College Station, TX, United States
College Station, TX, United States
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Fichter J.,EnCana Corporation | Janes C.,Hopes Creek | Summer E.J.,Hopes Creek | Mills A.,EnCana Corporation | Hamblen G.,Hopes Creek
NACE - International Corrosion Conference Series | Year: 2017

An oil shale field was found to exhibit classic signs of a heavy microbial burden, including incidences of hydrogen sulfide production, downhole and surface microbially influenced corrosion, downhole pump and surface equipment fouling and fracturing fluid and drilling mud degradation. Over 140 samples, including formation core material, drilling muds, fracturing fluid source waters, production well samples, samples collected from failed pipe surfaces and samples from salt water disposal facilities, were collected in a comprehensive survey. Microbial activity was measured in parallel using four different bacterial quantification methods: 1) traditional MPN culture-based assay for SRB, APB, GHB (aka "bug bottles"), 2) direct visualization and counting bacterial cells utilizing live/dead staining coupled to flow cytometry, 3) an ATP-based assay for metabolically active cells, and 4) a hydrolase-based assay for metabolically active cells. Additionally, the microbial populations of some samples were characterized genetically using 16S amplicon metagenomics. Biocide selection tests were performed with frac water sources and a drilling mud sample. Metagenomics analysis of the formation core material indicated that the indigenous microbial populations were predominantly biodegrading and general heterotrophic microorganisms with minimal to no known problem-causing organisms recovered. The survey results suggested that the bacterial activity could be attributed primarily to introduced water sources as opposed to indigenous formation microbes. Data generated by this exhaustive testing and screening were used to influence biocide choice and applications in the field. The impact of biocides on the field microbial characteristics are described and discussed. © 2017 by NACE International.


Wang L.,General Electric | Pierce C.C.,General Electric | Reynolds D.,General Electric | Summer E.,Hopes Creek
NACE - International Corrosion Conference Series | Year: 2017

Effective microbial control in cooling systems is necessary to ensure system cleanliness and avoid fouling that degrades cooling system performance, promotes corrosion and favors growth of pathogens. However, controlling organisms optimally involves an understanding of the identity of the population of microbes in a system due to the varying susceptibilities of organisms to biocides. This is a challenging task with standard culturing techniques which only allow for a small fraction of the total population to be cultured and identified. In this study, 16s rDNA was employed to maximize the population identification of 40 different independent cooling tower samples. Many of the samples included pair planktonic and sessile samples from the same location. The analysis yielded over 282,000 sequences which corresponded to over 1,700 different taxa, demonstrating extensive diversity not only from remote locations but also within locations of close proximity. This shows that a wide variety of biocides are needed to address microbial populations. ©2017 by NACE International.


Summer E.J.,Hopes Creek | Duggleby S.,Hopes Creek | Janes C.,Hopes Creek | Liu M.,Hopes Creek
NACE - International Corrosion Conference Series | Year: 2014

The acquisition of very large data sets on types of bacteria present in any sample is now routine. For the oil and gas industry, these technologies offer unparalleled opportunities to fill large gaps in the basic understanding of the bacteria associated with corrosion, souring, and biofouling. The ultimate goal of these studies is to correlate bacterial identification with changes in oilfield management practices, for example in the timing and chemistry of biocide applications or the choice of infrastructure materials. We have adopted an approach for interpreting this data by first categorizing the microorganisms based on physiological traits associated with corrosion, souring, degradation, and biofouling. These physiological traits include the capacity generate hydrogen sulfide, acid production, iron reduction, nitrate reduction and sulfur oxidation, and the ability to degrade oilfield chemistries. Here, we present a summary of the distribution of these physiological categories among a collection of samples including brines associated with a storage cavern and a corroding pipeline. These results point to the role of non-SRB sulfidogens, notable thiosulfate reducing bacteria, as well as iron reducing bacteria in the corrosion process. © 2014 by NACE International.


