Compositions and methods for synergistic control of microorganisms in anaerobic environments

Abstract

Disclosed herein are methods for controlling microorganisms in anaerobic environments using a synergistic combination of 2,2-dibromo-3-nitrilopropionamide (DBNPA) and peroxy monosulfate. Compositions containing the synergistic combination are also provided.

Description

[0001] Docket No.: P003 OOO86-WO-PCT

[0002] TITLE

[0003] Compositions and Methods for Synergistic Control of Microorganisms in Anaerobic Environments

[0004] FIELD OF INVENTION

[0005] The present disclosure relates to controlling microorganisms on surfaces and in a wide variety of watercontaining systems under anaerobic conditions.

[0006] BACKGROUND OF INVENTION

[0007] Anaerobic microbial contamination poses significant challenges across various industrial processes in which the extraction, production, processing, transportation, storage or disposal of water-containing fluids are common, particularly in the oil and gas production industries. Such contamination can lead to biofouling, corrosion and the formation of hazardous biofilms, which can result in equipment failure, reduced efficiency, increased costs and other negative effects which significantly impact the performance and longevity of industrial processes. In the oil and gas industries, severe operational and economic impacts can occur due to the proliferation of anaerobic microorganisms in water-containing systems, such as in wells, downhole environments, injection water, produced water, source water, near wellbore areas, pipelines, equipment, functional fluids, etc. Anaerobic microorganisms, such as anaerobic sulfide-producing microorganisms are most commonly found in downhole environments, certain near wellbore areas, transmission pipelines, deaeration towers, bottoms of vessels or tanks, etc. For example, especially problematic arc certain anaerobic bacteria known as sulfate reducing bacteria (SRB), which 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. ELS is a toxic gas which can sour oil and gas. corrode pipelines and storage tanks and cause deposits of iron sulfide.

[0008] Traditional methods of microbial control often involve the use of chemical biocides. However, biocides may require high dosing regimens to maintain efficacy. There remains a need for continued exploration of improved and more sustainable chemical solutions to control anaerobic microorganisms, particularly sulfide-producing microorganisms, such as SRB.

[0009] SUMMARY OF INVENTION

[0010] The present inventors have discovered that the biocide 2, 2-dibromo-3 -nitrilopropionamide (DBNPA) and peroxymonosulfate are synergistic for controlling microorganisms in anaerobic environments, especially sulfide-producing microorganisms.

[0011] In one aspect of the present disclosure, a method of controlling microorganisms on a surface or in a water-containing system under anaerobic conditions comprises treating the surface or the watercontaining system with a synergistic combination of DBNPA and peroxymonosulfate. Docket No.: P003 OOO86-WO-PCT

[0012] In another aspect, disclosed herein is a composition for controlling microorganisms under anaerobic conditions, the composition comprising 2,2-dibromo-3-nitrilopropionamide (DBNPA) and peroxymonosulfate, a peroxymonosulfate source or a combination thereof.

[0013] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention and are intended to provide an ovendew or framework for understanding the nature and character of the invention as it is claimed.

[0014] DETAILED DESCRIPTION OF THE INVENTION

[0015] As used herein, the term “synergistic” and the like mean that the desired antimicrobial effect of the relevant combination against one or more microorganisms 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 =Ca / CA +Cb / CB, where CA is the concentration (ppm) needed of substance A alone to produce the endpoint, CB is the concentration (ppm) needed of substance B alone to produce the endpoint, Cais the concentration (ppm) of substance A needed when it is used in combination with substance B to produce the endpoint, and Cb is the concentration (ppm) of substance B needed when it is used in combination with substance A to produce die endpoint. As in the Examples of the present disclosure, the endpoint may be die minimum concentration required to achieve a certain level of viable bacterial reduction (e.g., at least 99.9% viable 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.

[0016] As used herein, the term “anaerobic microorganisms” refers to microorganisms in anaerobic environments that can grow under conditions with little or no oxy gen due to their ability to metabolize nutrients and carry out biological processes in the absence of oxygen. Strictly anaerobic microorganisms and facultatively anaerobic microorganisms are included within the scope of “anaerobic microorganisms.”

[0017] 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 pipelines or in the bottoms of vessels or equipment (e.g., storage or holding tank bottoms), etc.

