Eagle Ford Overview: Part I
Hart Energy, the publisher of “E & P” magazine recently released their “Eagle Ford Techbook” which includes an excellent article by Richard Mason entitled “The Eagle Ford Shale, Energy Titan of the Southwest”. I intend to post several times in the future relating some of the information contained in the Techbook in general, and Mason’s article, in particular. This is the first of what hopefully will be a series.
The Eagle Ford in South Texas shares the spotlight with the Bakken in North Dakota as the shale plays responsible for the current energy renaissance in the U.S. Unofficially, each is currently producing about 1 million barrels of oil per day (bopd). Both have been major factors in the more than 50% increase in domestic oil production over the last four years to 7.7 million bopd.
The evolution of the Eagle Ford from discovery in 2009 to harvest phase in 2014 is a study in the triumph of technology and ingenuity in the face of organizational and engineering challenges. Extraordinary gains have been made in reducing drilling time and well costs through the use of state of the art rigs, and a new generation of downhole tools. Learning curves and use of drilling pads have also contributed to the current success in the Eagle Ford.
Operators are now seeking to bring the same efficiency gains from drilling to completion practices. Techniques being evaluated include tighter spacing of lateral legs of horizontal wells, zipper fracs (more tightly spaced frac intervals), and clustering frac zones in reservoir sweet spots; all with the purpose of increasing recoveries per well cost effectively. Other new concepts being tried include stacked laterals, both within the Eagle Ford, as well as other over/underlying formations in the field, such as the Austin Chalk, the Buda Lime and the Pearsall. The jury is still out, but experiments with these practices, as well as flow rates, sand volumes, and perforation spacing, appear to be paying off.