A Successful Unconventional Play: Using the North American Eagle Ford as an Example for Developing Plays in China

Thomas D. Bowman
ZaZa Energy Corporation, Houston, TX, USA

The Gulf Coast of Texas has been producing oil and gas traversing the last 100 years and the regions various rock formations continue to attract the attention of oil and gas companies today. Currently, the region is known for the soaring Eagle Ford Shale formation that is quickly becoming one of the largest oil and gas fields in the world. The Eagle Ford shale field is currently ranked as number eight of the largest oil fields.

From record drilling levels, to wells initially producing over 7,513 barrels of oil and 6.8 mmcf of natural gas per day (8,600 boe/d) from the Eagle Ford., the play is redefining and focusing the petroleum industry to South Texas and this production is bringing brand-new wealth to the region and the state. An estimated $30 billion dollars is budgeted to developing the play in 2013 (up from more than $25 billion dollars in 2011) providing an enormous economic impact to South Texas. It is estimated that over 50,000 jobs are supported in the 20-plus county area where the bulk of exploration and development drilling is taking place. Combine these with the new jobs created in surrounding counties and the definition of a modern oil boom is taking shape.

Current oil production in the play (July 2013) has exceeded 564,000 barrels of oil and 2.342 billion cubic feet of gas and 121,382 barrels of condensate production per day (1,075,715 BOEpd). Petrohawk drilled the first of the recent Eagle Ford wells in 2008, but early Eagle Ford production can be traced back to wells at least as early as 1955. Some of these early vertical wells made little more than uneconomic shows, but the theory of producibility in the Eagle Ford was cast. Petrohawk drilled the “discovery” well for the Eagle Ford in La Salle County over 50 years later. This well, the STS #1H, spud in July 2008 (completed in October 2008) produced 8.9 million cubic feet equivalent (128 barrels of 61.2° condensate and 8.16 million cubic feet of gas per day) from a 3,200-foot lateral multi-staged stimulated horizontal. This well set the Eagle Ford play in motion to becoming the household name it is today.

The Eagle Ford Shale furthers its importance as a hydrocarbon producing formation due to its capability of producing both gas and more oil than other traditional shale plays. The wells in the deeper part of the play deliver a dry gas to condensate mix, but moving northeastward and updip along the trend tend to produce predominately liquids.

The Eagle Ford Group was locally named from along the outcrop six miles west of Dallas in the community of Eagle Ford, Texas. The time-equivalent Upper Cretaceous formations can be seen in outcrop from West Texas along the Rio Grande River, east across the southern Gulf Coast states and north along the eastern United States. This trend covers a length of over 1,500 miles and reaches as far north as New Jersey. This section is referred to as the Eagle Ford shale in the Southwest Texas counties and is regionally referred to by many names such as the Boquilles, Eagle Ford, Woodbine, Eaglebine, Maness, Tuscaloosa, and Raritan formations. These formations, regardless of the name, are typically dark, organic-rich, brittle, fractured, fossiliferous, pyretic, siliceous, and calcareous dark-grey to black shale deposited across the Cenomanian-Turonian Upper Cretaceous stages. The Cenomanian-Turonian boundary event, also known as the Cenomanian-Turonian extinction event, was the later of two anoxic extinction events in the Upper Cretaceous period providing the geological landscape, deposition, and perseveration of organic rich sediments across the planet. In its full extent, this shale play could be the largest unconventional resource play in the world. Currently spanning several North American states, the time equivalent Upper Cretaceous formations can provide the potential for analogues oil and gas resources across the planet.

AAPG Datapages/Search and Discovery Article #90180©AAPG/SEPM/China University of Petroleum/PetroChina-RIPED Joint Research Conference, Beijing, China, September 23-28, 2013