The Eagle Ford Shale is a hydrocarbon producing formation of significant importance due to its capability of producing both gas and more oil than other traditional shale plays. It contains a much higher carbonate shale percentage, upwards to 70% in south Texas, and becomes shallower and the shale content increases as it moves to the northwest.
The high percentage of carbonate makes it more brittle and “fracable”. The shale play trends across Texas from the Mexican border up into East Texas, roughly 50 miles wide and 400 miles long with an average thickness of 250 feet. It is Cretaceous in age resting between the Austin Chalk and the Buda Lime at a depth of approximately 4,000 to 12,000 feet. It is the source rock for the Austin Chalk and the giant East Texas Field. The name has often been misspelled as “Eagleford”. A great picture can be found at the Energy Information Administration (EIA) http://www.eia.gov/oil_gas/rpd/shaleusa9.pdf which shows the structural contours and windows for the oil, wet gas/condensate and dry gas. There were 72 producing oil leases in 2010 and 40 producing oil leases in 2009. There were 67 producing gas wells in 2009 and 158 producing gas wells in 2010.
History of the Eagle Ford
It is named for the town of Eagle Ford, Texas where it can be seen on the surface as clay soil. Eagle Ford, Texas is approximately 6 miles west of Dallas, Texas. An outcrop of the Eagle Ford Shale can be seen in the Dallas-Fort Worth Metroplex. Wikipedia shows a nice picture of the outcrop of the Austin Chalk and Eagle Ford shale at the following link http://en.wikipedia.org/wiki/File:Austin_Chalk_-Eagle_Ford_Contact.JPG
Petrohawk drilled the first of the Eagle Ford wells in 2008, discovering in the process the Hawkville (Eagle Ford) Field in La Salle County (District 1). The discovery well flowed at a rate of 7.6 million cubic feet of gas per day from a 3,200-foot lateral (first perforation 11,141 feet total vertical depth) with 10 frac stages. Originally, there were 30 plus fields, however, due to field consolidations, the number of fields has been reduced to currently 16 fields located within the Railroad Commission Districts 1 thru 6 and the fields cover 24 counties . The wells in the deeper part of the play deliver a dry gas, but moving northeastward out of District 1 and updip, the wells produce more liquids. One of the fields discovered in District 2 is actually an oil field (Eagleville (Eagle Ford)). The major operators joining Petrohawk in drilling the Eagle Ford Shale Play are Anadarko, Apache, Atlas, EOG, Lewis Petro, Geo Southern, Pioneer, SM Energy and XTO to name just a few.
Natural gas is a relatively clean burning energy source. Producing additional domestic natural gas may reduce dependence on foreign energy sources. For more information about natural gas, please visit the United States Department of Energy, Natural Gas home page.