"It's also a bet on the fact that the Permian Basin is what it is cracked up to be," the chairman and CEO Berkshire told CNBC's Becky Quick. But "oil prices will determine whether almost any oil stock is a good investment over time."
"If [oil] goes way up, you make a lot of money," he added.
Occidental revealed on Tuesday that Berkshire had committed to invest $10 billion in the company to help fund its proposed acquisition of Anadarko Petroleum. Berkshire would make the investment by purchasing 100,000 shares of preferred stock, which pays out an 8% annual dividend.
Buffett was willing to invest $20 billion to help Occidental seal the deal, sources told CNBC's David Faber. Occidental revised its bid to purchase Anadarko after the international oil and gas driller agreed to sell its business to Chevron last month for $65 a share in a 75% stock and 25% cash deal worth $50 billion including debt.
Asked why Berkshire wouldn't just buy Anadarko itself, Buffett said, "That might have happened if Anadarko came to us, but we wouldn't jump into some other deal that we heard about from somebody else coming to us seeking financing."
Later in the interview, longtime investing partner and vice chairman Charlie Munger responded to the question as well, saying, "Nobody asked us to."
Buffett added he previously never had any sort of communication with Anadarko.
—CNBC's Tom DiChristopher contributed to this report.