The EIA (U.S. Energy Information Administration) issued findings in February 2014 showing most wells drilled in the Eagle Ford have increasingly targeted oil-rich areas since production began in 2009. The larger bubbles represent higher initial production rates.

Also read: Pioneer Hits Record Q4 Production in the Eagle Ford

Low GOR Wells - "Sweet Spots" in the Eagle Ford

*There is no sound associated with the animation

The animation in the video above shows the

GOR*

(gas to oil ratio) of wells drilled in the Eagle Ford since 2009. Sweet spots for oil production are represented by the green bubbles, and appear along the northern portion of the play.

Oil companies in the Eagle Ford are keenly aware of this data. For instance, Pioneer Resources announced in February 2014, plans to drill 45 wells in the upper (northern) portions of the Eagle Ford Shale.

Economics of Drilling Lower GOR Wells

Certainly, the fact that more wells are being drilling for oil in the Eagle Ford shouldn't come as much of a surprise. With the current price of oil hovering around ~$100 bbl  and the stagnant price of natural gas over the past several years, the pattern simply reflects the free market.

Depth of Reservoir Has An Impact on Production Yield

The distribution of initial GORs from Eagle Ford wells generally corresponds to the depth of the reservoir. Deeper wells (up to 15,000 feet) to the southeast have higher initial GORs, or a relatively greater share of natural gas, while the shallower wells to the northwest (below 6,000 feet) have lower initial GORs, or a relatively greater share of oil.

GOR: Gas to Oil Ratio (GOR) is a term used to describe the ratio of volumetric flow of produced gas to the volumetric flow of crude oil for crude oil and gas mixture sample. If a hydrocarbon producing well produces a high GOR mixture, it is identified as a gas well. If GOR is low, it is identified as an oil well.

Read more at EIA.gov