WO2025240302A1

WO2025240302A1 - Control of sulfate-reducing bacteria under anaerobic conditions using glutaraldehyde and peroxymonosulfate

Info

Publication number: WO2025240302A1
Application number: PCT/US2025/028858
Authority: WO
Inventors: Bei Yin; Philip MAUN
Original assignee: Lanxess Corp
Current assignee: Lanxess Corp
Priority date: 2024-05-14
Filing date: 2025-05-12
Publication date: 2025-11-20
Anticipated expiration: 2026-11-14

Abstract

Disclosed herein are methods for controlling anaerobic microorganisms, especially sulfate -reducing bacteria, in anaerobic environments or under anaerobic conditions in water-containing systems using a combination of glutaraldehyde and an alkali metal or alkaline earth metal peroxymonosulfate.

Description

TITLE

Synergistic Control of Anaerobic Microorganisms Using Glutaraldehyde and Peroxymonosulfate

FIELD OF INVENTION

The present disclosure relates to controlling anaerobic microorganisms under anaerobic conditions in a water-containing system, such as in the oil and gas industries, as well as other industrial processing industries.

BACKGROUND OF INVENTION

Protecting water-containing systems from anaerobic microbial contamination is critical to the efficiency and success of many industrial processes in which the extraction, production, processing, transportation, storage or disposal of water-containing fluids are common, particularly in the oil and gas industries. Contamination from anaerobic microorganisms commonly occurs during these operations, such as in downhole oil or gas reservoirs, near wellbore areas, produced water, injection water, deaeration towers, transmission pipelines, bottoms of vessels or tanks, etc. Certain anaerobic bacteria known as sulfate reducing bacteria (SRB) naturally utilize sulfate as the terminal electron acceptor during anaerobic respiration through dissimilatory sulfate reduction, resulting in hydrogen sulfide (H₂S) production as a metabolic by-product. H₂S is a toxic gas which can sour oil and gas, corrode pipelines and storage tanks and cause deposits of iron sulfide. Metabolic activity of anaerobic microorganisms, especially of SRB, can cause microbiologically influenced corrosion, which may pose severe operational, environmental and safety problems.

WO 96/14092 Al discloses microbiocidal combinations comprising (i) an oxidant selected from the group of mono- or diperoxyorganic acids, halogen dioxides, monopersulfates, halogens, halogen releasing compounds, perborates, peroxides, persulfates, permanganates, percarbonates, ozone, and water soluble salts thereof, and mixtures thereof, and (ii) a non-oxidizing microbiocide selected from the group consisting of glutaraldehyde, limonene, bis (trichloromethyl) sulfone, 2-(decylthio)- ethanamine, dodecylguanidine hydrochloride, 2-(2-bromo-2-nitroethyl) furan, poly(oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride), alkyl dimethyl benzyl ammonium chloride, alkylamidopropyl propylene glycol dimethyl ammonium chloride phosphate, 2,4,4'trichloro- 2'-hydroxydiphenyl ether, tetrakishydroxylmethyl phosphonium sulfate, tributyltetradecyl phosphonium chloride, 2-bromo-2-nitropropane-l, 3-diol, and 2,2-dibromo-2-nitroethanol and sanguinaria extract. The reference, however, teaches that “not all oxidants provide enhanced biocidal activity when used in combination with non-oxidizing biocides . . . [i]n fact, some oxidants are actually antagonistic when used in combination with non-oxidizing biocides, and result in less biocidal effectiveness than the use of either component alone.” No experimental testing in WO 96/14092 Al involved any SRB or any other anaerobic microorganisms under anaerobic conditions. Aerobic and anaerobic microorganisms differ not only in their metabolic pathways but also in the nature of their intermediate and final metabolic products. For example, SRB produce hydrogen sulfide, a reactive species known to interact with both oxidizing agents and certain non-oxidizing biocides. Such interactions can reduce the speed and efficacy of these treatment agents. The potential combination of oxidizing agents with non-oxidizing biocides and their outcomes for use against SRB remain unknown and unpredictable from the disclosure in WO 96/14092 Al.

