 70 10 -25

Further dilution (introduction of CT-12) reduces the pour point of the mixture, but worsens the inhibitory and depressant properties of the claimed composition.

The claimed invention in comparison with the prototype allows to reduce the viscosity of oil or gas condensate and reduce the pour point, which makes it possible to increase the productivity of pipelines, reduce the loss of heating of the system.

Claims (1)

Composition for preventing the formation of organic deposits and hydrates in wells and pipelines, including a depressant, a surfactant - a surfactant and a solvent, characterized in that a modified branched polycarboxylate - MRPK is used as a depressant, CT-12 is used as a surfactant, and CT-12 is used as a surfactant, and solvent - gas condensate, in the following ratio of components, wt.%:
MRPK 10-15 CT-12 10-60 gas condensate rest