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.
Play Footprint
This map shows the four boundaries of the Eagle Ford Play
- 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.
- South - This boundary follows the Sligo Reef Margin.
- 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
- West - This boundary is marked by the border with Mexico
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.”
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.
