Inhibition of bacterial growth in pipelines

Abstract

Use fresh water or water with sufficiently reduced salinity to trigger burst of bacterial cell wall due to osmotic pressure gradient. Combine the freshwater with conventional biocide treatment and pigging to increase the likelihood of killing the bacteria responsible for reservoir souring.

1 . A method for remediation of microbially induced corrosion in a section of a pipeline used to transport water with a total dissolved salt concentration of at least 0.25 M expressed as sodium chloride dissolved, the pipeline having a volume, where bacteria that induce corrosion grow on the inside surface of the pipeline and have an intracellular tonicity, comprising:
 a) performing a pig run in the section of the pipeline;   b) subjecting the inside of the section of the pipeline to a hypotonic water compared to the intracellular tonicity of the bacteria growing on the inside surface of the pipeline sufficient to cause osmotic lysis in the bacteria.   
     
     
         2 . A method for remediation of microbially induced corrosion in a section of a pipeline used to transport water with a total dissolved salt concentration of at least 0.25 M expressed as sodium chloride dissolved, the pipeline having a volume, where bacteria that induce corrosion grow on the inside surface of the pipeline and have an intracellular tonicity, comprising: b) subjecting the inside of the section of the pipeline to a hypotonic water compared to the intracellular tonicity of the bacteria growing on the inside surface of the pipeline sufficient to cause osmotic lysis in the bacteria. 
     
     
         3 . The method according to  claim 1 , wherein the bacteria are halotolerant or halophilic bacteria. 
     
     
         4 . The method according to  claim 1 , wherein the tonicity of the hypotonic water is 0.1 M or less. 
     
     
         5 . The method according to  claim 1 , where the hypotonicity of the water is at least half the intracellular tonicity of the bacteria. 
     
     
         6 . The method according to  claim 1 , where the bacteria are sulphate-reducing bacteria. 
     
     
         7 . The method according to  claim 1 , wherein under b) the inside of the section of the pipeline is subjected to one or more pulses of hypotonic water. 
     
     
         8 . The method according to  claim 1 , wherein the section of the tube is in contact with hypotonic water for at least 30 seconds, such as at least 1 minute, such as at least 60 minutes. 
     
     
         9 . The method according to  claim 7 , wherein the one or more pulses of hypotonic water are enclosed by a plug on the leading ( 105 ) end of the pulse of hypotonic water, and/or by a plug on the trailing end ( 106 ) of the pulse of hypotonic water. 
     
     
         10 . The method according to  claim 9 , wherein the plug is liquid and has a viscosity of more than 2 cP, such as between 2-10 cP. 
     
     
         11 . The method according to  claim 1 , wherein the one or more pulses of hypotonic water each have a volume of 20% or less of the volume of the section of the pipeline. 
     
     
         12 . The method according to  claim 1 , wherein the volume of the section of the pipeline is at least 15 m3. 
     
     
         13 . The method according to anyone of  claim 1 , wherein one or more additives are added to the hypotonic water, the one or more additives selected from the list consisting of: chemical biocides and/or bacteriophages. 
     
     
         14 . A use of a hypotonic water for remediation of microbially induced corrosion in a section of a pipeline situated in connection with an oil reservoir or a section thereof, the pipeline being used to transport water with a total dissolved salt concentration of at least 0.25 M expressed as sodium chloride dissolved, the pipeline having a volume, where bacteria that induce corrosion grow on the inside surface of the pipeline and have an intracellular tonicity that is at least 3-fold higher than the hypotonic water. 
     
     
         15 . The method according to  claim 2 , wherein the bacteria are halotolerant or halophilic bacteria. 
     
     
         16 . The method according to  claim 2 , wherein the tonicity of the hypotonic water is 0.1 M or less. 
     
     
         17 . The method according to  claim 2 , where the hypotonicity of the water is at least half the intracellular tonicity of the bacteria. 
     
     
         18 . The method according to  claim 2 , where the bacteria are sulphate-reducing bacteria. 
     
     
         19 . The method according to  claim 2 , wherein under b) the inside of the section of the pipeline is subjected to one or more pulses of hypotonic water. 
     
     
         20 . The method according to  claim 2 , wherein the section of the tube is in contact with hypotonic water for at least 30 seconds, such as at least 1 minute, such as at least 60 minutes.