There remains a need for the development of biocidal treatment methods and materials that can provide improved control against anaerobic microorganisms, particularly SRB, in anaerobic environments or under anaerobic conditions in water-containing systems.

SUMMARY OF INVENTION

The present inventors have discovered that the biocide glutaraldehyde and an alkali metal or alkaline earth metal peroxymonosulfate are synergistic for controlling anaerobic microorganisms, particularly sulfate-reducing bacteria (SRB), in anaerobic environments or under anaerobic conditions.

Provided is a method of controlling anaerobic microorganisms, preferably SRB, in an anaerobic environment or under anaerobic conditions in a water-containing system, the method comprising treating the water-containing system with an amount of glutaraldehyde and an amount of an alkali metal or alkaline earth metal peroxymonosulfate. In one aspect, the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate are synergistic for killing or reducing the concentration of SRB. In another aspect, the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate are synergistic for inhibiting the growth of SRB. Preferably, the weight ratio of the glutaraldehyde to the alkali metal or alkaline earth metal peroxymonosulfate is a ratio determined to have a bacterial reduction Synergy Index of less than 1 against Desulfovibrio alaskensis, more preferably a bacterial reduction Synergy Index of less than or about equal to 0.9 or, in particular, less than or about equal to 0.8.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “synergistic” and the like mean that the desired antimicrobial effect of the relevant combination is greater than the additive effect of each component. A synergistic effect can be shown, for example, based on the calculation of a Synergy Index value, such as determined via certain antimicrobial activity testing. For example, the Synergy Index may be determined according to the equation: Synergy Index =Q_a /Q_A +Q_b /Q_B, where Q_A is the quantity (ppm) needed of substance A alone to produce the endpoint, Q_B is the quantity (ppm) needed of substance B alone to produce the endpoint, Q_a is the quantity (ppm) of substance A needed when it is used in combination with substance B to produce the endpoint, and Q_b is the quantity (ppm) of substance B needed when it is used in combination with substance A to produce the endpoint. As in the Examples of the present disclosure, the endpoint may be the minimum concentration required to achieve a certain level of bacterial reduction (e.g., essentially complete bacterial reduction) in a given culture medium. A Synergy Index less than one (<1) means synergism exists, a Synergy Index of one (1) means an additive effect exists, and a Synergy Index greater than one (>1) means antagonism exists.

As used herein, the term “anaerobic microorganisms” refers to microorganisms (preferably, SRB) in anaerobic environments that can grow under conditions with little or no oxygen due to their ability to metabolize nutrients and carry out biological processes in the absence of oxygen.

As used herein, the term “anaerobic environments” or “anaerobic conditions” refers to environments or conditions having little or no oxygen such that the environment or conditions are insufficient to sustain aerobic metabolism. It shall be understood that an “anaerobic environment” or “anaerobic conditions” can be generally widespread, such as in downhole formations, reservoirs, or wells or can be localized, such as within biofihns (e.g., in nearbore areas) or in transmission pipelines or in the bottoms of vessels or equipment (e.g., storage or holding tank bottoms), etc.

As used herein, “control” or “controlling” refers to killing or reducing the concentration of or inhibiting the growth of anaerobic microorganisms (e.g., SRB).

As used herein, the term “effective amount” and the like refer to an amount to provide a desired effect to control anaerobic microorganisms (e.g., SRB).

The methods of the present disclosure are useful for controlling anaerobic microorganisms in anaerobic environments or under anaerobic conditions in water-containing systems. The method comprises treating the water-containing system with an amount of glutaraldehyde and an amount of an alkali metal or alkaline earth metal peroxymonosulfate. As demonstrated herein, the present inventors have discovered that this combination is synergistic for controlling anaerobic microorganisms, particularly sulfate-reducing bacteria (SRB), in anaerobic environments or under anaerobic conditions.

