I did a study on this just after the turn of the century along the I-20 area East of Shreveport. I can't remember the number of wells and don't have time right now to look for it but the H2S content that I found was 4 parts per million. I think that it was Koch that gave me the info, they said they didn't moniter it until it reached a level of 10 parts per million. They said that they washed it with an amine treatment then mixed it into the line with sweet gas.
I found my research, the H2S content was 6 parts per million. I don't know to what extent I went to but I know that it was in the North Shongaloo Red Rock and Carterville fields located in Bossier and Webster Parishes, North of I-20. I found that 104 well had been drilled into the Smack and that 70 of them were still producing. This work was done in May & June of 2000. The first wells were drilled in 1957.