The hidden war for oil always goes on. However, Russia now has so many different problems that it hardly dared to openly fight for oil. Now Russia has shown obstinacy and has not agreed to reduce oil production so that its price does not fall too much. However, after some time, Russia will be forced to agree on this with Saudi Arabia and the UAE, when they assess the possible losses.
Putin now imagines himself to be the most powerful emperor in the world, that he began to make a lot of political mistakes.
Putin makes many mistakes, not because he considers himself powerful, but because he has been sitting at the head of the country for more than 20 years, and is going to sit for at least another 15 years. And he will fight for oil with all his might, because the entire economy of Russia is oil and gas production.
In international relations, there are no eternal friends and foes, only eternal interests. In the current geopolitical and geo-economic conditions, especially the United States with Trump and "American First", I think the policy taken by Putin to disagree with Saudi Arabia is rational.
The reason is that Mohammad bin Salman chose to acquire Lockheed Martin's Terminal High Altitude Area Defense (THAAD) system instead of the one promoted by Russia after six US-made Patriot batteries battalions failed to detect drone and missile attacks at Saudi Arabia's two main oil facilities.
Source:
https://insidearabia.com/playing-for-higher-stakes-saudi-arabia-gambles-on-oil-war-with-russia/Economically, in my opinion, the decision taken by Saudi Arabia is a mistake, because Saudi Arabia only thinks about meeting short-term economic needs rather than long-term security. As for Russia First, this policy has been carefully considered because, since the fall of the last oil price, Russia has been right and strengthened its budget, thus providing great financial protection. Second, high crude oil prices will only benefit US shale oil producers, if the price of crude oil is low it will cause economic losses to the United States and damage its ability to use international coercive devices in the form of sanctions. This is related to Russian interests (ROsfnet) in Venezuela.