The alkali metal or alkaline earth metal peroxymonosulfate is chemically representable as M_aH_b(SO₅)_c where M is an alkali metal in Group la of the Periodic Table or an alkaline earth metal in Group lb of the Periodic Table where a, b, and c are integers. Integers a, b, and c satisfy the relationship na + b equals 2c where n is an integer equal to 1 for an alkali metal or equal to 2 for an alkaline earth metal. Integer b can be 0 such that hydrogen is absent in the H_b term of M_aH_b(SO₅)_c.

The alkali metal peroxymonosulfates include alkali metal hydrogen peroxymonosulfates and dialkali metal peroxymonosulfates. Preferred alkali metals are sodium, potassium, lithium or any combination thereof, more preferably potassium. For primary alkali metals potassium, sodium and lithium, the alkali metal peroxymonosulfates are potassium hydrogen peroxymonosulfate (KHSO₅), dipotassium peroxymonosulfate (K₂SO₅), sodium hydrogen peroxymonosulfate (NaHSO₅), disodium peroxymonosulfate (Na₂SO₅), lithium hydrogen peroxymonosulfate (LiHSO₅), and dilithium peroxymonosulfate (Li₂SO₅). Preferred alkaline earth metals are calcium, magnesium or a combination thereof. For primary alkaline earth metals magnesium and calcium, the alkaline earth metal peroxymonosulfates are magnesium peroxymonosulfate (MgSO₅), magnesium dihydrogen diperoxymonosulfate (MgH₂(SO₅)₂), calcium peroxymonosulfate (CaSO₅), and calcium dihydrogen dipcroxymonosulfatc (CaH₂(SO₅)₂).

Preferably, the alkali metal or alkaline earth metal peroxymonosulfate is potassium hydrogen peroxymonosulfate (KHSO₅). In preferred embodiments, the potassium hydrogen peroxymonosulfate is provided as a component of a multiple salt (i.e., the multiple salt comprises potassium hydrogen pcroxymonosulfatc). That is, in such embodiments, the method of the present disclosure includes treating the water-containing system with a multiple salt, wherein the multiple salt provides the amount of the potassium hydrogen peroxymonosulfate (KHSO₅). Preferably, the multiple salt is a potassium monopersulfate which is characterized by a hydrogen-bonded structure of potassium hydrogen peroxymonosulfate (KHSO₅), potassium hydrogen sulfate (KHSO₄) and potassium sulfate (K₂SO₄), commonly referred to aass aa triple salt and can be represented by the general formula (KHSO₅)_x(KHSO₄)_y(K₂SO₄)_z for which the sum of mole fractions x, y, and z equals 1. The active oxygen component of the potassium monopersulfate triple salt is potassium hydrogen peroxymonosulfate (KHSO₅). Such triple salts are commercially available or can be prepared by known methods. The mole fraction x is often at least about 0.40, more preferably at least about 0.43, or at least about 0.46. In general, the mole fractions may be represented by the following exemplary ranges: x is about 0.43-0.64, y is about 0.15-0.43, and z is about 0.15-0.43, particularly where x is about 0.46-0.64, y is about 0.15-0.37, and z is about 0.15-0.37.

In a particular example, the potassium monopersulfate used in the presently disclosed methods is commonly represented by the formula 2KHSO₅.KHSO₄.K₂SO₄ (corresponding to theoretical mole fractions x, y, z above of 0.5, 0.25 and 0.25, respectively) and which are particular implementations of the more general triple salt formula above. These embodiments have a theoretical active oxygen content of 5.2%, and commercial versions thereof often have an active oxygen content close to this theoretical value, such as an active oxygen content of at least about 4.5%, for example an active oxygen content of about 4.7%. Reference herein to the potassium monopersulfate triple salt of the formula 2KHSO₅.KHSO₄.K₂SO₄ is intended to be inclusive of such embodiments having an active oxygen content close to the theoretical active oxygen content of 5.2%, such as the commercial versions thereof. The potassium monopersulfate triple salts of the present disclosure may have an active oxygen content greater than the about 4.7% active oxygen content which is typically found in commercially available potassium monopersulfate triple salts. Such triple salts may be prepared as known in the art, such as described in U.S. Pat. No. 7,090,820.

