Bacteria control has recently become an important topic for discussion among the oil and gas industry, although it can still be misunderstood. A bacteria problem can oftentimes be subtle and difficult to detect. Bacteria detection in the field is difficult because many tests take a long period of time or are simply not accurate. New regulations on flowback and water production have led to the investigation of ways to reduce the amount of residual chemicals in flowbacks. Environmental concerns associated with chemical disinfection have led to the move from traditional chemical disinfection to mechanical procedures (Cho et al. 2002). Water that is used to make fracturing fluids usually requires treatment to reduce aerobic acid-producing bacteria and, more importantly, to eliminate anaerobic sulfate-reducing bacteria that can cause a well to go sour. Typically, this treatment is performed using chemical biocides. Using ultraviolet (UV) light to disinfect water on-the-fly for stimulation treatments will greatly reduce the amount of chemical biocides that are necessary. The effectiveness of UV light in disinfecting water for a fracturing treatment was tested in both a controlled laboratory environment and also on a fracturing location. The equipment used to generate sufficient UV light to disinfect the large volumes of water needed for fracturing was mounted on a trailer for road mobility.

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This paper describes a proven method to control bacteria growth in pipeline and process service fluids using irradiation technology. Service fluids are exposed to an irradiation source that disinfects the fluids and eliminates the need for biocide chemistry. The disinfection process can be used as a standalone process or in conjunction with traditional chemical treatments for many oilfield service applications.The commissioning process for pipelines typically requires hydrostatic-pressure testing. The test fluid is usually treated for potential bacteria accumulation. Using the nonchemical process of irradiation to disinfect the test fluid eliminates the need for hundreds of gallons of bactericide. The service greatly reduces employee exposure to hazard-rated biocides and associated healthand safety-related issues, significantly improving overall environmental aspects of the operation.Bacteria play an important, although usually detrimental, role in the production and transportation of hydrocarbons. The slimeforming version of bacteria can corrode surface piping and storage facilities. In addition, bacteria have been known to restrict reservoir porosity with "bio-plugging" or "bio-fouling." One anaerobic form of bacteria is sulfate reducing bacteria (SRB), which reduces the sulfate ion to sulfide. This can lead to the corrosion of flow-wetted metal components and to the formation of hydrogen sulfide (H 2 S) gas, which is extremely hazardous to humans and other animals. Fluids containing H 2 S can be damaging to production facilities not specifically designed to be H 2 S resistant.The nonchemical alternative to biocide has cost and environmental advantages over traditional chemical treatments.