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Results
Enhancement of Alkyldimethylbenzylammonium Chloride and Tributyl Tetradecyl Phosphonium Chloride Biocides using D-Amino Acids against a Field Biofilm Consortium
Jia, Ru (Ohio University) | Yang, Dongqing (Ohio University) | Al-Mahamedh, Hussain H. (3Saudi Basic Industries Corporation) | Li, Yingchao (Beijing University of Technology) | Gu, Tingyue (Ohio University)
Abstract Biocorrosion or microbiologically influenced corrosion (MIC) is a major problem in many industries, especially the oil and gas industry. Biofilms are the culprits of MIC. In this work, D-amino acids were used to enhance two biocides, namely alkyldimethylbenzylammonium chloride (ADBAC) and tributyl tetradecyl phosphonium chloride (TTPC), to treat a tough and corrosive field biofilm consortium on C1018 carbon steel coupons. An equi-mass D-amino acid mixture (“D-mix”) of four D-amino acids (Dmethionine, D-tyrosine, D-leucine, and D-tryptophan) at a total concentration of 50 ppm (w/w) was tested. The cocktails of 60 ppm ADBAC + 50 ppm D-mix and 40 ppm TTPC + 50 ppm D-mix both achieved a 3-log reduction of the sessile cell count of sulfate reducing bacteria (SRB) in the 7-day biofilm prevention test compared with a 1-log reduction achieved by 60 ppm ADBAC and 40 ppm TTPC alone separately. In the 3-hour biofilm removal test that started with mature biofilms on C1018 carbon steel coupon surfaces, the cocktails of 150 ppm ADBAC + 50 ppm D-mix and 100 ppm TTPC + 50 ppm D-mix both achieved a 2-log reduction compared with a 1-log reduction achieved by 150 ppm ADBAC and 100 ppm TTPC alone separately. In all the tests, D-mix alone showed no log reduction. Scanning electron microscope images and confocal laser scanning microscope images supported the results. Introduction Biocorrosion, also known as microbiologically influenced corrosion (MIC), is a major problem in various industries, particularly in the oil and gas production industry.In this industry most produced fluids are free of any dissolved oxygen, with some exceptions (e.g., injected waters in some cases). Oxygen is removed using nitrogen sparging and/or oxygen scavengers because it is very corrosive. Even in openair storage tanks, an aerobic biofilm provides a locally anaerobic environment for an anaerobic biofilm to thrive underneath it. The electrons released by the oxidation of Fe must be absorbed by an electron acceptor (oxidant) to maintain electroneutrality. In the absence of oxygen, sulfate, nitrate, proton (at low pH) and other chemical compounds can serve as electron acceptors, leading to anaerobic corrosion. However, the reduction of some of these oxidants requires biocatalysis to proceed with an appreciable speed. Sulfate reducing bacteria (SRB) are capable of catalyzing sulfate reduction in their cytoplasm, while nitrate reducing bacteria (NRB) can catalyze nitrate reduction in NRB cytoplasm. They cause Type I MIC, which requires the transfer of extracellular electrons from iron oxidation to the cytoplasm. Li et al. pointed out that the cross-cell wall electron transfer process is a limiting step in carbon steel corrosion by SRB. It requires an electrogenic biofilm. Planktonic cells do not perform cross-cell wall electron transfer and thus they do not cause Type I MIC. Type II MIC is caused by corrosive metabolites. For example, acid producing bacteria (APB) can secrete organic acids that cause locally low pH underneath their biofilms. Type II MIC’s proton reduction reaction does not require biocatalysis. This is why acid attack can occur abiotically unlike sulfate attack. Because the sessile cell density in a biofilm can be more than 10 times denser than the planktonic cell density in the bulk fluid, the pH underneath the biofilm can be much lower than the bulk-fluid pH, leading to significant acid corrosion. Thus, it is clear that in both types of MIC, biofilms are the culprits.
