Oil production has the problem that increasing in oil production requires spending money that will only pay off if the price of oil remains high for several years. Cheap producers like Saudi Arabia know this, and so try to make the price fluctuate with enough lows to wipe out expensive oil producers, and enough highs to get rich themselves. More marginal properties would make money, but it is hard to survive the lows.
Therefore government policy that produces an effective price floor encourages the production of otherwise marginal oil. This is effectively a bet that increased tax revenue from future production is worth the risk of that tax guarantee. And in the short run you get an increase in jobs for no actual outlay of resources. Which is a trick any politician can appreciate.
That said, it remains a bad policy. Once implemented, lobbying efforts are virtually guaranteed to expand government support until the public is guaranteed to lose money. Doubly so because oil producers can now play one government off against another in a race to see who can offer more. (Sports teams have mastered that particular game...)