Chevron is to acquire Noble Energy in an all-stock transaction for US$13 billion. The deal has not come as a surprise. Chevron demonstrated its willingness to pursue large-scale M&A in its ultimately unsuccessful bid for Anadarko last year. While Noble won't add the same scale, the rationale is equally compelling. And the move echoes Chevron's US$50 billion bid for Anadarko. More Delaware tight oil, an entry into the Niobrara play and diversification into international gas. But the acquisition of Noble will go further than Anadarko would have towards reducing portfolio concentration in Chevron's anchor positions. Chevron is also buying into producing, cash generative assets in this much smaller, more manageable transaction – for a cheaper price tag.