Enhanced kill of microorganisms
AssigneeConocoPhillips Company
InventorGary JENNEMAN
Life of this patent
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Abstract
A process is provided for the time dependent reduction and kill of cellular bacteria in a fluid by sequential exposure to nitrites and a low concentration of biocide. Oilfield water containing sulfate-reducing bacteria can be supplied with a timed sequential exposure of nitrite and biocide. The timed sequential addition of the biocide following exposure to the nitrite provides enhanced kill of the sulfate-reducing bacteria at concentrations of biocide that are lower than would be possible using simultaneous addition of these materials.
Claims29
1) A method of killing microbes in an aqueous medium, the method comprising:
- a) contacting microbes present in an aqueous medium with a first concentration of an ATP-reducing agent;
- b) waiting a first period of time to significantly stress said microbes by reducing ATP levels in said microbes;
- and
- c) contacting said stressed microbes with a second concentration of a biocide for a second period of time, wherein said biocide kills said stressed microbes at a concentration that is lower than would be needed with simultaneous treatment with said ATP-reducing agent and said biocide.
18) A method of killing microbes in an industrial water, the method comprising:
- a) contacting microbes present in an industrial water with a first concentration of an ATP-reducing agent;
- b) waiting a first period of time to significantly stress but not kill said microbes by reducing ATP levels at least 90% in said microbes;
- and
- c) contacting said stressed microbes with a second concentration of a biocide for a second period of time;
- d) wherein said biocide kills said stressed microbes at a concentration that is lower than would be needed with simultaneous treatment with said ATP-reducing agent and said biocide.
24) A method of killing microbes in hydrocarbon equipment, the method comprising:
- a) contacting microbes present in hydrocarbom equipment with a first concentration of an ATP-reducing agent;
- b) waiting a first period of time to significantly stress but not kill said microbes by reducing ATP levels at least 90% in said microbes;
- and
- c) contacting said stressed microbes with a second concentration of a biocide for a second period of time;
- d) wherein said biocide kills said stressed microbes at a concentration that is lower than would be needed with simultaneous treatment with said ATP-reducing agent and said biocide.
Dependencies are inferred from the claim text.