HDD Helps Producer Tap Gas Reserves Under DFW Airport

The Barnett Shale is among the nation’s fastest growing natural gas fields. The formation encompasses more than 5,000 square miles and stretches from Dallas to Fort Worth, TX. With estimated natural gas resources in excess of 30 Tcf, the potential contribution of this formation as an energy source is immense.

Coined an “unconventional” deposit by geologists, the shale that comprises this vast natural gas reservoir is very hard-– making it difficult to produce economically in commercial quantities. As if the geometric composition weren’t challenging enough, development has also been hampered by the fact that major portions of the field lay beneath the most densely populated areas of North Texas - most notably, the Dallas-Fort Worth metroplex. But recent technological improvements in hydraulic fracturing and horizontal directional drilling (HDD) techniques have since changed all that.

Among the largest lease offerings located within the Barnett Shale was an 18,000-acre tract encompassing Dallas-Fort Worth International Airport. The airport authority awarded the lease and drilling rights to Chesapeake Energy, one of the nation’s largest producers of natural gas. Chesapeake selected Dallas-based Driver Pipeline to tackle the complicated task of installing an intricate pipeline system to transport the natural gas produced from beneath the third-busiest airport in the world. Driver Pipeline was well-positioned to complete the pipeline work, having more than 800 employees and a fleet of equipment that numbers over 300.

The project involves installing a 24-inch pipeline around the parameter of the airport and a gathering line consisting of 8-24-inch lateral lines to channel the extracted natural gas from an estimated 100 wells. The gathering line transports the gas to a compressor station located on the north side of the airport which functions to pressurize the gas before moving on to another pipeline for distribution and delivery to market. There will also be a 10-inch line to take saltwater back to injection wells and both 10- and 12-inch lines to carry fresh water to the wells.

The entire saltwater gathering line is composed of 50-foot polyethylene links that were fused together using a poly fusion machine and installed using advanced HDD techniques. The various bores range from 15-65 feet in depth, depending on what Driver’s crews encounter underground. When complete, the gathering line plus additional feeder lines will total over 100 miles in length.

“As you can imagine, there are numerous logistical challenges involved with installing such an intricate pipeline system under one of the world’s busiest airports,” said Scott Driver, vice president of operations for Driver Pipeline. “The only way this project could be completed is by using HDD since what lies on the surface is a network of runways, terminals and cargo facilities. And that just describes the surface. What lies underneath presents another set of challenges.”

Geological surveys completed prior to beginning the installation showed that the ground conditions and composition of the subsurface soils varied a great deal. According to Driver, the project started out in black gumbo-like dirt and moved to red clay with sandstone layers. Opposite the starting point, Driver’s crews encountered sandstone with rock ledges along with just basic sand.