In general, the potassium monopersulfate triple salts of the present disclosure have an active oxygen content of at least about 4.0%, preferably at least about 4.5%, or more preferably at least about 4.7%. For example, the active oxygen content may be from about 4.0%, from about 4.5% or from about 4.7% to about 6.8%, to about 6.2%, to about 5.5% or to about 5.2%.

The peroxymonosulfate or multiple salt containing the same, such as a potassium monopersulfate triple salt, may be in a solid (e.g., crystalline) form or in a formulated solid form or liquid form, such as a liquid solution (e.g., an aqueous solution).

Glutaraldehyde and the alkali metal or alkaline earth metal pcroxymonosulfatcs, including multiple salts thereof, such as potassium monopersulfate triple salts, are commercially available and/or can be prepared by well known techniques. For example, a potassium monopersulfate triple salt commonly represented by the formula 2KHSO₅.KHSO₄.K₂SO₄ is available commercially under the brand name OXONE®.

The anaerobic microorganisms controlled in accordance with the presently disclosed methods typically comprise anaerobic bacteria, such as anaerobic bacteria of the Deltaproteobacteria class. The methods of the present disclosure are especially relevant for controlling sulfate reducing microorganisms, particularly sulfate reducing bacteria (SRB). Examples of genera of such SRB include Desulfovibrio, Desulfocarbo, Desulfobacterium, Desulfobulbus, Desulfoarculus, Desulf obacter, Desulfococcus, Desulf otomaculum, Desulfosporomusa, Desulfosporosinus , Desulfobaculum, Desulf ocurvibact er, Desulf ocurvus, Desulf ohalovibrio, Desulf olutivibrio, Desulfohalobium, Desulf onatronospira, Desulf onatronovibrio, Desulf othermus, Desulfonauticus, Desulf overmiculus , Desulfohalophilus, Desulfatibacillum, Desulfomonas, Thermodesulfovibrio, among others. Often, the SRB is of the genus Desulfovibrio, such as Desulfovibrio alaskensis, Desulfovibrio vulgaris, Desulfovibrio longus, Desulfovibrio desulfuricans, Desulfovibrio gabonensis, and other species of the Desulfovibrio genus. The anaerobic microorganisms may include methanogenic archaea, sulfate-reducing archaea, iron- reducing bacteria, thiosulfate-reducing bacteria and other anaerobic microorganisms. In general, the anaerobic microorganisms targeted for control by the presently disclosed methods are strict anaerobes, which can grow and carry out metabolic processes in only anaerobic environments.

The methods of the present disclosure are useful for treating a variety of water-containing systems containing anaerobic environments or anaerobic conditions, such as underground water-containing systems, closed water-containing systems, and lower or bottom parts of open water-containing systems. The presently disclosed methods are especially useful for treating water-containing systems in energy- related (e.g., oil and gas) extraction, production, refining, storage, transportation and disposal applications, such as those comprising oil and/or natural gas formations or reservoirs, injection fluids, fracturing fluids, production fluids, source fluids for waterflooding or hydraulic fracturing, fluids in oil and/or gas separation, transmission or storage, etc. The water-containing system, for example, may include hydrocarbon oil and/or natural gas having an aqueous phase associated therewith. The watercontaining system may include other types of fuel, such as hydrogen (e.g., in the transportation or storage of hydrogen, such as subsurface storage). The water-containing system may be a wellbore, downhole formation, reservoir or well (e.g., a disposal well), or infrastructure or equipment used in the extraction, production, processing, transportation, storage or disposal of a fluid, such as crude or processed oil or natural gas or other types of fuel. In particular, for example, the water containing system may comprise at least one of injection water, formation water, produced water, flowback water, waste water, cooling water or source water, such as pond water or holding tank water. It shall be understood that the water-containing system may comprise more than one of such fluids. The wellbore may be, for example, an injection well, production well, disposal well or fracturing well. Typically, the downhole formation or reservoir is an oil and/or natural gas formation or reservoir.

