What caused the uptick in Texas fields in 2010? New technology? Bringing back online old slow producing wells?...........
The same steerable horizontal drilling combined with hydraulic fracturing, along with a state government that is condusive to business and trying to grow jobs with reasonable tax structure, reasonable regulations and not constant changes in both. There is shale fields in several states, including California and Alaska. But not all states work to grow business and the associated jobs.
About half of the operating drilling rigs in the US are currently in Texas.
North America Rig Count
http://investor.shareholder.com/common/download/download.cfm?companyid=BHI&fileid=541838&filekey=F32D8ADF-5923-4555-ABE5-5D072FE8BF3A&filename=Rigs_by_State_021012.pdf
For exact locations and other data:
http://gis.bakerhughesdirect.com/RigCounts/default2.aspx