- North America > United States > Texas (0.72)
- Asia (0.68)
- Materials (1.00)
- Health & Medicine (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Constituents > Treated Chemicals (0.66)
Abstract: Hydraulic fracturing and Enhanced Oil Recovery (EOR) polymer floods present new and technically challenging demands for biocides, with the need to couple high performance with system compatibility to provide flexible and effective treatment programmes. Formulated tetrakis hydroxymethyl phosphonium sulfate (THPS) technologies have been developed that have improved compatibility, at high dose concentrations, with friction reducers and biopolymers used in EOR programmes and fracturing applications. The updated formulations have shown enhanced biocidal efficacy against acid producing bacterial (APB) species. Typical fracturing fluid systems have been investigated and the ability to introduce biocide and oxidising breakers effectively demonstrated. Supplementary mitigation of iron sulfide and organically coated inorganic scale typically rich in iron sulfides, referred to as schmoo has also been investigated using optimised levels of THPS and polymeric additive. Introduction Deployment of tetrakis hydroxymethyl phosphonium sulfate (THPS) in the Oil & Gas industry has advanced over the last 2 decades via a series of formulated products each designed to meet increasingly stringent environmental regulations and challenging application requirements. In simple terms, THPS formulations have advanced from the use of the generic unformulated molecule, to blends containing surfactants, polymeric quaternary ammonium blends and then to a synergistic blend of THPS and sulphonated, anionic polymer for biofilm control. Typical formulation components and anticipated performance improvements are summarised in Table 1. THPS Containing Formulations In recent years, the growing hydraulic fracturing market, particularly in the USA, has provided additional challenges for THPS containing formulations that were not considered relevant for the oilfield ‘production’ applications where THPS and previous formulations have traditionally been used. In particular, the need for improved compatibility with friction reducers and biopolymers used for EOR programmes and as part of slickwater and gel fracturing fluids has become an important consideration. Biocide selection needs to prevent and control bacterial contamination of these fluids thus avoiding biofouling and the associated increased microbially influenced corrosion (MIC). However, the selected biocide must not impact upon the flow characteristics of these fluids.
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Chemical flooding methods (0.91)
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (0.89)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene (0.78)
- (2 more...)
Abstract The use of corrosion sidestream units can enhance understanding of corrosion mechanisms and optimize the chemical injection rates. However, as always, there are pitfalls, challenges and weaknesses related to the test method and the experiences described here may be helpful for future field studies. Usually, it is not possible to mimic the full range of field conditions in the laboratory environment, which can potentially lead to insufficient and misleading information. Field studies may seem as challenging operations, however the resulting data is often significantly more realistic compared to the information obtained in laboratory studies, and often provides quality data for decision support. With emerging technologies, the field studies can be performed with a minimum workload for the operational personnel. The main workload is normally up front of the test, and the duration of the test is normally less important as it has minimal impact on operational routine. This opens a window of opportunity for time and cost effective studies of slow evolving corrosion mechanisms, for example microbiologically influenced corrosion (MIC), and finding suitable mitigation treatments for them. Experience dictates that in many cases, the use of corrosion sidestream units may be equally or more cost effective when matched with laboratory evaluation methods. Introduction During last several decades, the economic consequences of corrosion in various oil and gas (O&G) operations have been well documented. Internal corrosion causes immense damages to low-alloyed steel offshore infrastructures such as pipelines and water injection systems. Thus, the impact of corrosion on the operational capacity and life cycle of various assets and infrastructures in the O&G industry is increasingly coming into focus. Degradation of ferrous alloys is a consequence of chemical, electrochemical and/or mechanical interactions of a specific ferrous alloy with its surrounding environment that results in material loss.3 Wide ranges of mitigation treatments are applied to combat the ongoing corrosion in the production process. Some mitigation options include the use of production chemicals. Depending on the origin of corrosion, different chemicals can be applied: corrosion inhibitors, biocides and H2S scavengers. They can be applied separately or together to achieve a synergetic effect.
- North America > United States (1.00)
- Europe > United Kingdom > North Sea (0.40)
- Europe > Norway > North Sea (0.40)
- (2 more...)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Disposal/Injection (0.55)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (1.00)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery (1.00)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- (2 more...)
