Phillips 66 wasn't the only energy name that Buffett and company bought last quarter. In fact, both of Berkshire Hathaway's newly-initiated positions were energy stocks. The other is no recent IPO, however; it's National-Oilwell Varco ( NOV). Berkshire bought 2.84 million shares in the second quarter, taking on a $183 million stake in the drilling equipment supplier. >>9 Oil Stocks With Hot Prospects NOV isn't a pure play on energy. Instead, the firm provides tools, services, and consumables used to drill for oil and gas. That bodes extremely well for the firm right now, especially while oil prices remain in the high end of their historic ranges. Higher prices mean that pricier oil and gas projects suddenly become economically viable, driving drilling demand, which drives profits for National-Oilwell Varco. To boot, the need for new production capacity is pushing up the need for new offshore rigs, a drilling vessel that NOV specialized in. That should play out well for the firm in the next several years. NOV's expertise is critical. Because the firm has experience in helping oil companies pull commodities out of the ground, it's got immeasurable advantages over upstart rivals emerging overseas -- especially as the average age of oil projects lengthens and E&Ps look to get more life out of them. While an acquisition appetite (most recently with a bid for Robbins & Myers (RBN) this month) has built up NOV's debt load, it's largely offset by a large cash position right now. Investors looking for energy exposure shouldn't ignore the atypical plays like NOV and PSX. NOV is also one of T. Boone Pickens' BP Capital holdings.