yes, they also involve in the maintenance for oil n gas machineries, but, in my opinion, the current hot money flowing into oil n gas stocks is just because the production of oil has reduced, hence making the price up, but this doesn't mean the demand for oil has gone up, so, in short, if there's no demand for oil, then the digging&refining of oil didn't increase, and the maintenance also didn't increase, so that's why frontken also gets dragged down in these few days.(i am holding frontken fyi)