Dickinson W.,Circle Technology | Campbell S.,Hopes Creek | Turk V.,Circle Technology
NACE - International Corrosion Conference Series | Year: 2012

Preservation of petroleum quality and control of microbiologically influenced corrosion (MIC) in petroleum storage and transfer facilities are critical issues in the oil and gas industry. To address these issues, a model storage tank / dead-leg system has been developed and used to establish biocide efficacy in controlling microbiological growth and MIC for use in these facilities. The model system employs a glass tank reactor containing a dodecane/aqueous phase solution in combination with a 12-position modified Robbins device (MRD) which serves as the dead-leg. Removable carbon steel coupons in the tank and dead-leg enable determination of sessile bacterial populations. In tests using an oilfield consortia of sulfate-reducing (SRB), acid-producing (APB), and general heterotrophic bacteria (GHB), a proprietary broad-spectrum oilfield biocide was shown to effectively control growth of planktonic and sessile bacteria both in the tank and the dead-leg segment, achieving a 4 to 6 - log reduction in viable bacteria and exhibiting both short-term and sustained microbial control. Corrosion analysis of metal coupons exposed to bacteria in the dead-legs demonstrated a dramatic mitigation of corrosive attack for the biocide-treated coupon compared to an untreated control. ©2012 by NACE International.


Heller R.,Hopes Creek
International Journal of Innovation Science | Year: 2013

Ecosystems supporting innovation are being created in many developing countries. Russia is no exception. An examination of the status of the emerging ecosystem in Russia is presented here with indications of its strengths and weaknesses. Six major categories are studied and rated in a relative system of comparison between Russia and various emerging markets as well as the United States. The rating for each category employs several factors which sum to provide a view of the overall standing of the country in areas of market, capital, people, culture, infrastructure and regulations.


Fichter J.,EnCana Corporation | Summer E.J.,Hopes Creek | Janes C.,Hopes Creek | Hamblin G.,Hopes Creek
NACE - International Corrosion Conference Series | Year: 2015

Monitoring of microbial populations in oil and gas operations is routinely conducted in order to evaluate the need for and performance of biocides. Operators utilize a variety of methods designed to determine if bacteria and archaea capable of causing corrosion, fouling, or souring are present in the systems before, during, and after control methods are applied. Each monitoring method has strengths and limitations, and an understanding of the strengths and limitations is crucial to deciding the best method for any given system. The most obvious considerations are the accuracy of the test, cost, ease of use, and time required to obtain the results. How comparable results are from a given location or time to another time, and the value of the data for making higher-level decisions also should be considered. In this study, we will share the results obtained from analyzing samples collected from various phases of natural gas and oil production operations. These locations include microbial populations collected from a range of operating temperatures, pressures and salinities as well as those treated with different types of biocides. Four methods, culture based enumeration using bug bottles with indicator media for sulfate-reducing bacteria (SRB) and acid-producing bacteria (APB), rapid bacterial cell enumeration based on an adenosine triphosphate (ATP) quantification assay, epifluorescence microscopy, and molecular analysis of the microbial populations by DNA isolation and sequencing of 16S amplicons were directly compared. The results are discussed in terms of agreement between the methods, difficulty of the approaches, and the relative value of each data set for future use. © 2015 by Nace International.


Wrangham J.B.,Baker Hughes Inc. | Summer E.J.,Hopes Creek
NACE - International Corrosion Conference Series | Year: 2013

Obtaining representative and accurate microbiological samples often proves challenging in the oil and gas industry. It is common to sample and test fluids (containing planktonic/free-floating microbes) for the detection and enumeration of problematic species, despite the fact that biofilms or sessile (attached to pipe or vessel wall) microbes are those which cause the majority of problems. This practice occurs because many field scenarios do not allow for sessile sampling. Collecting a representative sample is imperative in any microbial monitoring program, as they estimate the possible risk to the facilities. Misinformation can lead to microbiologically influenced corrosion (MIC) failures or other costly consequences. These planktonic samples are also often used for kill tests, or biocide selection testing, which may not accurately determine the ideal chemistry for the eradication of the sessile bacteria consortia. In this study, metagenomic population analyses of planktonic and sessile samples taken from three geographically distant locations reveals that the planktonic sample population is not representative of the sessile population. In fact, planktonic and sessile samples from the same location may be as different from each other as they are to samples obtained from other locations. Therefore, planktonic sample analyses should not be inferred to accurately or satisfactorily represent the sessile population and associated risk to the facilities. © 2013 by NACE International.


