What oil is Warren Buffett buying?

I'm curious, what specific type of oil investment is the legendary investor Warren Buffett making? Is he venturing into the traditional oil and gas sector, or is he exploring alternative energy sources such as biofuels or renewables? And if so, what factors might have influenced his decision to invest in this particular area of the oil industry? As an avid follower of Buffett's investment strategies, I'm eager to understand the rationale behind his latest move and what it could potentially mean for the broader oil market.