As you suggest in the question, the main Japanese war aim was to capture the oil fields of Indonesia, as well as the natural resources of Malaysia. These were under the control of the Netherlands and the UK respectively. The main sea lanes between Japan and these resources run past the Philippines, which were an American colonial possession at the time. If Japan went to war without neutralising the Philippines, and America entered the war, Japanese forces in Indonesia would be cut off, and resources would be unable to flow back to Japan. The Japanese military thought it quite likely that the USA would enter a war in South-East Asia. As a result, they needed to attack the Philippines as a prelude to capturing Indonesia. However, attacking the Philippines would provoke an American response. The Japanese plan to deal with this response focussed around forming a defensive perimeter in the Central Pacific, which would attrit the American counter-attack. The weakened American fleet would then be destroyed in a single decisive battle, and Japan could sue for peace from a position of strength. However, many of the islands needed to form this defensive perimeter were held by the British Empire or the USA. These islands had to be captured without the American Pacific Fleet intervening. Attacking Pearl Harbor prevented the fleet from sortieing to interfere with these landing operations, and the subsequent fortification.
Source:
Toland, J. , Rising Sun: The Decline and Fall of the Japanese Empire 1936-1945, Pen and Sword Military, 2005
Both the United States and Japanese naval strategists believed in a concept known as the Mahanian Battle.
Alfred Thayer Mahan's concept that naval power would be concentrated so that one navy would strike another navy with an overpowering knockout blow. The winning navy could then control a vast area of an ocean, control the sea lanes and force the losing navy into accepting a peace.
The Japanese tried that at Pearl Harbor, against the British at Singapore (sinking of Prince of Wales and Repulse) then the US and Japan tried it at Midway, then again at the battles off Guadalcanal.
To understand this, look at the evolution of War Plan Orange - https://en.wikipedia.org/wiki/War_Plan_Orange
Mahan - https://en.wikipedia.org/wiki/Alfred_Thayer_Mahan#Impact_on_naval_thought
http://www.stengerhistorica.com/History/WarArchive/Ritterkreuztraeger/Henke/NavalTheory.htm