Any of you engineers know how frack water is tested? Is it tested prior to chemical mixing? Is it tested as it leaves the well? Do you test for specific bacteria, or are you just looking for presence/absence?

Source water is tested prior for and minerals or bacteria that could affect the frac fluids.

Presence/Absence for bacteria.

But generally, isn't frackwater treated with various biocides to eliminate bacterial contamination and to stave off the souring of a well?

Why are you putting a K in frac?

Thanks for the replies. Trying to learn as much as I can about the testing procedure. About how much time do you have to hold the culture before you read presence/absence? Is it a 24 hour test? Or is it a 3, 5 or 7 day culture? What do you do if you find a positive? Subculture and ID?

I put a K in it because I don't know any better.

I am not in the oil industry directly, but the water/municipal/environmental industry in West Texas, which means they impact me significantly...so anything I post should be read as "as I understand it indirectly". Someone with more actual experience could and should correct me.


I can almost guarantee they do not subculture. Any testing for presence/absence would be handled by the water labs and their procedures which I would assume are governed by NELAC standards.

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Presence/Absence for bacteria.

But generally, isn't frackwater treated with various biocides to eliminate bacterial contamination and to stave off the souring of a well?

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This, along with the pH, specific gravity, chlorides, sulfates, and other minerals that could affect the fluid recipe to make a gelled and/or crosslinked frac fluid.

For other general information about hydraulic fracturing, check out fracfocus.org.

Water samples for Bacteria are cultured in the lab for 72 hours. The level of bacteria will determine the amount of biocide needed to treat the water.

Bacteria is one of the things we test for. Bacteria exist as SRB's (sulfate reducing bacteria) which can eat your pipe. Another thing we test for is total dissolved solids and the presence of scale causing ions. Basically the mixing of frac water with downhole naturally occurring water can cause scale much like what happens to your faucets at home. We add 'K' or KCL to reduce the swelling clays that naturally exist in the formation. Think about what happens to the clay in your flower beds. Recycled water will sometimes contain KCL or a large amount of saltwater (NaCL) that limits the need for clay inhibitors.

Ok...... 3 day culture. Much like water testing in the pharma industry.

What do the water samples look like? Are they clear, cloudy? Is there a high salt content in the samples?

On average, how many water samples do you think are tested per day?

Per frac or worldwide?

Per frac. And also broken down by pre-frac and post-frac.

Probably 3-6 samples per frac stage for chemicals before and after. They do much more than that for bacteria. They turn bottles until there's none left.

Comeby! - how many per day for bacteria only? I understand they run other chemical tests, but I'm only concerned with bacteria.

I'm also interested to know what is in the water. Is it clear? Does it have a high salt content? Is it loaded with dirt or sand? If you were to load the sample into a sensitive instrument for bacterial screening, would the components in the water cause "background noise"?

How are the bacteria cultured? Are the samples diluted 1:10 and placed in tubes with a general broth? Or, is a small sample (i.e. 1ml) placed on an agar plate?