Prior to attacking Pearl Harbor, Japan had seized thousands of miles of territory, yet American embargo especially oil has often been mentioned as the driving force behind the attack/ Is that accurate?

Can you clarify/sharpen your question a bit further? I'm not really clear what you're asking. If the oil embargo was a factor in Japan deciding to go to war with the US in1941? Why war didn't break out earlier over Japan's imperial expansion/ambitions?

As for the role of the embargo in the decision to go to war - Japan's military simply could not have continued to function without oil imports. So, once the embargo was imposed, the Japanese faced a pretty stark choice - meet American demands and give up their ambitions in China, or go to war and seize a source of oil from someone.

Nearest source of oil was the Dutch East Indies. If you take a ruler and draw a line from Palembang, which was the DEI's centre of oil production at the time, to the Japanese home islands - say to Yokohama - you'll find that it passes right thought the Philippines, home back then to Clark air base and Subic Bay naval station, where the US had based significant air and naval assets.

So, even if they'd seized the DEI, the Japanese would have been in a situation where their Sea Lanes Of Communications to their precious, indispensable oil, was passing through an area controlled by a country so hostile to their foreign policy and wars against neighbors, that it was willing to cut off its oil supply over just her war against China.

That this would leave the Japanese extremely vulnerable, and with even worse relations with the US than before, would have been obvious to Japanese policy-makers.