RU2532019C1 - Agent for neutralising hydrogen sulphide and inhibiting growth of sulphate-reducing bacteria - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to an agent which includes, wt %: an organic base and/or alkali metal hydroxide 0.03-20, a quaternary ammonium salt 0.3-30, polyethylene glycol 0.01-5 and hemiformal (and) lower aliphatic alcohol(s) - the balance.

EFFECT: high biocidal activity and reactivity with respect to hydrogen sulphide, effective protection of equipment from corrosion.

4 cl, 3 tbl, 22 ex

Description

The invention relates to chemical reagents, in particular to reagents for neutralizing hydrogen sulfide and light mercaptans, inhibiting the growth of sulfate-reducing bacteria (SBA) in oilfield environments and protecting equipment from corrosion, and can be used in the oil and gas industry.

Known chemicals for inhibiting the growth of SVB and inhibiting corrosion, which are the product of the interaction of a 30-40% solution of formaldehyde - formalin with ammonia in a molar ratio of 1.6-3: 1 or the products of the interaction of formalin with ammonia and monoethanolamine in a molar ratio of formaldehyde: ammonia: amine 1: (0.05-0.4) :( 0.1-0.9), respectively (RU 2186957, RU 2191849).

These reagents also have the properties of a catalyst for hydrogen sulfide and light mercaptans, i.e. are reagents of complex action, combining the properties of a bactericide and a neutralizer of corrosive sulfur compounds. However, the known reagents are not effective enough and require relatively high dosages when used both as a bactericide (not less than 75 mg / l) and a neutralizer (not less than 5 g / g hydrogen sulfide).

A known composition for neutralizing hydrogen sulfide, inhibiting the growth of SVB and inhibiting corrosion, including the product (s) of the interaction of formaldehyde with monoethanolamine (65-90%), sodium or potassium hydroxide (0.1-1%) and tertiary amino alcohol and / or lower aliphatic alcohol (RU 2228946).

The disadvantages of the known composition are insufficiently high efficiency, low thermochemical stability and decreased activity during storage.

Also known is a composition for neutralizing hydrogen sulfide and methyl, ethyl mercaptans in commercial oil, which is a mixture of hemiformal with an aromatic hydrocarbon (RU 2478687). Moreover, as an aromatic hydrocarbon, it contains benzene, toluene, xylenes, diethylbenzenes in an amount up to 30%.

The disadvantages of this composition are the low biocidal activity to SVB and the rate of neutralization of hydrogen sulfide in oil-water emulsions.

Known complex reagent for cleaning liquid and gaseous media from hydrogen sulfide and mercaptans with the properties of a disinfectant, which is a mixture of 1,3,5-triazine-1,3,5-triethanol of the general formula C ₉ H ₂₁ N ₃ O ₃ - 48-52 % and impurities of 2-dimethylaminoethanol, dimethoxymethane, 2-butanone, methylpropyl ether, 1,3-dimethoxy-2-propanol, diethyl-1,2-ethanediamine and water - up to 100% (RU 2453582).

The disadvantages of this reagent are the duration of the synthesis process (8-12 hours at 50-60 ° C in the presence of a specially developed catalyst of an alkaline nature) and insufficiently high efficiency when used both as a neutralizer (at least 4 g / g hydrogen sulfide) and bactericide (not less than 100 mg / l).

Closest to the proposed invention is a hydrogen sulfide neutralizer comprising hemiformal (s) alcohols C ₁ -C ₅ (75-99.5%) and an organic base (RU 2466175). In an advantageous embodiment, it further comprises an alkali metal hydroxide in the following ratio of components, wt.%:

Hemiformal (s) 85-98 Alkali metal hydroxide 0.1-1 Organic base Rest

Moreover, as an organic base, it mainly contains a tertiary amine and / or quaternary ammonium base, or a mixture of a tertiary amine with primary and secondary amines.

The specified reagent-neutralizer provides effective neutralization of hydrogen sulfide and light mercaptans at low specific costs (2-3 g / g of hydrogen sulfide). It also has biocidal activity against SVB. However, it is not effective enough as a bactericide (the required specific consumption for complete suppression of the growth of SVB is at least 75 mg / l). Another disadvantage of this reagent is the insufficiently high rate of neutralization of hydrogen sulfide in oilfield environments, in particular in oil-water emulsions (oil well production), which requires ensuring a long contact time of the neutralizer with the purified feedstock, which is not always feasible in existing oil treatment plants.