A Comprehensive Approach to Diagnosing a Solution for a South Texas Production System with Severe MIC
Tidwell, Timothy J. (NALCO Champion, an Ecolab Company) | De Paula, Renato (NALCO Champion, an Ecolab Company) | Broussard, Zach (NALCO Champion, an Ecolab Company) | Keasler, Victor (NALCO Champion, an Ecolab Company)
Abstract Microbially Influenced Corrosion is primarily caused by sessile microbes found within a biofilm. The ultimate goal of many biocide treatments is the removal of any biofilm within that system. These cells may be killed but remain in place, be removed but not killed, or may be both killed and removed. Many of the factors that determine the fate of sessile cells are poorly understood. For example, deciding to treat a system with a low dose of biocide for a long period of time or to treat with a high dose of biocide for a short period of time may yield drastically different results in terms of reducing the risk of microbially influenced corrosion. In this study, we show a comprehensive approach to growing in vitro biofilms to conduct sessile kill studies for product qualification. Introduction Microbiologically Influenced Corrosion (MIC) is a major cause of corrosion failures in oilfield production and water injection systems. Microbes thrive in the anaerobic conditions encountered in these systems and are supported by nutrients and metabolites found in produced water. Some biocides possess surface active properties which make them more suitable to kill the free floating planktonic bacteria and facilitate penetration and removal of the biofilm from metal surfaces. A biocide’s ability to penetrate and loosen a biofilm is a key factor when selecting the correct chemistry to combat MIC for a particular application. Despite the importance of the characteristics described above, it is still rare for biocide decisions to be based off of credible techniques that accurately measure biocide performance. To gauge efficacy of a biocide in oilfield production systems, it is common practice to conduct a time kill study against planktonic bacteria using culture dependent methods (serial dilution). Kill studies aimed at sessile microbes are performed far less often despite the fact that the most serious issues posed by oilfield microbes are associated with biofilms. Previous research has established that it is substantially easier to kill planktonic microbes than microbes found in a biofilm ¹. For example, Costerton et al. have demonstrated that some species of bacteria are 500 to 5000 times less susceptible to biocide treatment in biofilm form than that same species of bacteria found in planktonic form ².
- Research Report > New Finding (1.00)
- Research Report > Experimental Study (0.95)
- Water & Waste Management > Water Management > Constituents (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Disposal/Injection (0.54)
Abstract Microbiologically influenced corrosion (MIC) is a significant challenge in the oilfield that results in substantial cost for the operator in downtime, pipe and equipment replacement, and safety hazards associated with failures. Although biocide treatments are usually performed to minimize the risk of MIC, this is often challenging to control a microbial population present as a biofilm. To this end, a novel biocide has been developed to provide enhanced microbial kill within a biofilm as well as biomass removal. The novel biocide was evaluated against biofilm populations grown in anaerobic conditions in bioreactors. The results indicated that the new chemistry provided superior results when compared to commonly used and best-in-class products. Enhanced microbial kill and removal of biomass was evidenced by Confocal laser Scanning Microscopy of biofilms grown on the surface of C1018 carbon steel coupons. Further, additional tests demonstrated that the novel product neither negatively impacts the oil and water interface nor causes corrosion in the metallurgy. Introduction Microbiologically-influenced corrosion (MIC) poses a serious concern to production and integrity of pipelines, vessels and tanks and can have a significant impact on the cost of operations in oilfields. As the assets age, the increasing water cuts directly potentiates the risk for MIC, as the microbial load in the system become more prominent. MIC is estimated to account for up to 20% of the costs associated with pipeline integrity, exceeding $2 billion USD per year. Microbes can be introduced in oil/gas production systems from the initial steps of drilling and completion of a well and during shut ins. Microbes can also be introduced during secondary and tertiary oil recovery, when fluids are injected into the formation to maintain reservoir pressure and push hydrocarbons out. Moreover microorganisms can exist endogenously in the petroleum reservoir. The diversity of microorganisms found in oil/gas production systems is extremely broad, with well over 800 documented genus identified to date. These microbes, under certain environmental conditions, are capable of causing significant challenges in oil and gas systems such as microbiologically influenced corrosion (MIC), biotic hydrogen sulfide (H2S) production, and biofouling of membranes, filters, and heat transfer equipment. Microbial risks become significantly more challenging when the microbial community colonizes parts of the system, forming biofilms that can increase the rates of localized corrosion, ultimately leading to leaks and failures.