Treating the water-containing system may comprise adding or delivering the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate to a fluid which contacts or flows or is stored within the wellbore, the downhole formation, reservoir or well or the infrastructure or equipment. For example, the fluid to which the glutaraldehyde and peroxymonosulfate may be added or delivered (i.e., the fluid comprising the glutaraldehyde and peroxymonosulfate) may contact or flow or be stored within a wellbore, such as wellbore casings, liners, screens, etc. or mineral surfaces. The fluid may contact or flow or be stored within a downhole formation, reservoir or well, including, e.g., pore spaces in the fonnation, such as relevant to the flow of injection, formation, flowback and/or production fluids. The fluid may contact or flow or be stored within infrastructure or equipment, such as pipelines (e.g., pipelines connecting tanks, vessels or processing units), tubing, such as downhole injection tubing, vessels, such as transportation, cargo or storage vessels, underground structures, holding tanks, mixing tanks, flow lines, injection lines, production lines, separators, scrubbers (e.g., a deaeration tower), etc. The infrastructure or equipment may, for example, transport the fluid from one point to another, such as an oil and/or gas pipeline. The infrastructure or equipment can be used in petroleum (e.g., oil or natural gas) extraction, such as a wellhead, and/or as part of a petroleum (e.g., oil and/or gas) refinery, such as a pipeline, a separation vessel, a storage tank, etc. The fluid to which the glutaraldehyde and peroxymonosulfate may be added or delivered may include gas hydrocarbons, liquid hydrocarbons or a combination thereof. The fluid to which the glutaraldehyde and peroxymonosulfate may be added or delivered may include other types of fuels, such as hydrogen. In many embodiments, the fluid comprises natural gas, a liquid hydrocarbon or a combination thereof. The fluid may be, for example, a crude oil based fluid. In many embodiments, the fluid comprises at least one of injection water, formation water, produced water, flowback water, waste water, cooling water or source water, such as described herein.

In general, the water-containing system is treated with a weight ratio of the glutaraldehyde to the alkali metal or alkaline earth metal peroxymonosulfate, such as potassium hydrogen peroxymonosulfate (KHSO₅), (or a multiple salt thereof, such as a potassium monopersulfate triple salt) of from about 100:1 (e.g., from about 50:1) to about 1:200 (e.g., to about 1: 100), such as from about 100:1 to about 1:100, from about 80:1 to about 1 :80, or from about 50: 1 to about 1 :50. The water-containing system may be treated, for example, with a weight ratio of glutaraldehyde to the alkali metal or alkaline earth metal peroxymonosulfate (preferably potassium hydrogen peroxymonosulfate (KHSO₅)) of from about 52:1 to about 1:40. The water-containing system may be treated, for example, with a weight ratio of glutaraldehyde to a potassium monopersulfate triple salt, such as described herein, of from about 26: 1 to about 1:80.