The task of the invention is the creation of an effective reagent with a complex action based on hemiformal, which has higher biocidal activity with respect to SVB and reactivity to hydrogen sulfide. The invention also solves the problem of intensifying the process of neutralizing hydrogen sulfide in oilfield environments, in particular in oil-water emulsions, by increasing the rate of neutralization reaction.

The problem is solved in that the reagent for neutralizing hydrogen sulfide and inhibiting the growth of sulfate-reducing bacteria, including hemiformal (s) of lower aliphatic alcohol (s) and an organic base and / or alkali metal hydroxide, additionally contains a nitrogen-containing cationic surfactant (cationic surfactant), mainly quaternary ammonium salt (HOUR), and polyethylene glycol (PEG) in the following ratio of components, wt.%:

Organic base and / or hydroxide alkali metal 0.03-20 Quaternary ammonium salt 0.3-30 Polyethylene glycol 0.01-5 Hemiformal (s) of lower aliphatic alcohol (s) Rest

Moreover, as a quaternary ammonium salt, it mainly contains chloride salts (chlorides of quaternary ammonium compounds) produced by the industry as marketable products (HOUR in commodity form). In a preferred embodiment, as a quaternary ammonium salt for the manufacture of the proposed reagent, a KATAPAV C substance is used according to TU 2482-003-04706205-2004, which is a 50-80% alcohol solution of alkylbenzyl dimethylammonium chlorides or KATAPAV according to TU 2482-008-04706205- 2004, or Catamine AB according to TU 9392-003-48482528-99, or KSINAL according to TU 9392-001-76639615-06, which are about 50% aqueous solution of alkyl dimethylbenzylammonium chlorides, or ALKAPAV C according to TU 2482-004-04706205- 2005, which is an alcohol solution of alkyltrimethylammonium chlorine Dov, or SEPTAPAV XC according to TU 2482-021-04706205-2005, which is an alcoholic solution of didecyldimethylammonium chloride, or mixtures thereof, or their foreign analogues, for example, VKS brand 80%. The indicated HOUR solutions are intended for use as a raw material (active base) in the production of detergents, disinfectants, textile auxiliary substances, household chemical goods, antiseptic preparations for preserving wood, processing leather, fur, etc. It is also known to use HOUR as a reagent for inhibiting the growth of SVB and hydrocarbon-oxidizing bacteria (BDS) and protecting equipment from corrosion (SU 1570999, RU 2122108, etc.).

As an organic base, the proposed reagent mainly contains a tertiary amine or a mixture of a tertiary amine with primary and / or secondary amines. Moreover, as a tertiary amine, it preferably contains triethanolamine, dimethylethanolamine, diethylethanolamine, dimethylbenzylamine, C ₂ -C ₄ trialkylamines, C ₈ -C ₁₄ dimethylalkylamines or a mixture thereof, or a mixture of mono-, di- and triethanolamines. As the hemiformal of lower aliphatic alcohol, it predominantly contains the hemiformal of methanol and / or ethanol.

PEG-4 (TU 6-13-115-97), PEG-9 (TU 6-14-714-79), PEG-13 (TU 6-14-909-80), PEG-35 and PEG-35 polyethylene glycols proposed for use (TU 6-14-719-82), obtained by the interaction of ethylene oxide with ethylene glycol, are colorless or yellowish liquids without mechanical impurities and are intended for use as a solvent, plasticizer and modifier in the production of polyester fibers, viscose, pharmaceuticals, etc.

It was found that the additional introduction of cationic surfactants, in particular HOUR, and polyethylene glycols (PEG) into the reagent in the optimal ratios found leads to an increase in its reactivity with respect to hydrogen sulfide and the rate of neutralization of hydrogen sulfide in water-oil emulsions, as well as its bactericidal activity in relation to the SVB. Moreover, the increase in the rate of neutralization of hydrogen sulfide in oil-water emulsions is explained by the fact that the water-oil (hydrocarbon) system is heterophasic and in this case the cationic surfactant (HOUR) and PEG perform the function of a catalyst for the interphase transfer of hydrophilic (water-soluble) hemiformals to the oil phase, where the main amount of hydrogen sulfide. It should be noted that quaternary phosphonium (and other onium) salts can also be used as an interphase catalyst in the composition of the proposed reagent, however, they are scarce and expensive products.

