A total of 1,350 wells in North Texas' Barnett Shale, including 600 in Tarrant County, have had a robust output averaging more than 3 million cubic feet of natural gas per day during their peak production months, according to research done by the Powell Shale Digest.

The largest average gas production by any well in one month was more than 17.8 million cubic feet per day from Chesapeake Energy's White South #1H well in southwest Arlington.

And while the Barnett is considered natural gas territory, its crude oil production more than doubled during 2010, primarily as a result of Houston-based EOG Resources' development of "the oil window of the northern Barnett Shale," the digest found.

Here are key findings of the report released Monday by the Fort Worth-based digest, widely considered an authoritative source on the Barnett:

The biggest cumulative natural gas producer among more than 15,000 wells in the Barnett Shale is XTO Energy's TRWD #H 2H in Tarrant County, which has yielded nearly 5.4 billion cubic feet over its 67 months of production through December. In its peak month, the well's daily output averaged more than 6.6 million cubic feet, and in December it still produced more than 1 million cubic feet daily.  Read the entire article in the Star Telegram.