As far as I am aware, there are no sanctions on oil or gas yet.
Instead, the sanctions come in two flavours: one is the part where Russian banks are cut off from the international banking system and Russian overseas assets (read: money) are being frozen; the second is restrictions on the trade of certain goods. The former needs little explanation.
Importantly, both the import and export of certain goods into/out of a sanctioned territory may be sanctioned and the lists need not be identical. When choosing which goods cannot be imported into the sanctioned territory (from the sanctioning nations) the following aspects are considered:
- how much the sanctioned economy relies on importing these goods as opposed to self-production
- whether the sanctioning nations supply a significant fraction of these goods
- who will be most directly impacted by the lack of these goods (i.e. sanctioning food imports will likely impact the people directly, while sanctioning materials used for high-tech industry solutions will impact the industry and proprietary class more)
Conversely, when considering exports from the sanctioned territory the considerations are almost opposite:
- how much do the sanctioning economies rely on these goods from the sanctioned country; can they cover their demand by tapping into other markets easily
- how much does the sanctioned economy rely on exporting them; can they access other markets easily
- what impact does the export of the goods have on the exporting economy
In the case of Russia, most of the nations doing the sanctioning (the US, Canada, Japan, South Korea, Australia, the EU, etc.) are highly developed nations while Russia itself is typically not classified as highly developed and instead still strongly relies on natural resources. Therefore, prime targets for goods that can no longer be exported out of Russia would be oil, gas and minerals. On the other hand, prime targets for import sanctions would be high tech, manufactured end-products and the like, which Russia is unlikely to be able to source elsewhere and cannot reasonably quickly source domestically.
This in turn means that reducing Russia's income by hitting its exports is only part of the puzzle. A much more significant portion is reducing Russia's ability to import other goods that it might need. For example, it is highly likely that Russian airlines will struggle to maintain their Airbus and Boeing jets as many of the necessary parts might be sanctioned (this was the case for Iran and led to an amusing issue when a long-distance flight experienced a technical issue and performed a safety landing in Iran: flying in the necessary parts to repair that aircraft might have run afoul of the sanctions. I do not remember how that story ended).
So of course, a small part of the sanctions (sanctioned exports, thereby lost income for Russia) will be offset by higher oil and gas prices meaning these hitherto unsanctioned goods will be more profitable; but there is far more to the big picture than just this minor issue (which may well have been priced in a priori).