An increase in the bactericidal activity of the reagent with the additional introduction of QAS is due to the appearance of a synergistic effect of suppressing the growth of SVB. It was found that the addition of QAS hemiformal to alkaline solutions leads to a sharp increase in bactericidal activity. In this case, a synergistic effect is observed in a wide range of ratios of the components of the mixture, and the greatest effect is at a concentration of HOUR (in commodity form) from 10 to 50%. In addition, the addition of HOURs in an amount of up to 25-50% also leads to an increase in the protective anticorrosive effect of the reagent in oilfield environments. However, the addition of HOUR in amounts of more than 30% in this case is impractical due to a noticeable decrease in the hydrogen sulfide neutralizing ability of the reagent and its specific consumption for neutralizing hydrogen sulfide. It should be pointed out that the proposed reagent may additionally contain a bactericidal preparation of bacteriostatic action, for example, Bacticide brand (according to TU 2484-010-05744685-96) based on ethanolamine trimer or Aminocide (according to TU 88 of the Ukrainian SSR 192.112-90) based on ethanolamine condensation products with carbamide and formaldehyde. An additional introduction to the reagent of a bactericidal preparation of bacteriostatic action of the Baktsid or Aminocide brand in an amount of up to 15-20% allows to obtain an effective biocidal composition with an extended bactericidal action, suitable for protection against microbial damage to organic environments, such as drilling fluids and other organic-based process fluids .

The proposed composition is prepared by mixing the starting components. Its main component, hemiformals, is obtained by known methods by reacting gaseous monomeric formaldehyde or paraformaldehyde (paraform) with lower aliphatic alcohols, mainly methanol and / or ethanol (Ogorodnikov S.K. Formaldehyde. M .: Chemistry. 1984. P. 95-97, 150, 174). To increase the yield of the target product, it is advisable to carry out the reaction of their interaction in an alkaline medium (at pH not lower than 8), i.e. in the presence of an alkaline catalyst. Moreover, as an alkaline catalyst, it is advisable to use an organic base (preferably a tertiary amine) and / or alkali metal hydroxide (RU 2466175). Then, a cationic surfactant, preferably HOUR in commercial form, and polyethylene glycol (PEG), as well as a bactericidal preparation of bacteriostatic action of the brand Baktsid or Aminotsid (in case the obtained reagent is intended, are additionally introduced into the obtained hemiformals containing an organic base and / or alkali metal hydroxide. for use as a long-acting bactericide).

The proposed composition under normal conditions is a mobile liquid from colorless to yellow, with a density in the range of 0.90-1.08 g / cm ³ , a pH of 8-12 and a pour point below minus 45 ° C.

The invention is illustrated by the following specific, but not limiting examples of obtaining the proposed complex reagent and testing it for effectiveness.

Example 1. Obtaining the proposed reagent. In a reaction flask equipped with a stirrer, a thermometer and a reflux condenser, 33 g of methanol, 9.9 g of triethanolamine (TEA) were charged and 37 g of crystalline paraformaldehyde (paraform) was added with stirring. The resulting suspension is stirred at a temperature of 55-60 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. The molar ratio of formaldehyde: methanol in the reaction mixture is 1.1: 1. According to published NMR spectroscopy data (HPLC. 1979. No. 12, p. 2725-2730), in the interaction of formaldehyde with methanol in this molar ratio, a mixture of mono-, di-, tri- and tetrahemoformals of methanol of the general formula CH ₃ -O- (CH ₂ O) _n H, where n = 1-4. Moreover, the content of mono-hemiformal methanol (methoxymethanol) of the formula CH ₃ —O — CH ₂ —OH in the reaction mixture is more than 50%. Then, 20 g of Quaternary ammonium salt (HOUR) in the commercial form of KATAPAV C.80 brand, 0.1 g of PEG-13 polyethylene glycol are added to the resulting reaction mixture and stirred until a homogeneous product is obtained. The product thus obtained, which is a mixture of hemformal formulas of methanol, amine, QAS and PEG, is used as a complex reagent to neutralize hydrogen sulfide, light mercaptans, and suppress the growth of SVB in oilfield media.

