Morgan Stanley analysts recently included this chart of crude production costs. Onshore Middle East oil sites are much cheaper to tap than North American shale, which costs about $65 per barrel to extract.
1. ponder-reflect deeply on a subject; I mulled over the events of the afternoon; philosophers have speculated on the question of God for thousands of years; The scientist must stop to observe and start to excogitate.
Verbs of telling, asking, ordering, singing. Synonyms: altercate; argufy; quarrel; dispute; scrap. Context examples: We quarreled over the question as to who discovered America / These two fellows are always scrapping over something. Hypernyms (to quarrel is one way to...): argue; contend; debate; fence (have an argument about something)