A few operators approached our Technical Sales Professional, Dustin Sockwell, after experiencing souring issues post-frac. The fracs showed great treatment of bacteria on surface but after testing the flowback 30 days later, the presence of sulfur reducing bacteria was discovered, suggesting these microbes were not controlled for the duration of the frac. Dustin offered some words of wisdom for other operators experiencing souring issues post-frac. Within the frac process it is important to select the right biocide for the job and to test the effectiveness for the duration of the frac job. While all biocides provide a method of kill, some offer a quick kill, immediately knocking down the microbial load, while others are work horses, offering long term reliability. The wells in question used chlorine dioxide treatment on surface immediately killing and dropping the bacteria count, which is ideal when introducing the source water into the formation. The challenge is this fast-acting biocide is used up on surface, leaving little to no residual biocide to kill microbes that make it past the initial treatment. Biocide selection is so important within the Frac process especially when using produced or commingling waters. Complete a kill study at least to the point of flowback time to ensure the kill takes into consideration source water, microbial load, length of time and overall desired kill.
Dustin Sockwell, Technical Sales Professional