[0018] As used herein, “control” or “controlling” refers to killing or reducing the concentration of or inhibiting the growth of microorganisms. Docket No.: P003 OOO86-WO-PCT

[0019] As used herein, the term “effective amount” and the like refer to an amount to provide a desired effect to control microorganisms.

[0020] The methods and compositions of the present disclosure are useful for controlling microorganisms on surfaces and in water-containing systems under anaerobic conditions. The methods of the present disclosure comprise treating the surface or water-containing system with a synergistic combination of DBNPA and peroxymonosulfate. It shall be understood that the present description of treating a surface or water-containing system does not correlate to mutually exclusive embodiments, as it shall be readily recognized that surface contamination is also highly relevant to water-containing systems. 2,2- dibromo-3-nitrilopropionamidc, commonly referred to as DBNPA, is a known biocide used in a variety of industries and is obtainable commercially or can be synthesized by well known techniques. Peroxymonosulfate is a known oxidizing anion (SOs peroxymonosulfate group), commonly referred to and existing in its protonated anionic form (HSOs ).

[0021] The methods and compositions of the present disclosure are not limited to a specific source of the peroxymonosulfate and those skilled in the art will appreciate a wide variety of suitable sources. For example, a suitable peroxymonosulfate source may be a peroxymonosulfate salt. Examples of such salts include those where the cations are chosen from alkali metals, alkaline earth metals, ammonium, primary ammonium, secondary' ammonium, tertiary' ammonium and quaternary' ammonium, such as tctraalkylammonium (c.g., tctra(Ci-C6)alkylarnmonium, such as tctrabutylammonium). Another suitable source of peroxymonosulfate may be a precursor from which peroxymonosulfate can be derived or formed in situ, such as peroxydisulfate or other precursors capable of generating peroxy monosulfate under targeted or relevant conditions.

[0022] In preferred embodiments of the presently disclosed methods and compositions, a source of peroxymonosulfate is a peroxymonosulfate salt chosen from alkali metal peroxymonosulfates and alkaline earth metal peroxymonosulfates. The alkali metal or alkaline earth metal peroxymonosulfate of the present disclosure is chemically representable as MaHb(SOs)c where M is an alkali metal in Group la of the Periodic Tabic or an alkaline earth metal in Group lb of the Periodic Tabic 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 Hb term of MaHb(SO5)c.

[0023] The alkali metal peroxymonosulfates include alkali metal 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 peroxymonosulfate (KHSOs), dipotassium peroxymonosulfate (K2SO5), sodium peroxymonosulfate (NaHSOs), disodium peroxymonosulfate (NazSOs), lithium peroxymonosulfate (LiHSOs), and dilithium peroxy monosulfate (LizSOj). Preferred Docket No.: P003 OOO86-WO-PCT 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 (MgSOs), magnesium dihydrogen diperoxymonosulfate (Mgl FtSO^). calcium peroxymonosulfate (CaSOs), and calcium dihydrogen diperoxymonosulfate (CaFF SOs^).

[0024] Preferably, a suitable peroxymonosulfate source is an alkali metal peroxymonosulfate, more preferably, potassium peroxymonosulfate (KHSOs). In preferred embodiments, the potassium peroxymonosulfate is provided as a component of a multiple salt (i.e., the multiple salt comprises potassium peroxymonosulfate). That is, in such embodiments, the method of the present disclosure includes treating the water-containing sy stem with a multiple salt, wherein the multiple salt provides the potassium peroxymonosulfate (KHSO5). Preferably, the multiple salt is a potassium monopersulfate which is characterized by a hydrogen-bonded structure of potassium peroxymonosulfate (KHSO5), potassium hydrogen sulfate (KHSO4) and potassium sulfate (K2SO4). commonly referred to as a triple salt and can be represented by the general formula (KHSO5)x(KHSO4)y(K2SO4)zfor which tire sum of mole fractions x, y, and z equals 1. The active oxygen component of the potassium monopersulfate triple salt is potassium 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.

[0025] In a particular example, the potassium monopersulfate triple salt used in the presently disclosed methods and compositions 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 oxy gen 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.

[0026] 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%. Docket No.: P003 OOO86-WO-PCT

[0027] The source of peroxymonosulfate, such as a peroxymonosulfate salt or multiple salt containing the same, e.g., a potassium monopersulfate triple salt, may be applied in a solid (e.g., crystalline) form or in a formulated solid form into a fluid or liquid system or may be applied in a liquid form, such as a liquid solution (e.g., an aqueous solution).

