"Shale drillers squeeze costs as era of exploration ends": Bloomberg.

Bloomberg: “After spending $53 billion on a land binge to find hydrocarbons, the petroleum industry is counting on technological innovations — better imaging data, speedier and longer horizontal drilling, among them — to ramp up the flow of oil and gas from U.S. shale fields where they’re drilling more than 10,000 wells a year.” “The techniques are embraced by the biggest producers from shale such as Chesapeake Energy Corp. and Newfield Exploration Co. to boost shareholder returns by shifting money from exploration, which is winding down, into what’s known in industry parlance as manufacturing.  ….“Now that all of the established shale plays are known, companies can start focusing on the economics of these plays,” said Eric Gordon, who helps manage $35 billion at Brown Advisory Inc. in Baltimore. “They are under pressure to reduce drilling time and operating costs.”
Independent U.S. oil and gas companies — those that focus on production and don’t refine crude into fuels and chemicals — ended 2012 with an average cash-flow deficit of $1.5 billion, compared with an average surplus of $386 million for the world’s biggest energy producers.
….Chesapeake, the world’s largest driller of horizontal shale wells, said as early as March 2012 that all of the major untapped petroleum deposits in the continental U.S. had been discovered.”