The present application is not limited to any specific manner or technique for treating the watercontaining system with the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate. In general, the water-containing system is treated such that the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate are or become mixed with or dissolved within a fluid for providing treatment at the site of interest. For example, the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate may be added or delivered in the desired ratio and amount to a fluid that contacts or flows or is stored within the wellbore, the downhole formation, reservoir or well or the infrastructure or equipment. The water-containing system can be treated with the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate at substantially the same time. For example, they can each be individually provided concurrently with one another or they can be provided as a mixture to treat the water-containing system, such as by adding or delivering the materials or the mixture to a fluid which contacts or flows or is stored within a wellbore, downhole formation, reservoir or well or infrastructure or equipment, as described herein. Or the water-containing system can be treated with the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate at substantially the same time by adding or delivering the materials in parallel or one after the other in the desired ratio and amounts with little delay (i.e., about 5 minutes or less) in between. In other embodiments, the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate are added or delivered to the water-containing system at different times (i.e., with a delay in between of more than 5 minutes, for example a delay of about 10 minutes or more, about 20 minutes or more, about 30 minutes or more, about 1 hour or more, about 3 hours or more, about 6 hours or more or about 12 hours or more). Such delay in between is typically no more than 72 hours, preferably about 48 hours or less, more preferably about 24 hours or less, in particular, about 18 hours or less, about 12 hours or less, about 8 hours or less, about 6 hours or less, about 3 hours or less or about 1 hour or less. The glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate may be added continuously or in batch (e.g., an intermittent batch treatment, whether during operation or during a shutdown period), or a combination thereof (such as continuous treatment during operation and a batch treatment during a shutdown period). For example, the water-containing system may be treated with the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate in a single dose (or “slug”) or may be added in multiple slugs. The glutaraldehyde and the alkah metal or alkaline earth metal peroxymonosulfate may alternatively be continuously added to the watercontaining system in order to maintain a desired concentration and ratio of components.

The exact manner of adding or delivering the glutaraldehyde and the alkali metal or alkaline earth metal pcroxymonosulfatc will depend on various factors, such as the form or formulation of the materials, the particular system and the site of interest. The glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate can be added at a point in a flow line upstream from the point at which controlling anaerobic microorganisms in an anaerobic environment or under anaerobic conditions is desired. The methods of the present disclosure can be used to control anaerobic microorganisms over time, for example, as associated with the movement of a fluid through the system or as the process(es) taking place in the system evolves. The glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate may be added to the water-containing system using mechanical equipment such as chemical injection pumps, piping tees, injection fittings, quills, and the like. The glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate maybe added or delivered using an umbilical line or using a capillary injection system.

The water-containing system can be treated with the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate to achieve a desired effective amount or concentration in the watercontaining system, and the treatment can occur for a desired period of time (including at desired frequencies or intervals). The skilled artisan can select final working amounts or concentrations, including desired treatment time periods, intervals and frequencies, of the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate necessary to provide the desired antimicrobial effect. In general, the combined concentration of the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate (preferably potassium hydrogen peroxymonosulfate (KHSO₅)) in the watercontaining system (such as in a fluid which contacts or flows or is stored within a wellbore, downhole formation, reservoir or well or infrastructure or equipment, such as described herein) may be in the range of from about 10 ppm or from about 50 ppm to about 10000 ppm, such as from about 10 ppm, from about 50 ppm or from about 100 ppm to about 5000 ppm or from about 10 ppm, from about 50 ppm, or from about 100 ppm to about 1000 ppm. In general, the combined concentration of the glutaraldehyde and a potassium monopersulfate triple salt, such as described herein, in the watercontaining system (such as in a fluid which contacts or flows or is stored within a wellbore, downhole formation, reservoir or well or infrastructure or equipment, such as described herein) is in the range of from about 20 ppm or from about 100 ppm to about 20000 ppm, such as from about 20 ppm, from about 100 ppm or from about 200 ppm to about 10000 ppm or from about 20 ppm, from about 100 ppm or from about 200 ppm to about 2000 ppm. It shall be understood that the foregoing ranges are exemplary only. Other amounts or concentrations may be applied. The water-containing systems may contain or be treated with other agents in addition to the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate, such as scale and corrosion inhibitors, oxygen scavengers, and/or additional biocides.

Preferably, the weight ratio of the glutaraldehyde to the alkali metal or alkaline earth metal peroxymonosulfate (e.g., potassium hydrogen peroxymonosulfate (KHSO₅)) is a ratio determined to have a bacterial reduction Synergy Index of less than 1 against Desulfovibrio alaskensis. In further preferred embodiments, the alkali metal or alkaline earth metal peroxymonosulfate (e.g., potassium hydrogen pcroxymonosulfatc (KHSO₅)) and glutaraldehyde combination have a bacterial reduction Synergy Index (SI) of less than or equal to 0.8 against one or more species of SRB, in particular, e.g., against one or more bacteria of the Desulfovibrio genus, such as against Desulfovibrio alaskensis. In certain of such embodiments, the weight ratio of the glutaraldehyde to the alkali metal or alkaline earth metal peroxymonosulfate is from about 52:1 to about 1:40.