[0028] Peroxymonosulfate salts, such as alkali metal or alkaline earth metal peroxy monosulfates, including multiple salts thereof, e.g., 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®.

[0029] The DBNPA in accordance with the present disclosure may be applied in a solid (e.g., crystalline) form or in a formulated solid form into a fluid or liquid system or may be applied in a liquid form, such as a liquid solution.

[0030] The anaerobic microorganisms to be controlled in accordance with the presently disclosed methods are preferably sulfide-producing microorganisms, particularly microorganisms that are capable of generating hydrogen sulfide (H2S). The anaerobic microorganisms typically comprise anaerobic bacteria, such as anaerobic bacteria of the Deltaproteobacteria class. The methods of the present disclosure are especially relevant for controlling certain sulfide-producing microorganisms known as sulfate reducing bacteria (SRB). Examples of genera of such SRB include Desulfovibrio, Desulfocarbo, Desulfobacterium , Desulfobulbus, Desulfoarculus. Desulfobacter, De sulfococcus. Desulfotomaculum, Desulfosporomusa, Desulfosporosinus, De sulfob culum. Desulfocurvibacter. Desulfocurvus, Desulfohalovibrio, Desulfolutivibrio, Desulfohalobium, Desulfonatronospira, Desulfonatronovibrio, Desulfothermus, Desulfonauticus, Desulfovermiculus, Desulfohalophilus, Desulfatibacillum, Desulfomonas, Thermodesulfovibrio, among others. Often, the SRB is of the genus Desulfovibrio, such as Desulfovibrio alaskensis, Desulfovibrio vulgaris, Desulfovibrio longus, De sulfovibrio desulfuricans, Desulfovibrio gabonensis, and other species of the Desulfovibrio genus. The anaerobic microorganisms may include methanogenic archaea, sulfate-reducing archaea, thiosulfate-reducing bacteria and other sulfide-producing anaerobic microorganisms. In general, the anaerobic microorganisms targeted for control by the presently disclosed methods are preferably strict anaerobes, which can grow and carry out metabolic processes in only anaerobic environments.

[0031] The presently disclosed methods and compositions are useful for controlling microorganisms in anaerobic environments in a wide variety of water-containing systems. For example, the anaerobic environment may be in a water-containing system that comprises at least one of injection water, formation water, produced water, flowback water, wastewater, cooling water, source water, a drilling mud, a completion or workover fluid, a hy drotest fluid, a stimulation fluid, a packer fluid, or a fracturing fluid. Docket No.: P003 OOO86-WO-PCT

[0032] In many embodiments, the surface or water-containing system is an underground water-containing system, a closed surface or closed water-containing system, or a lower or bottom part of an open watercontaining system.

[0033] The water-containing system to be treated may be or be part of an oil or gas production system.

[0034] The water-containing system to be treated may be relevant to 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 water-containing 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 or comprise a wellbore (e.g.. a near wellbore area), 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, wastewater, 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.

[0035] Treating a surface or water-containing system under anaerobic conditions in accordance with the present disclosure includes contacting the surface or the water-containing system with DBNPA and peroxymonosulfate, such as in the ratios and amounts as described herein. Further in accordance with tire present disclosure, treating a water-containing system comprises adding or delivering DBNPA and peroxymonosulfate, a source of peroxymonosulfate, such as described herein, or a combination thereof to the water containing system, such as by adding or delivering the materials to a fluid which contacts or flows or is stored within a wellbore, downhole formation, reservoir or well or infrastructure or equipment. For example, the fluid to which the materials may be added or delivered 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 formation, 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, tanks (such as holding tanks, mixing tanks, etc.), flow lines, injection lines, production lines, cooling towers, filtration equipment (e.g., screens or filters, such as membranes), separators, deaeration towers, pumps, Docket No.: P003 OOO86-WO-PCT heat exchangers, etc. The infrastructure or equipment may, for example, transport the fluid from one point to another (such as oil and / or gas pipelines, cooling tower pipelines, fdtration pipelines, water treatment pipelines, etc.).

[0036] 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 DBNPA and peroxymonosulfate, a source of peroxymonosulfate, such as described herein, or a combination thereof may be added or delivered may include gas hydrocarbons, liquid hydrocarbons or a combination thereof. The fluid to which the materials 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.

