Southwestern Energy Co. of Houston pioneered the Fayetteville shale play on the Arkansas side of the Arkoma Basin.
Innovative techniques helped the company increase Fayetteville gas production from 20 million cubic feet per day in May to 50 million at the beginning of August this year.
The company invested more than $160 million in the Fayetteville during the first half of 2006, including more than $40 million for drilling rigs to be used in the play.
AAPG member John Thaeler, senior vice president of Southwestern Energy operating company SEECO Inc., described three areas of innovation:
♦ Well-bore construction and drilling.
“We purchased 11 drilling rigs, of which eight have been delivered, specifically designed for drilling shale-play depths in the Fayetteville shale,” which range from 1,500 to 6,500 feet deep in the company’s area of interest, he said.
In addition, the company operates two shallow rigs in the Fayetteville.
Those rigs drill the shallower, vertical section of the holes, then the deep rigs later drill horizontal wells with laterals up to 4,000 feet, Thaeler said.
♦ Reservoir characterization.
“We’ve taken a great deal of effort to conduct a full core acquisition and analysis program throughout the area to better understand depositional models and facies,” Thaeler noted.
Also, the company devotes a technical team to studying the Fayetteville shale, including geology, geophysics, reservoir engineering, production engineering and drilling engineering.
“They are tasked with acquiring and then analyzing the data as soon as it comes in, and integrating that information into our operational plans,” Thaeler said.
“This allows us to continuously innovate while we stay focused on maintaining an active drilling and operations program,” he added.
Improving recovery efficiencies.
“We have evolved the fluids we’re using, and we have gone completely to horizontal drilling now. We’ve moved from nitrogen-foam fracs to slickwater and cross-linked gel stimulation,” Thaeler said.
The company also finds that acid-soluble cements can reduce treatment pressure requirements, and it continues to study new applications in completion technology, he added.
Through July, the company had completed 105 wells in the Fayetteville shale, 54 of them horizontal. The cost of a completed slickwater horizontal well in the play averaged about $2.1 million.
Southwestern Energy continues to expand its Fayetteville play area, moving east into Arkansas’ White County and also testing deeper Moorefield and Chattanooga shales.