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 Unconventional 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 and sets as another example of successfully developing an unconventional oil and gas resource.
Analysis and completion techniques have been evolving since the Barnett shale becoming the first unconventional resource play considered for economic production. After taking a reported 19 years to perfect the analysis and techniques to complete the Barnett shale, it started a worldwide revolution of unconventional resource development. However, it quickly became evident after development began in new and emerging plays, such at the Bakken, Woodford, Haynesville, and Eagle Ford formations, each formation is individual and different. Each resource play may have similarities, but the completions require significant variations to allow economic extraction of oil and gas resources.
The Eagle Ford Shale is the latest successful unconventional resource play to gather the attention of the oil and gas industry. Development of the Eagle Ford formation, which began in 2008, and now the 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) and has 3,868 oil wells and 1,681 gas wells producing.
Initially the Eagle Ford formation was analyzed and completed using techniques perfected from previous unconventional resource plays, with remarkable initial results. As the number of wells and the experience has increased, the industry has perfected the analysis and completion techniques producing multi-fold increases in initial production rates and ultimate recoveries of oil and gas resources.
Analysis techniques, detailed core analysis, and petrophysical modeling have increased the understanding of the formations perfecting the placement of the horizontal wellbores and field practices such as multi-stage horizontal well pads combined with micro-seismic monitoring have supported more aggressive completion stimulations with combined results of increased recovery of oil and gas resources. Unlike previous unconventional plays, the Eagle Ford is a carbonate rich black shale deposited during the Upper Cretaceous and previous unconventional shale plays were largely silica rich formations. The increase in carbonate, originally thought to limit the uses of hydraulic-stimulation, has now, through more robust stimulation practices, is no longer a limiting factor in not only the Upper Cretaceous Eagle Ford, but now sets the example for new and emerging unconventional resource plays throughout the world.
AAPG Datapages/Search and Discovery Article #90180©AAPG/SEPM/China University of Petroleum/PetroChina-RIPED Joint Research Conference, Beijing, China, September 23-28, 2013