The ratings on Irving, Texas-based ExxonMobil Corp. reflect Standard&Poor's Ratings Services' view of the company's "excellent" business risk profile, which is based on its outstanding competitive positions in all facets of the oil and gas industry, and its "minimal" financial risk. ExxonMobil operates in three primary business segments: upstream, downstream, and chemicals. Upstream (its exploration and production (E&P) unit) contributes the most (by far) to profitability and cash flow. For the first nine months of 2012, the E&P segment accounted for more than 60% of the company's consolidated net income. At year-end 2011, ExxonMobil's proved reserves totaled 25 billion barrels of oil equivalent (boe)--the largest among the "supermajors" (the six largest non-state-owned oil companies in the world). A