Example 2. In the reaction flask of Example 1, 50 g of ethanol, 4.5 g of TEA are charged and 0.1 g of sodium hydroxide and 40 g of paraform are introduced with stirring. The resulting suspension is stirred at a temperature of 65-70 ° C until the paraform is completely dissolved with the formation of ethanol hemiformals. Then, 5 g HOUR in the marketable form of KATAPAV C.80 brand, 0.4 g of PEG-9 polyethylene glycol are introduced into the resulting reaction mass and mixed until a homogeneous product is obtained. The resulting product, which is a mixture of hemiformals of ethanol, amine, QAC and PEG, is used as a complex reagent.

Example 3. In the reaction flask of Example 1, 38 g of methanol are charged and 1 g of potassium hydroxide and 47 g of paraform are introduced with stirring. The resulting suspension is stirred at a temperature of 45-50 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. Then 13 g of KATAPAV S.80 brand HOUR, 1 g of PEG-35 grade polyethylene glycol are introduced into the obtained reaction mixture and stirred until a homogeneous product is obtained.

Example 4. In the reaction flask of Example 1, 35 g of methanol are charged and 0.1 g of sodium hydroxide, 4.9 g of dimethylethanolamine (DMEA) and 40 g of paraform are introduced with stirring. The resulting suspension is stirred at a temperature of 50-55 ° C until complete dissolution of the paraform with the formation of hemiformals of methanol. Then, with stirring, 18 g of HOUR brand KATAPAV C.80, 2 g of polyethylene glycol PEG-4 brand are introduced and mixed until a homogeneous product is obtained.

Examples 5-10. Samples of reagent No. 5-10 receive similarly and in the conditions of example 4, using other brands of HOUR and amines and changing the ratio of components. The component composition of the reagent samples obtained in examples 1-10 are shown in table 1.

Example 11. Testing the proposed complex reagent on the effectiveness of the neutralization of hydrogen sulfide in an oil-water emulsion. 0.09 g of the catalyst of Example 1 is introduced into a thermostated reaction flask with a stirrer, then 100 g of an oil-water emulsion containing 0.031 wt.% (310 ppm) hydrogen sulfide and 8 wt.% Water are charged. The mass ratio of the catalyst: hydrogen sulfide in the reaction mixture is 2.9: 1, i.e. the specific consumption of the catalyst (consumption coefficient) is 2.9 g / g of hydrogen sulfide. Then the oil-water emulsion with the introduced catalyst is stirred at a temperature of 50 ° C for 1 h and put on the sludge of emulsion water. After settling water and cooling to room temperature, a quantitative analysis of the oil phase is carried out for the content of residual hydrogen sulfide and the degree of neutralization of hydrogen sulfide is calculated. Moreover, the degree of neutralization of hydrogen sulfide is 97%.

Examples 12-21. Tests of the samples of the proposed reagent according to examples 2-10 and the known reagent-neutralizer (prototype) are carried out similarly and in the conditions of example 11. The results of determining the degree of neutralization of hydrogen sulfide by the proposed and known reagents are shown in table 1.

Example 22. Test reagent for bactericidal activity. Laboratory tests of reagent samples in examples 1-9 on the effectiveness of suppressing the growth of SSCs are carried out according to the well-known method “Assessment of infection of oilfield media and the bactericidal action of reagents with respect to sulfate-reducing bacteria. Laboratory, bench and pilot tests. ” RD 03-00147275-067-2001. Ufa DOOO BashNIPI-Neft LLC ANK Bashneft. 2001. The quantitative composition of SVB is determined by the method of limiting 10-fold dilutions using Postgate culture medium (OST 39-151-83).

