We define reactions uniquely depending on the reactants and products. Here are examples related to your question.
Formation: Na(s) + (1/2)Cl$_2$(g) $\rightarrow$ NaCl(s)
Lattice Formation: Na$^+$(g) + Cl$^-$(g) $\rightarrow$ NaCl(s)
Solution: NaCl(s) $\rightarrow$ NaCl(aq)
Hydration: Na$^+$(g) $\rightarrow$ Na$^+$(aq)
Atomization: Na(s) $\rightarrow$ Na(g)
It is less economical to harness this energy/materials. From the perspective of the company, money is better spent on their immediate business needs such as locating large resources or improving the thermodynamic efficiency of their refinery.
Reasons it may be less economical include:
Intermittent flow; flow may be zero for long periods, with intermittent ...
This NASA article discusses some of the common wind tunnel flow visualization methods.
A fog machine generally uses a heated mixture of polypropylene glycol and water. You can test different mixture concentrations in an electric kettle, and use a plastic tube to plumb the fog stream to the locations you are interested in visualizing the flow.
Tufts or pieces ...
I think this is a situation of "the devil is in the details', and of course, cost. In the US, gas from a few wells would not likely be of sufficient volume; but several/many wells could be combined (detail = pipeline plan and control). There are wells, mostly Middle East that do have enough flare gas. As a point of reference the last local power gas ...