Final answer:
Approximately 80% of the world's readily-accessible oil reserves are located in the Persian Gulf region, with major contributions from light crude oil reserves in countries like Saudi Arabia, Iran, Iraq, the UAE, and Kuwait.
Step-by-step explanation:
About 80% of the world's readily-accessible oil reserves are located in the Persian Gulf region. These reserves are predominantly found in countries such as Saudi Arabia, Iran, Iraq, the United Arab Emirates, and Kuwait. These oil reserves are sought after for being mainly light crude oil, which contains more of the useful shorter-chain hydrocarbon molecules like octane.
The geopolitical implications of this distribution are significant, as many of the countries with the largest oil reserves are not the ones with the highest consumption. For example, the proven oil reserves in the United States amount to 35 billion barrels, which pales in comparison to the vast oil reserves in the Persian Gulf. The disparity in oil reserves underscores the geopolitical power that these Middle Eastern countries hold over global oil markets.