I don't think I see a fit substitution in the works. Tbh, Russia is one the largest suppliers of oil to the West and they know this. Should I call this act a form of retaliation for imposing sanctions? I think not. Probably this is a wake up call for the US. I think Iran, Canada, The UK and even Norway or Denmark could be considered to fill in the blanks in the meantime.
Keyboard warriors are coming up with all sort of scenarios to replace the Russian gas. What they don't understand is that designing and implementing new projects to extract natural gas may take many years. And even after that, there is no guarantee that the natural gas prices will remain high enough to make these profits profitable. And secondly, replacing pipeline gas with LNG can be very tricky. There is only a limited number of LNG tankers available. And the same can be said about the LNG terminals as well. In short, there is no quick fix solution.