emirate
All of the Gulf countries are "oil rich" -Possibly Saudi Arabia most.
The Persian Gulf.
The Persian Gulf
Texas
Off the Gulf Coast.
Louisiana
Oil makes 70% of the country's income, not as rich as other Arabian gulf countries, stable development.
To prevent Iraq from conquering its oil-rich neighbors
This question would seem to be asking about the Persian Gulf. The gulf is part of the Indian Ocean and the lands surrounding it contain rich petroleum reserves.
You are likely referring to the Persian Gulf, but the description also suffices for the Gulf of Oman.
Gulf Oil was created in 1901.