Eagle Ford Shale Maps of Oil Zone

Eagle Ford Shale Maps

Below are several maps of the Eagle Ford shale.

The name of the oil and gas play is frequently misspelled as “Eagleford”. The correct spelling is what is seen on this website.   The Eagle Ford shale takes it’s name from the small town of Eagle Ford Texas, where it outcrops in North Texas near Dallas.

The following map is from Ross Smith Energy Group . They do not sell maps to the public.  It appears here with their permission.   This Eagle Ford shale map shows the trend from Mexico (where it obviously continues across the border as well) to East Texas. It shows the low pressure, oily section in the northern region, the condensate section in the middle and the dry gas section at the lower half. Although it is difficult to read the gray areas are Austin Chalk producing areas. Wherever you find Austin Chalk production you are likely to find Eagle Ford oil as well.

Here is a map from EOG Resources showing the oil, gas and condensate zones of the Eagle Ford Shale as well as some initial production rates. (Note, IP, or initial production rates should not be confused with long term production rates). You can click on the map for full size.

Below is a map from the U.S. Energy Information Administration. The map is a little out of date when it comes to showing well locations, since dozens of new Eagle Ford shale wells have been drilled since it was made. It does however provide a good picture of Eagle Ford shale thickness and extent.


The following Eagle Ford shale map from the Texas Railroad Commission shows counties with permitted and completed wells as of August, 1, 2011.


An Eagle Ford Shale isopach map showing thickness. From University of Texas Bureau of Economic Geology.

Lower Eagle Ford Shale Thickness Map

Note: The lower (transgressive) Eagle Ford Shale has higher clay content and higher overall organic content.

Eagle Ford Shale thickness map

Upper Eagle Ford Shale Thickness Map

The upper (regressive) Eagle Ford Shale has lower overall clay content and higher overall carbonate content.

thickness map Eagle Ford Shale

(From Texas Bureau Of Economic Geology, University Of Texas)

Below is an Eagle Ford shale map showing the depth of the top of the formation.

Below, Eagle Ford shale thickness maps from Petrohawk Energy. Thickness in feet of the Eagle Ford shale in Atascosa, Gonzales, Wilson, Karnes and DeWitt counties is shown.


The map below, from Marathon Oil, shows the Eagle Ford shale divided into four zones, dry gas, wet gas, volatile oil and black oil. While the distinctions between “black oil” “volatile oil”, condensate and “wet gas” are something even petroleum engineers can’t seem to agree on, basically “volatile oil” is lighter oil that evaporates faster than heavier crude. Lighter crude oil (higher API gravity) typically trades at premium prices since it is more easily refined into gasoline, etc. Marathon Oil purchased the acreage shown in blue from Hilcorp Resources Holdings for approximately $20,000 an acre.

The Carrizo Wilcox aquifer is an important source of water for much of the area where the Eagle Ford shale lies, and a primary source of frac water used in completing wells. Below is a map of the Carrizo water sand.

Below are charts showing the Cretaceous geology of South Texas, including the Eagle Ford shale formation. The Pearsall shale is located deeper than the Glen Rose formation at the bottom of the chart.

  Stratigraphic column Pearsall Shale South Texas

The Pearsall Shale, located a couple of thousand feet below the Eagle Ford shale could be “the next big thing.” Unfortunately there are few geological maps of the Pearsall shale available online. Below is an old isopach map of the Pearsall shale from a geological paper published in the 1970’s.

Pearsall isopach map

Pearsall Shale Depth Map (isopach) from Loucks, 2002.

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