[0037] 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.

[0038] The ratio by weight of peroxymonosulfate to DBNPA in the methods of the present disclosure preferably ranges from about 40: 1, from about 30: 1, or from about 20: 1 to about 1 : 10 or to about 1 :7, more preferably from about 18.4: 1 to about 1:7. Preferably, the methods and compositions of the present disclosure utilize a combination of DBNPA and peroxymonosulfate, such as peroxymonosulfate derived from a peroxymonosulfate salt, e.g.. an alkali metal peroxy monosulfate (such as KHSOs) or a multiple salt containing the same, having a synergy index (SI) of less than or equal to 0.8, more preferably less than or equal to 0.7, even more preferably less than or equal to 0.6, against at least Desiilfovibrio alaskensis.

[0039] Preferably, in embodiments utilizing a peroxymonosulfate salt, such as an alkali metal peroxymonosulfate (e.g., potassium peroxymonosulfate (KHSOs)). the surface or water-containing system is treated with a weight ratio of the peroxymonosulfate salt to DBNPA of from about 50: 1 or from about 25: 1 to about 1 :8 or to about 1 :6. more preferably from about 24.8: 1 to about 1 :5.2.

[0040] Preferably, in embodiments utilizing a potassium monopersulfate triple salt (such as described herein), the surface or water-containing system is treated with a weight ratio of the potassium monopersulfate triple salt to DBNPA from about 100: 1, from about 75: 1 or from about 50: 1 to about 1 :4 or to about 1:3. more preferably from about 50: 1 to about 1:2.6.

[0041] The present application is not limited to any specific manner or technique for contacting a surface or water-containing system in an anaerobic environment with DBNPA and peroxy monosulfate. In general, the water-containing sy stem is treated such that DBNPA and peroxy monosulfate are contacted with (for example, are or become mixed with or dissolved within) a composition, formulation, fluid or other medium or media that constitutes or is an element of the water-containing system or otherwise are contacted with (for example, are or become mixed with or dissolved within) a fluid for providing Docket No.: P003 OOO86-WO-PCT treatment at the site of interest. For example, the DBNPA and peroxymonosulfate, a source of peroxymonosulfate, such as described herein, or a combination thereof may be added or delivered in respective amounts at the desired ratio to a fluid that contacts or flows or is stored within a wellbore, downhole formation, reservoir or well or infrastructure or equipment, examples of which are described herein. The water-containing system can be treated with the materials at substantially the same tune. 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 concurrently in parallel or as a mixture to the targeted composition, formulation, fluid or other medium or media, e.g.. to a fluid which contacts or flows or is stored within a wellbore, downhole formation, reservoir or well or infrastructure or equipment. Or the water-containing system can be treated with the materials at substantially the same time by adding or delivering the materials 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 materials are added or delivered to the water-containing system at different times (i.e.. with a delay in betw een 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 materials 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 materials in a single dose (or “slug”) or may be added in multiple slugs. The materials may alternatively be continuously added to the water-containing system in order to maintain a desired concentration and ratio of components.

[0042] The exact manner of contacting with or adding or delivering the DBNPA and peroxymonosulfate, a source of peroxymonosulfate, or a combination thereof will depend on various factors, such as on the form or formulation of the materials and the particular surface or water-containing system to be treated. For example, in industrial operations or processing, the materials can be added at a point in a flow line upstream from the point at which controlling microorganisms 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 materials may be added to the water-containing system using mechanical equipment such as chemical injection pumps, piping tecs, injection fittings, quills, and the like. The materials may be added or delivered using an umbilical line or using a capillary injection system.

[0043] The surface or water-containing system can be treated with the DBNPA and peroxymonosulfate to achieve a desired effective amount or concentration on the surface or in the water-containing system, Docket No.: P003 OOO86-WO-PCT 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 DBNPA and peroxymonosulfate necessary to provide the desired antimicrobial effect. In general, the combined concentration of the DBNPA and peroxy monosulfate for treating the surface or water-containing system (such as in a fluid which contacts the surface or contacts or flows or is stored within a wellbore, downhole fonnation, reservoir or well or infrastructure or equipment, such as described herein) may be in the range of from about 5 ppm or from about 40 ppm to about 25000 ppm, such as from about 5 ppm, from about 40 ppm or from about 80 ppm to about 8000 ppm or from about 5 ppm. from about 40 ppm, or from about 80 ppm to about 800 ppm.

