EIA Updates Eagle Ford Maps

The U.S. Energy Information Administration (EIA) has released new maps that include updated information for Eagle Ford derived from producing wells from January 2000- June 2014 based on The maps are categorized in the following geological parameters.

Initial GOR

This map shows the detailed production in relation to the natural gas to oil ratio (GOR) of the play.

Oil to gas ration map for Eagle Ford 2015

Play Footprint

This map shows the four boundaries of the Eagle Ford Play

  1. North - This boundary is determined by the temperatures at which oil is generated from rock and stops at 3650 feet in Frio County and counties east, and in Maverick and Zavala counties from 650 to 2900 feet.
  2. South - This boundary follows the Sligo Reef Margin.
  3. Northeast - This boundary where the lower Eagle Ford thins and grades into more silica-rich units of the Pepper Shale of the East Texas Basin
  4. West - This boundary is marked by the border with Mexico
EFS boundaries map: 2015

Elevation Contours

This structure map characterizes the depth of the play and represents the minimum drilling depth to reach the top of the Eagle Ford formation.

The Eagle Ford formation is divided into upper and lower units, and the top of the lower unit is considered the best proxy for the source rock; however, due to a lack of density and distribution of the depth to the top of the lower Eagle Ford formation, this map represents an approximation of the elevation of the top of the upper Eagle Ford unit.
Eagle Ford elevation map 2015

Thickness Contours

This map provide a rough estimate of the thickness of the play, which is used to estimate resource volumes, such as oil- or gas-in-place estimates, in combination with other information such as porosity, pressure, and geologic history.

Eagle Ford thickness map

How Thick Is the Eagle Ford?

The Eagle Ford Shale's thickness varies several hundred feet across the region and there's not a significant correlation to thickness and well productivity. The play's thickness ranges from less than 100 ft to 400 feet near the Mexico border. The average thickness is 250 ft across the most commonly targeted portions of the play.

Eagle Ford Thickness Map
Eagle Ford Thickness Map

Read more at our Eagle Ford Geology page.