- Water & Waste Management > Water Management > Constituents > Treated Chemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
The Selection and Performance of Oil and Gas Biocides for Extended Microbial Control
Williams, Terry M. (The Dow Chemical Company) | Mohan, Arvind Murali (The Dow Chemical Company) | Amponsah, Emmanuel Appiah (The Dow Chemical Company) | Moore, Joseph (The Dow Chemical Company) | Schultz, Christine (The Dow Chemical Company) | Massie-Schuh, Ella (The Dow Chemical Company) | Dyer, Diamond (The Dow Chemical Company) | Pham, Phuc (The Dow Chemical Company) | Maun, Philip (The Dow Chemical Company)
Abstract It is well understood that sulfate reducing bacteria (SRB), acid-producing bacteria (APB), and facultative anaerobic bacteria may cause a range of problems in oil and gas applications including the production of hydrogen sulfide (souring), microbially influenced corrosion (MIC), and additive spoilage. These problems may ultimately reduce the quality of the hydrocarbon produced, decrease the durability of structural assets, and accelerate formation damage. Microbial contaminants may originate from poorly treated source waters and process fluids (e.g., drilling fluids) as well as resident organisms existing in the subsurface environment. The antimicrobial performance of oil and gas biocides is dependent on their stability and compatibility with key environmental parameters in applications such as hydraulic fracturing and water flooding. For an extended microbial control program, the biocide must survive and function under varying conditions. The most aggressive conditions involve the downhole environment where temperature and salinity extremes may occur and reactivity with the substrata (rocks, mineral, soil, hydrocarbons) create a complex set of interacting influences. This study investigated the interactions of several oil and gas biocides in the presence of subsurface rock matrices (Berea sandstone). The effect of the rock on biocide adsorption was determined analytically and the resulting impact on residual efficacy was assessed by microbial viability. Certain actives were more adsorptive to solid rock substrata than others. Cationic (surface active) biocides with long-chain hydrophobic moieties were shown to rapidly bind to Berea sandstone rock and be removed from the water phase, resulting in a loss of antimicrobial efficacy. Non-surface active biocide chemistries showed better compatibility and resulting efficacy after contact with subsurface materials (sandstone rock). For the adsorptive biocides, high levels of rock (1:1 rock to water ratio) resulted in complete loss of efficacy. The results of these studies provide insight and guidance into the selection and use of oil and gas biocides for downhole applications, where compatibility with complex environmental parameters is required in order to provide long-term extended microbial control.
- Geology > Mineral (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.72)
- Water & Waste Management > Water Management > Constituents > Treated Chemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
Abstract There are two major groups of biocides used in the oil and gas industry to prevent souring, formation plugging, and microbiologically influenced corrosion: oxidizers and non-oxidizers. Oxidizing biocides include chlorine and bromine based biocides, ozone, and peracetic acid, among others. Non-oxidizing biocides can be further categorized into three sub-groups: membrane active (quaternary ammonium and tetraalkyl phosphonium based), fast reactive (glutaraldehyde, dibromo nitrilopropionamide, and tetrakis(hydroxymethyl) phosphonium sulphate), and slow reactive or preservative-type biocides (dimethyl oxazolidine, tris(hydroxymethyl)nitromethane, and chloroallyl triaza azoniaadamantane chloride). The recent trend toward drilling environments at higher temperature and pressure is placing greater demands on the properties and performance of these biocides. In addition, depending on the type of fracturing fluids being used, there can be large differences in pH, from lower pHs in slickwater fluids to higher pHs in crosslink gel fluids that can place even more demand on biocides. Determining how biocides will behave in these high temperature and broad range pH environments is important to maintaining a clean, high producing well. This paper presents the results of hydrothermal stability and performance testing for the three non-oxidizing biocide groups in varying pH and temperature conditions. Results indicate that membrane active biocides showed the best overall stability, while the fast reactive biocides were the least stable overall. The preservative-type biocides were affected to a greater degree by pH than temperature. The combination of a fast reactive with a membrane active biocide showed moderate stability. In terms of speed of biocidal activity and long-term stability of biocidal activity, either combination biocides or membrane active biocides were the most effective. Introduction Whether being used for conventional or unconventional oil and gas applications, appropriate biocide selection for microbial control is essential for safe and efficient well operation. Biocides help to mitigate souring, formation plugging, microbial influenced corrosion (MIC), and personnel health and safety issues, among other potential microbiological related problems. Common biocides used for the oil and gas industry can be divided into two main groups of either oxidizing or non-oxidizing biocides. As the name suggests, oxidizing biocides kill microbes through the chemical process of oxidation, where the electrophilic nature of the biocide react with and destabilize the microbial cell causing irreversible damage and cell death.7 Non-oxidizing biocides work through multiple mechanisms and can be further categorized into fast reactive, membrane active, or slow reactive/preservative type biocides. Fast reactive biocides disrupt microbial cell function by interfering with mechanisms such as microbial metabolism, replication, and other macromolecule function rendering the cell incapable of functioning properly. Membrane active biocides interact with the microbial cell phospholipids, disrupting membrane integrity inducing cellular leakage. Slow reactive or preservative type biocides react similarly to fast reactive biocides but need to be hydrolyzed over time to release the reactive compound that will interfere with microbial cell function. All of these mechanisms lead to subsequent microbial cell death.
- Reservoir Description and Dynamics > Improved and Enhanced Recovery (1.00)
- Well Completion > Hydraulic Fracturing (0.90)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers > Materials and corrosion (0.87)
- Well Completion > Well Integrity > Subsurface corrosion (tubing, casing, completion equipment, conductor) (0.69)