In other preferred embodiments, the water-containing system is treated with a potassium monopersulfate triple salt, such as any embodiment as such described herein, wherein the triple salt provides the potassium hydrogen peroxymonosulfate (KHSO₅). Preferably, the weight ratio of the glutaraldehyde and the potassium monopersulfate triple salt is a ratio determined to have a bacterial reduction Synergy Index of less than 1 against Desulfovibrio alaskensis. In further preferred embodiments, the glutaraldehyde and potassium monopersulfate triple salt combination have a bacterial reduction Synergy Index (SI) of less than or equal to 0.8 against one or more species of SRB, in particular, e.g., against one or more bacteria of the Desulfovibrio genus, such as against Desulfovibrio alaskensis. In certain of such embodiments, the weight ratio of the glutaraldehyde to the potassium monopersulfate triple salt is from about 26: 1 to about 1:80.

As used herein, the articles “a”, “an”, and “the” preceding an element or component of the invention are intended to be nonrestrictive regarding the number of instances (i.e., occurrences) of the element or component. Therefore “a”, “an”, and “the” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.

As used herein, the term “comprising” means the presence of the stated features, integers, steps, or components as referred to in the claims, but that it does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. The term “comprising” is intended to include embodiments encompassed by the terms “consisting essentially of’ and “consisting of’. Similarly, the term “consisting essentially of’ is intended to include embodiments encompassed by the term “consisting of’.

As used herein, the term “about” modifying the quantity of an ingredient or reactant employed refers to variation in the numerical quantity that can occur, for example, through typical measuring and liquid handling procedures used for making concentrates or use solutions in the real world; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the ingredients employed to make the compositions or carry out the methods; and the like.

Where present, all ranges are inclusive and combinable. For example, when a range of “1 to 5” is recited, the recited range should be construed as including ranges “1 to 4”, “1 to 3”, “1-2”, “1-2 & 4-5”, “1-3 & 5”, and the like.

When a parameter is given either as a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. The scope of the invention is not intended to be limited to the specific values and examples as recited in the specification.

EXAMPLES

Inside an anaerobic chamber, potassium hydrogen peroxymonosulfate (KHSO₅) - provided in the form of a potassium monopersulfate triple salt (available under the brand name OXONE® and commonly represented by the formula 2KHSO₅.KHSO₄.K₂SO₄) - glutaraldehyde, and combinations of glutaraldehyde and the potassium monopersulfate triple salt at different concentrations were prepared in deionized water that had been stored under an anaerobic environment. The solutions were inoculated with a suspension of D. alaskensis ATCC 14563 to a final 10^7-8CFU/mL D. alaskensis concentration. After the mixtures were incubated at 30°C for 48 hours under anaerobic conditions, the biocidal efficacy was determined by minimum tested biocide concentrations for 99.999% viable cell reduction in the mixtures. Table 1 summarizes the efficacy of each treatment and the Synergy Index of each combination on a basis of potassium hydrogen peroxymonosulfate (KHSO₅) concentration. Table 2 summarizes the efficacy of each treatment and the Synergy Index of each combination on a basis of potassium monopersulfate triple salt concentration. As shown in the Tables, potassium hydrogen peroxymonosulfate synergistically enhances the biocidal efficacy of glutaraldehyde against sulfate reducing bacteria over a broad range of ratios of each substance.

The Synergy Index (SI) was determined according to SI = Ca/CA + Cb/CB, where

Ca: Concentration of substance A required to achieve a >99.999% bacterial reduction when used in combination,

CA: Concentration of substance A required to achieve a >99.999% bacterial reduction when used alone,

Cb: Concentration of substance B required to achieve a >99.999% bacterial reduction when used in combination, CB: Concentration of substance B required to achieve a >99.999% bacterial reduction when used alone.