The active accumulative culture of SVB is isolated from the commercial fluid of the Gremikhinsky oil field. After diluting the SSC, the sample is reseeded 3 more times in fresh culture medium. For testing, a culture of an SVB of 4-5 days old is used, giving blackening in 24 hours at a dosage of 1 cm ³ in a nutrient medium. Into a series of labeled glass penicillin vials with a deoxygenated model of produced water, a 1 cm ^{3 of} CFS storage culture is introduced with a sterile syringe and the test reagent is dosed in an amount that provides the required concentration in mg / L. The vials are mixed and incubated for 24 hours at 20-22 ° C, after which 1 cm ^{3 of the} sample treated with the reagent is introduced into the Postgate medium and thermostated at 32-35 ° C. For each reagent concentration, 3 parallel tests are performed. As a control, use similar samples without the addition of a reagent and with the addition of a reagent prototype. Thermostatically controlled vials at 32-35 ° C are observed for 15 days, noting the appearance of a black color. The effectiveness of the bactericidal action of the reagent is evaluated by the appearance or absence of hydrogen sulfide. The presence of hydrogen sulfide is determined by the formation of a black precipitate of iron sulfides. Effective are those reagents that provide complete (100%) inhibition of the growth of SSC at low dosages. In this case, the nutrient medium containing iron sulfate remains transparent or only slightly colored. Table 2 presents comparative test results with the prototype.

The proposed reagent is tested for the effectiveness of its protective action against corrosion in accordance with the "Methodology for assessing the corrosiveness of oilfield environments and the protective effect of corrosion inhibitors using corrosion meters" RD 39-3-611-81. Ufa VNIISPTneft. 1982. The protective effect of the reagent is determined in the inhibited (with the addition of the test reagent) standard and hydrogen sulfide-containing solution according to GOST 9.506-87. As an aggressive environment, a reservoir water model with a density of 1.12 g / cm ³ and a hydrogen sulfide concentration of 100 mg / l is used. Table 3 presents comparative results of the corrosion test with the prototype.

The data presented in table 1 show that the proposed reagent in comparison with the known one has a higher reactivity with respect to hydrogen sulfide and provides a higher degree of neutralization of hydrogen sulfide in oilfield environments (oil-water emulsions). From the data presented in table 2, it can be seen that the proposed reagent, in comparison with the known one, has a higher effect of suppressing the growth of SVB and provides complete suppression of the growth of SVB at low specific costs (25-50 mg / l). The data presented in table 3 show that the proposed reagent also has a high effect of inhibiting hydrogen sulfide corrosion, therefore, it can be used as a complex action reagent.

table 2 Sample Number Bactericidal effect against SVB at a dosage of reagent, mg / l one hundred 75 fifty 25 one complete suppression complete suppression complete suppression complete suppression 2 complete suppression complete suppression complete suppression incomplete suppression 3 complete suppression complete suppression complete suppression complete suppression four complete suppression complete suppression complete suppression complete suppression 5 complete suppression complete suppression complete suppression complete suppression 6 complete suppression complete suppression complete suppression complete suppression 7 complete suppression complete suppression complete suppression complete suppression 8 complete suppression complete suppression complete suppression complete suppression 9 complete suppression complete suppression complete suppression complete suppression 11 (prototype) complete suppression complete suppression incomplete suppression incomplete suppression

Table 3 Sample Number Reagent concentration, mg / l The degree of protection against corrosion,% one fifty 90 four fifty 96 5 fifty 93 7 fifty 95 11 (prototype) fifty 70

Claims (4)

1. A reagent for neutralizing hydrogen sulfide and inhibiting the growth of sulfate-reducing bacteria, including hemiformal (s) of lower aliphatic alcohol (s), an organic base and / or alkali metal hydroxide, characterized in that it additionally contains a nitrogen-containing cationic surfactant, mainly quaternary ammonium salt, and polyethylene glycol in the following ratio, wt.%:
Organic base and / or alkali metal hydroxide 0.03-20 Quaternary ammonium salt 0.3-30 Polyethylene glycol 0.01-5 Hemiformal (s) of lower aliphatic alcohol (s) Rest 2. The reagent according to claim 1, characterized in that as a quaternary ammonium salt, it mainly contains chloride salts in commodity form. 3. The reagent according to claim 1, characterized in that as an organic base it mainly contains a tertiary amine or a mixture of a tertiary amine with primary and / or secondary amines. 4. The reagent according to claim 1, characterized in that as the semiformal of lower aliphatic alcohol, it mainly contains the semiformal of methanol and / or ethanol.