[0044] Preferably, in embodiments utilizing a pcro.xymonosulfatc salt, such as an alkali metal peroxymonosulfate (e.g., potassium peroxymonosulfate (KHSOs)), the combmed concentration of the DBNPA and peroxy monosulfate salt for treating the surface or water-containing system (such as in a fluid which contacts the surface or 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 30000 ppm, such as from about 10 ppm, from about 50 ppm or from about 100 ppm to about 10000 ppm or from about 10 ppm. from about 50 ppm, or from about 100 ppm to about 1000 ppm. Preferably, in embodiments utilizing a potassium monopersulfate triple salt, such as described herein, the combined concentration of the DBNPA and a potassium monopersulfate triple salt for treating the surface or water-containing system (such as in a fluid which contacts the surface or 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 60000 ppm, such as from about 20 ppm, from about 100 ppm or from about 200 ppm to about 20000 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.

[0045] The surface or water-containing system may contain or be treated with other agents in addition to the DBNPA and peroxymonosulfate as relevant to the particular industry and application. Examples, particularly for industrial systems, include but are not limited to surfactants, ionic / nonionic polymers, scale inhibitors, corrosion inhibitors, oxygen scavengers, additional biocides and combinations thereof.

[0046] Another aspect of the present disclosure is a composition for controlling microorganisms in an anaerobic environment. The composition comprises a synergistic combination of DBNPA and peroxymonosulfate, a peroxymonosulfate source, such as described herein, or a combination thereof. The ratio by weight of peroxymonosulfate to DBNPA preferably ranges from about 40: 1, from about 30: 1, or from about 20: 1 to about 1 : 10 or to about 1:7, more preferably from about 18.4: 1 to about 1:7. Preferably, the combination has a synergy index (SI) of less than or equal to 0.8, more preferably less Docket No.: P003 OOO86-WO-PCT than or equal to 0.7, even more preferably less than or equal to 0.6, against at least Desulfovibrio alaskensis.

[0047] Preferably, in embodiments utilizing a peroxymonosulfate salt, such as an alkali metal peroxymonosulfate (e.g., potassium peroxymonosulfate (KHSOs)), the ratio by weight of the peroxymonosulfate salt to DBNPA in the composition may be, for example, from about 50:1 or from about 25:1 to about 1:8 or to about 1:6, more preferably from about 24.8:1 to about 1:5.2.

[0048] Preferably, in embodiments utilizing a potassium monopersulfate triple salt (such as described herein), the weight ratio of the potassium monopersulfate triple salt to DBNPA is from about 100: 1. from about 75:1 or from about 50: 1 to about 1 :4 or to about 1 :3, more preferably from about 50:1 to about 1 :2.6.

[0049] The composition can have a wide variety of overall concentrations of DBNPA and peroxymonosulfate, a source of peroxymonosulfate, or a combination thereof. For example, the total concentration of DBNPA and peroxymonosulfate, a source of peroxymonosulfate, or a combination thereof in the composition may be in the range of from about 0.1 wt% to about 99 wt% of the composition, such as from about 5 wt% to about 80 wt% or from about 15 wt% to about 50 wt%. When applying or dosing the composition, the user can dilute concentrated formulations to more appropriate end-use concentrations for a particular application.

[0050] In many embodiments, the composition further comprises one or more solvents. For example, the total solvent concentration may be in the range of from about 1 wt% to about 99 wt% of the composition, such as from about 20 wt% to about 95 wt% or from about 50 wt% to about 85 wt%. Examples of solvents include but are not limited to water, lower alcohols, glycols, glycol ethers and esters, dimethylfonnamide. and combinations thereof, e.g.. water may be combined with one or more cosolvents, such as from those described above.

[0051] The composition may comprise additional ingredients as suitable for the particular application. Examples of other ingredients include but are not limited to surfactants, ionic / nonionic polymers, scale inhibitors, corrosion inhibitors, oxygen scavengers, additional biocides and combinations thereof.

[0052] 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.

[0053] 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’. Docket No.: P003 OOO86-WO-PCT

[0054] Similarly, the term “consisting essentially of’ is intended to include embodiments encompassed by the term “consisting of’.

