That kind of reinforces what everyone has been saying - from discovery to first oil is 3-5 years. Building a refinery is 3-7 years after recovery. The key is that you know you have a major resource after 3-5 years and may reconsider attacking the two largest powers on the planet to get more oil.
Did you attend the
Gozen Kaigi (imperial conference) perchance? You show the same casual disregard of logistics and economics that they did
Let's see why Japan went to war:
One of the main reason Japan set itself on the path to war was due to its lack of free press and the elite wanting the benefits of modernity without all the social and institutional changes that comes with it (rule of law, power sharing, free press). Even events that were great for Japan such as the victory over Russia, Washington Naval Treaty and more were presented by the nationalist Japanese press (influenced by its elites) as hideous bullying (despite the fact that it was the Japanese leaders who asked for American mediation in 1905 due to exhaustion and the fact that Japan couldn't possibly hope to match America in a naval arms race so limitations were great). The same leaders who couldn't achieve outlandish ambitions also couldn't take responsibility and with their connections in the press blamed away.
By the 1930s, extreme nationalism and racism was rampant in Japan which when combined with a conscription law that allowed one to purchase exemptions/substitutes meant that the poorest parts of society hardest hit by the great depression now made up the bulk of the army. (silk growing was a major export and lifeline for many poor farmers, especially concentrated in the north. Thing is silk is a luxury product whose demand plummeted during the depression). These were the same men who were treated in a feudal manner by their landlords, complete with intimidation and corporeal abuse, habits they brought with them into the army. To these conscripts liberalism and democracy was the cause of their misery (as opposed to trade, or the deprivations of their semi-feudal elite). This was an army that made corporeal punishment and arbitrary punishments mandatory under the simplistic and naive idea of making them "vicious fighters who would vent their pent-up rage against the enemy ".
Having by now taken on a life of its own, the racism, extreme-nationalism, and propensity for violence political assassinations became common-place and were given a free-hand by the elites which scorned rule of law and civilian government. Eventually it got so bad that the choice was to either have the junior officers killing the civilian government in Japan or starting wars in China, not that the politicians had much choice. Unwilling to obey civilian nor higher military authority, extremely violent, racist, and nationalist were the troops Japan sent to the Asian mainland with disastrous consequences.
Japan didn't choose to go invade Manchuria nor China proper, Japanese officers made their own conquests and the civilian government was left scrambling to come up with excuses like the "Greater Co Prosperity Sphere". Internationally during the political climate of the depression few except for the Americans with its extensive commercial interests cared about China yet the Japanese would inadvertently make fools of everyone who believed their promises of restraint and peace as its officers would launch another invasion in a month or so. Even worse the army consistently committed atrocities against the civilian government galvanizing world opinion against them, even if the Chinese were far away it disgusted people on some base human level to hear of the brutalizing, slaughter, and rape of thousands. It was the same brutality that made collaboration nearly impossible, guaranteeing low-scale warfare and resistance where ever they went.It went even further to direct attacks against Western concessions and forces within China (ie: Panay incident) by the same officers unaccountable to Tokyo.
During this process of undefined and unplanned military expansion it was politically impossible to pull back: The threat of assassination, the sunk-cost fallacy of all the Japanese lives already lost in conquest, the extremely contorted memories of foreign injustices and perceived threats made the prospect of peace improbable. All the while, the wars in China and occupation of Manchuria was never profitable (useful yes, though far from profitable) was slowly bankrupting Japan. Even without the embargoes the Japanese war machine was grinding to a fiscal halt, something they couldn't accept IOTL and hence war since their military was the only assets they had.
An oil supply by the late 1930s, when taking into account the surplus of world supply pre-war and relative cost of imports wouldn't make a dent on a decade of military expenditures, more money would've just meant conquering more useless land full of Chinese partisans. IOTL Japan's attempt to build a refinery on the mainland costed them the equivalent of 2 Yamatos and upon completion severely under-performed due to a lack of technical expertise and equipment-where in the Imperial budget do you get that from? Also, I'm supposed to believe that the same men who stumbled onto the edge of war, who didn't bother building enough tankers and merchantmen for war, who planned on a war based on racist wish-fulfillment, would bother with long-term investments such as oil, pipelines, and refining capacity at a time when oil was dirt cheap and the projects were uneconomical? They didn't build synthetic rubber plants for similar reasons of economics and never saw the need to until it was too late.
The reason Japan went to war was its domestic situation, which after the first assassins were let off with a slap on the wrist became a runaway boulder hurling towards the abyss. Oil won't change that, it won't even make a dent in the national budget nor the climate of politics by assassination.