Wednesday, January 14, 2015

Are we managing the hazards of hydrogen sulfide at the right place?

In the december issue of Hydrocarbon Processing there was an article titled "Manage hydrogen sulfide hazards with chemical scavengers". The article describe quite a number of chemicals for reacting hydrogen sulfide to create less toxic compounds. The compounds, which react with hydrogen sulfide are called scavengers. The idea is to reduce the concentration of hydrogen sulfide to a level, where a release is less serious.

From the article it is clear, that the place where in the chain from downstream exploration to upstream products at which the hydrogen sulfide is removed varies quite a bit. It can be done in the bitumen, the crude oil, the naphtha, the gas oil, the fuel oil. I would of course like to see the hydrogen sulfide problem managed / solved as close to the well as possible in order to reduce or eliminate the risk of exposure during subsequent upstream processing. However, the article seem to indicate, that this is not always possible or desirable, since the chemical scavengers used sometimes make upstream processing more difficult.

With the many smaller shale oil wells coming on stream the hydrogen sulfide problem has increased. There is two reasons for this. One is that the sulfur content from these wells according to some source appear to increase as the well has been in production. Another is that the crude from these wells are often not transported by pipeline to refining, but by rail cars. There are properly many reasons for this, but it appears a contributing factor has been the speed at with this type of production has increased.

Even though significant improvements in rail car construction has happened over the last decades, so it is no longer unusual to see a rail car flipped over without a single drop being released, the statistics appear to indicate, that there is higher risk of a release during rail car transport, than by pipeline transport. If transport of crude oil by rail car continue to increase and hence increase the risk of exposure to people, who live along the transport corridor, then oil industry most improve the downstream treatment for hydrogen sulfide removal.

If industry does not act we will likely see more events like the one in Quebec, and the result will be a public demand, that the authorities take action. What do you think?