Lower oil prices, while good for the broader US economy, are a threat to what has been a surprising and dramatic surge in oil production in the US, and to drilling communities that have come to depend on oil money. With oil prices low and showing no sign of an immediate rebound, the industry is beginning to pull back on spending. Oil prices have dropped around 30 percent since summer highs, raising fears among producers across the globe. Yet, many oil majors are relatively diversified, with large holdings downstream. For example, ExxonMobil and Chevron have been insulated in the third quarter because of their large holdings in refining. Steep declines in oil prices may hurt their production sectors, but with lower priced oil as an input, big oil’s refining assets become more profitable. […]