A Synergy Index less than one (<1) shows synergy, a Synergy Index of one (1) shows an additive effect, and a Synergy Index greater than one (>1) shows antagonism.

Table 1.

Table 2.

Claims

What is claimed is:

1. A method of controlling sulfate-reducing bacteria under anaerobic conditions in a watercontaining system, comprising treating the water-containing system with an amount of glutaraldehyde and an amount of an alkali metal or alkaline earth metal peroxymonosulfate, wherein the weight ratio of the glutaraldehyde to the alkali metal or alkaline earth metal peroxymonosulfate is a ratio determined to have a bacterial reduction Synergy Index of less than 1 against Desulfovibrio alaskensis.

2. The method of claim 1, wherein the alkali metal or alkaline earth metal pcroxymonosulfatc is potassium hydrogen peroxymonosulfate (KHSO₅).

3. The method of claim 1 or 2, wherein the water-containing system comprises at least one of injection water, formation water, produced water, flowback water, waste water, cooling water or source water.

4. The method of any preceding claim wherein the water-containing system is a wellbore, downhole formation, reservoir or well, or infrastructure or equipment used in the extraction, production, processing, transportation, storage or disposal of a fluid.

5. The method of claim 4, wherein treating the water-containing system comprises adding or delivering the glutaraldehyde and the alkali metal or alkaline earth metal peroxymonosulfate to a fluid that contacts or flows or is stored within the wellbore, the downhole formation, reservoir or well or the infrastructure or equipment.

6. The method of claim 5, wherein the fluid that contacts or flows or is stored within the wellbore, the downhole formation, reservoir or well, or the infrastructure or equipment comprises natural gas, a liquid hydrocarbon or a combination thereof.

7. The method of any one of claims 5 or 6, wherein the fluid that contacts or flows or is stored within the wellbore, the downhole formation, reservoir or well, or the infrastructure or equipment comprises at least one of injection water, formation water, produced water, flowback water, waste water, cooling water or source water.

8. The method of any one of claims 4-7, wherein the infrastructure or equipment comprises a pipeline, storage vessel, tank, tubing, flow line, injection line, production line, wellhead, separator or scrubber.

9. The method of any preceding claim, wherein the sulfate-reducing bacteria are of the Desulfovibrio genus.

10. The method of any one of claims 2-9, wherein the weight ratio of the glutaraldehyde to the potassium hydrogen peroxymonosulfate (KHSO₅) is a ratio determined to have a bacterial reduction Synergy Index of less than or equal to 0.8 against Desulfovibrio alaskensis.

11. The method of any one of claims 2-10, wherein the weight ratio of the glutaraldehyde to the potassium hydrogen peroxymonosulfate (KHSO₅) is from about 52:1 to about 1:40.

12. The method of any one of claims 2-11, wherein the method comprises treating the watercontaining system with a potassium monopersulfate triple salt to provide the amount of the potassium hydrogen peroxymonosulfate (KHSO₅), and wherein the triple salt further comprises KHSO₄ and K₂SO₄.

13. The method of claim 12, wherein the potassium monopersulfate triple salt is represented by the formula (KHSO₅)_x(KHSO₄)_y(K₂SO₄)_z for which the sum of mole fractions x, y, and z equals 1, and x is 0.43-0.64, y is 0.15-0.43, and z is 0.15-0.43.

14. The method of claim 12, wherein the potassium monopersulfate triple salt is represented by the formula 2KHSO₅.KHSO₄.K₂SO₄.

15. The method of any one of claims 12-14, wherein the weight ratio of the glutaraldehyde to the potassium monopersulfate triple salt is a ratio determined to have a bacterial reduction Synergy Index of less than or equal to 0.8 against Desulfovibrio alaskensis.

16. The method of claim 15, wherein the weight ratio of the glutaraldehyde to the potassium monopersulfate triple salt is from about 26:1 to about 1:80.