[0055] As used herein, the term “about” modifying the quantity of an ingredient or reactant employed refers to variation in the numerical quantify 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.

[0056] 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.

[0057] 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.

[0058] EXAMPLES

[0059] In the following examples, the Sy nergy Index (SI) was determined according to SI = Ca / CA + Cb / CB, where

[0060] Ca: Concentration of substance A required to achieve a >99.9% viable bacterial reduction when used in combination,

[0061] CA: Concentration of substance A required to achieve a >99.9% viable bacterial reduction when used alone.

[0062] Cb: Concentration of substance B required to achieve a >99.9% viable bacterial reduction when used in combination,

[0063] CB: Concentration of substance B required to achieve a >99.9% viable bacterial reduction when used alone.

[0064] 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.

[0065] Synergistic control of anaerobic bacteria (in particular, sulfate reducing bacteria).

[0066] Potassium peroxymonosulfate (KHSOs) — provided in the form of a potassium monopersulfate triple salt (available under the brand name OXONE® and commonly represented by the formula Docket No.: P003 OOO86-WO-PCT

[0067] 2KHSO5.KHSO4.K2SO4) — DBNPA, and combinations of DBNPA and the potassium monopersulfate triple salt at different concentrations were prepared in deoxygenated deionized water (deionized water deoxygenated in an anaerobic chamber). The solutions were inoculated with a suspension of Desulfovibrio alaskensis ATCC 14563 to a final 107-8CFU / mL D. alaskensis concentration. After the mixtures were incubated at 30°C for 24 hours, the biocidal efficacy was determined by minimum tested biocide concentrations for 99.9% viable cell reduction in the mixtures. Tables 1, 2 and 3 summarize the efficacy of each treatment and the Synergy Index of each combination on a basis of peroxymonosulfate concentration, potassium peroxymonosulfate concentration, and potassium monopersulfate triple salt concentration, respectively. As shown in the Tables, peroxy monosulfate synergistically enhanced the biocidal efficacy of DBNPA against D. alaskensis.

[0068] Table 1.

[0069] Table 2. Docket No.: P003 OOO86-WO-PCT

[0070] Table 3.

Claims

Docket No.: P003 OOO86-WO-PCTWhat is claimed is:

1. A method of controlling sulfide-producing microorganisms on a surface or in a watercontaining system under anaerobic conditions, comprising treating the surface or the water-containing system with a synergistic combination of 2,2-dibromo-3-nitrilopropionamidc (DBNPA) and peroxymonosulfate at a weight ratio of peroxymonosulfate to DBNPA of from about 20: 1 to about 1:10, preferably from about 18.4:1 to about 1:7.

2. The method of claim 1, wherein the peroxymonosulfate is derived from an alkali metal peroxymonosulfate.

3. The method of claim 1, wherein the alkali metal peroxymonosulfate is potassium peroxymonosulfate (KHSOs).

4. The method of any preceding claim, wherein the method comprises treating the watercontaining system with the synergistic combination, and 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 with the synergistic combination comprises adding or delivering the DBNPA and peroxymonosulfate, a source of peroxymonosulfate, or a combination thereof 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 claim 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, wastewater, cooling water or source water.

8. The method of any one of claims 3-6, wherein the infrastructure or equipment comprises a filter, pipeline, storage vessel, tank, tubing, flow line, injection line, production line, wellhead, separator, pump, heat exchanger, or deaeration tower.

9. The method of any preceding claim, wherein the sulfide-producing microorganisms are sulfate reducing bacteria.

10. The method of claim 9, wherein the sulfate reducing bacteria comprise anaerobic bacteria of the Desulfovibrio genus, preferably wherein the sulfate reducing bacteria comprise Desulfovibrio alaskensis.

11. The method of any preceding claim, wherein the DBNPA and peroxymonosulfate have a synergy index (SI) of less than or equal to 0.8, preferably less than or equal to 0.6, against at least Desulfovibrio alaskensis.Docket No.: P003 OOO86-WO-PCT12. The method of any preceding claim, wherein the peroxymonosulfate is derived from potassium peroxymonosulfate (KHSOs) provided by a potassium monopersulfate triple salt, 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 (KHSOs)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 5-7, wherein the DBNPA and peroxymonosulfate, a source of peroxymonosulfate, or a combination thereof are provided to the water-containing system at substantially the same time.

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