After we identified the trends discussed above, we initiated a plan to build and maintain the largest inventory of onshore drilling opportunities in the U.S. Recognizing that better horizontal drilling and completion technologies, when applied to various new unconventional plays, would likely create a unique opportunity to capture decades worth of drilling opportunities, we embarked on an aggressive lease acquisition program, which we have referred to as the “gas shale land grab” of 2006 through 2008 and the “unconventional oil land grab” of 2009 through 2011. We believed that the winner of these land grabs would enjoy competitive advantages for decades to come as other companies would be locked out of the best new unconventional resource plays in the U.S. We believe that we have executed our land acquisition strategy with particular distinction. At September 30, 2012, we held approximately 15.1 million net acres of onshore leasehold in the U.S. and have identified more than 30,000 drilling opportunities on this leasehold. We believe this extensive backlog of drilling, approximately 20 years worth at current drilling levels, provides strong evidence of our future growth capabilities. We further believe that the U.S.-based undeveloped leasehold acquisition phase is now substantially complete and are forecasting to spend significantly less on new leasehold in the coming periods as compared to recent years.​​