PubMed | National United University, Hopes Creek and Texas A&M University
Type: | Journal: Biotechnology for biofuels | Year: 2015

Contamination of corn mash by lactic acid bacteria (LAB) reduces the efficiency of the ethanol fermentation process. The industry relies heavily on antibiotics for contamination control and there is a need to develop alternative methods. The goals of this study were to determine the diversity and abundance of bacteria contaminating commercial ethanol fermentations, and to evaluate the potential of anti-LAB bacteriophages in controlling production losses.Bacterial populations in 27 corn mash samples collected from nine different commercial plants were determined by pyrosequencing of 16S rRNA amplicons. The results showed that the most abundant bacteria (>50% of total population) in 24 of the 27 samples included LAB genera such as Lactobacillus, Streptococcus, Lactococcus, Weissella, Enterococcus, and Pediococcus. Lactobacillus was identified as the most prevalent genus at all fermentation stages in all plants, accounting for between 2.3 and 93.7% of each population and constituting the major genus (>50%) in nine samples from five plants and the most abundant genus in five other samples. Lactobacillus species, including L. delbrueckii, L. fermentum, L. mucosae, and L. reuteri were the most well-represented species. Two bacteriophages that target L. fermentum strains from ethanol plants, vB_LfeS_EcoSau and vB_LfeM_EcoInf (EcoSau and EcoInf), were isolated and characterized as a siphophage and a myophage, respectively. Analysis of the 31,703bp genome of EcoSau revealed its similarity to the P335-like phage group, and the 106,701bp genome of phage EcoInf was determined to be a novel phage type despite its distant relationship to the SPO1-like phages. Addition of phages EcoSau and EcoInf to L. fermentum-contaminated corn mash fermentation models restored the yields of ethanol and reduced levels of residual glucose, lactic acid, and acetic acid to that comparable to the infection-free control.This study provides detailed insight into the microbiota contaminating commercial ethanol fermentations, and highlights the abundance of LAB, especially L. delbrueckii, L. fermentum, L. mucosae, and L. reuteri, in the process. This study suggests that phages with broad coverage of major LAB species can be applied directly to corn mash for antibiotic-free control of contamination in the ethanol fermentation industry.


PubMed | Hopes Creek and Texas A&M University
Type: | Journal: Scientific reports | Year: 2015

Filamentous bacteria are a normal and necessary component of the activated sludge wastewater treatment process, but the overgrowth of filamentous bacteria results in foaming and bulking associated disruptions. Bacteriophages, or phages, were investigated for their potential to reduce the titer of foaming bacteria in a mixed-microbial activated sludge matrix. Foaming-associated filamentous bacteria were isolated from activated sludge of a commercial wastewater treatment plan and identified as Gordonia species by 16S rDNA sequencing. Four representative phages were isolated that target G. malaquae and two un-named Gordonia species isolates. Electron microscopy revealed the phages to be siphophages with long tails. Three of the phages--GordTnk2, Gmala1, and GordDuk1--had very similar ~76kb genomes, with >93% DNA identity. These genomes shared limited synteny with Rhodococcus equi phage ReqiDocB7 and Gordonia phage GTE7. In contrast, the genome of phage Gsput1 was smaller (43kb) and was not similar enough to any known phage to be placed within an established phage type. Application of these four phages at MOIs of 5-15 significantly reduced Gordonia host levels in a wastewater sludge model by approximately 10-fold as compared to non-phage treated reactors. Phage control was observed for nine days after treatment.


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