You are correct. Two Billion was announced on 5/20/2013. I looked in the 2 quarterly reports since then and it does not appear that any shares were repurchased. At current prices 17% of the shares could be repurchased with the current Buyback plan. I think it is time that management starts buying back shares to raise the stock price.
Back in 06-08 ESV was buying back shares and the price went from 60 to almost 80. Then they decided to build all the new Rigs and the price has gone back down over the last 6 years. If they would stop building Rigs and start buying back Billions in stock this stock would be $90. I hope they get back on the right track.