The US isn’t really a market for their oil or gas,
That is not at all what the petro dollar is about. It’s about USA ensuring the safety of the GCC countries, and in return the GCC countries are selling oil for USD, this increases international demand for USD to buy oil. GCC countries are then investing most of those dollars back into American companies. If that cycle is broken, demand for USD will decrease dramatically, and a lot of investments would disappear from USA too. Whoever buys the oil is irrelevant, as long as it is paid in USD, the petro dollar is maintained.
That is not at all what the petro dollar is about. It’s about USA ensuring the safety of the GCC countries, and in return the GCC countries are selling oil for USD, this increases international demand for USD to buy oil. GCC countries are then investing most of those dollars back into American companies. If that cycle is broken, demand for USD will decrease dramatically, and a lot of investments would disappear from USA too. Whoever buys the oil is irrelevant, as long as it is paid in USD, the petro dollar is maintained.