Raymond J.,Dow Microbial Control |
Parnell E.,Baker Hughes Inc. |
Fichter J.,Encana Oil and Gas United States Inc.
NACE - International Corrosion Conference Series | Year: 2014
Conventional antimicrobial treatments for hydraulic fracturing fluids, flow-back water, and produced water include chemistries such as glutaraldehyde, tetrakis-(hydroxymethyl)-phosphonium sulfate (THPS), and quaternary ammonium compounds (quats). While the rapid microbial kill efficacy of these biocides in top-side water sources are effectively demonstrated by traditional microbial enumeration methodologies, such as "bug-bottles", the long-term potential for protection of the oil and gas reservoirs from microbial-induced damage has received limited attention. A stringent two-stage laboratory method has been developed to assess rapid and long-term biocide efficacy, ranging from the mild, top-side conditions of water sources in drilling and fracturing operations to the harsh conditions of downhole environments. Specifically, water sources used in stimulation and fracturing operations were treated with various concentrations of biocide combinations and incubated at elevated temperatures during the course of the laboratory experimental procedure. At predetermined time points during the two-month test, the heat-aged samples were challenged with oil and gas field microbial contaminants (acidproducing and sulfate-reducing bacteria) to evaluate extended biocide performance in water chemistries and temperatures that mimicked downhole environments. This paper discusses a summary of effective biocide treatments for the holistic protection of hydraulic fracturing operations from microbial contamination. © 2014 by NACE International.
Browne B.A.,Dow Microbial Control
12th International Conference on Stability, Handling and Use of Liquid Fuels 2011 | Year: 2011
Many species of bacteria, mold, and yeast have the ability to utilize the hydrocarbons that make up fuel as their sole carbon source for growth. Bacterial and fungal contamination negatively impacts fuel performance properties such as engine efficiency and stability, and may increase the frequency of equipment malfunction, engine failures, aircraft gauge malfunction, and impaired water removal from storage tanks. Optimized biocide usage is critical to the fuel industry to maintain the integrity of fuels at all points during storage, distribution, and usage to prevent unnecessary disposal of valuable fuel products and equipment. Herein, microbial challenge test data are presented to demonstrate effective usage of several biocidal chemistries to protect against fuel spoilage by the industrially relevant organisms Pseudomonas aeruginosa (bacterium), Hormoconis resinae (filamentous fungus), and Yarrowia tropicalis (yeast). Effective dosing strategies (e.g., maintenance versus shock treatments) will be discussed along with steps for prevention of fuel spoilage. A holistic strategy on sustainable practices will be presented which includes comparisons of environmental and toxicological data for a variety of fuel preservation products.
N'Guessan S.,FTS International Inc. |
Raymond J.,Dow Microbial Control |
Navarrete R.,FTS International Inc.
Proceedings - SPE International Symposium on Oilfield Chemistry | Year: 2015
Combining a biocide's effectiveness to reduce bacterial growth as well as ensuring its compatibility with fracturing fluids is a common challenge faced in oilfield applications. This paper describes a series of biocides and combinations of biocides with an improved environmental profile, which protect the formation and proppant pack for extended periods of time. Different biocides were selected based on their environmental and toxicological profile, and their ability to reduce bacterial growth for up to 7 weeks. Two types of biocides were evaluated: (1) rapid-kill biocides under conditions mimicking surface conditions and (2) preservative biocides under conditions mimicking long-term reservoir conditions. Combinations of both biocide types were also evaluated. Two types of fracturing fluids were used including a fully formulated slickwater system and a fully formulated linear guar gel. The fracturing fluids containing the biocides were heat-aged for 50 days at 167°F. Periodically, samples were extracted and challenged with stock cultures of SRB and APB for bacterial kill studies. The results demonstrated that preservative biocide chemistries can be effective in the protection of the fracture for extended periods of time. Also, optimum combinations of rapid kill biocides and long term preservatives were observed that can be effective in the short and long term. In some cases, enhanced antimicrobial effects were observed between the two biocide types that augmented the long term effect of the preservatives. The results of this study demonstrate a systematic process for optimization of biocide treatments capable of protecting the formation and fracture long after the fracturing process has ceased. The benefit for the well is compounded in that polysaccharide gelling agents and high molecular weight friction reduction agents, present in many fracturing fluid formulations, act as food for bacteria in the fracture. If prolonged bacterial growth is not controlled in the fracture following treatment, then the long term viability of the well is put at risk. Copyright 2015, Society of Petroleum Engineers.
Majamaa K.,Dow Water and Process Solutions |
Johnson J.E.,Dow Water and Process Solutions |
Bertheas U.,Dow Microbial Control
Desalination and Water Treatment | Year: 2012
Exposure to water containing micro-organisms causes biofouling on reverse osmosis (RO) membranes as they adhere, multiply and produce extracellular polymeric substances (ESP) which form biofilm on the surface of the membrane. As micro-organisms are present in virtually every water system, biofouling is one the most commonly encountered fouling types in large and small scale RO installations treating surface, wasteor seawater. Biofouling control is significantly improved when multiple methods are combined in an integrated approach and prevention methods employed in the RO stage itself are applied. In this study the impact of new membrane chemistry, feed spacer thickness and the use of non-oxidative biocide upon to the rate of biofouling in RO systems was investigated using a pilot-scale experiment involving small membrane elements subject to a high-fouling feed and autopsy-based analysis of membrane foulant loading and composition. The results were as follows: (1) The benefit of using the newest development in the family of fouling resistant (FR) membranes, DOW FILMTEC™ BW30XFR, was validated with side-by-side operation where lower rate of flux loss was observed when compared to the current industry standard membrane, BW30. (2) Thicker feed spacers provided reduced pressure drop and reduced rate of pressure drop increase during episodes of fouling. Overall organic foulant loading and bacterial counts were found to be reduced on membrane used in combination with thicker spacers. (3) The clear benefit of DBNPA dosing was observed with both shock and continuous dosing regimes. The benefit was most visible in the evolution of Δp as the treated elements operated at significantly lower Δp. Autopsy based results verified significantly lower organic fouling loading on the biocide treated element. These results point to the value of the studied factors-membrane chemistry, feed spacer configuration, and biocide dosing-for use with high-fouling feeds. The suggested route is to combine the components for use as an integrated strategy to solve biofouling. Combining a FR membrane with a thick feed spacer is preferred whenever a high potential for biofouling is seen. The use of targeted biocides in the pretreatment section will further result in improved fouling prevention and ensure long-term trouble free operation, maximizing the membrane lifetime and minimizing the operational expenses of the treatment system. © 2012 Desalination Publications. All rights reserved.
Yvon E.,Dow Microbial Control
European Coatings Journal | Year: 2014
The article examines how technology enhances protection and meets regulatory and performance requirements. In high summer in Central Europe, one cubic meter of air often contains more than 20,000 fungal spores and algae. By comparison, during the same time period, the pollen content of the air is significantly lower with a maximum of 2,000 particles. If one of these spores lands on a surface with suitable growth conditions, germination will occur and the substrate will become colonized. Subsequently more spores will be produced, and growth will occur anywhere that adequate living conditions exist for this particular species, with the entire surface becoming overgrown in a very short period of time. Whilst the initial pH of cementitious substrates or those treated with silicate-based coatings may be too high to prevent initial colonization, weathering and erosion of the coating over time will allow fungi and algae to grow. Film breakdown can also be caused by the corrosive metabolites produced by microbial growth, mainly acids.