Shale gas reserve at Red Dog zinc mine estimated at 2 trillion cubic feet; mineral coring rig working area

Kristen Nelson, PNA editor-in-chief

A mineral coring rig has been working in the vicinity of the Red Dog zinc mine in northwestern Alaska, exploring for extensions of the known zinc ore body.

In the process, G.J. Koperna Jr., of Advance Resources International said May 22 at the AAPG Pacific Section Convention/SPE Western Regional Meeting in Anchorage, drillers and geologists “noticed the core is popping and snapping and cracking — and that’s audible gas.”

Mine operator Teck Cominco hopes to use local natural gas to reduce energy costs and replace the 18 million barrels of diesel brought in each year to power the mine.

From 1998 to 2000, in conjunction with mineral exploration, Teck Cominco also explored for gas, Koperna said and under a U.S. Department of Energy contract awarded to a partnership of NANA Development Corp., Teck Cominco Alaska and Advance Resources International, a core sampling program and logging was done. One goal, Koperna said, is technology transfer: to show results and how they were obtained so that remote rural villages might be able to study shallow gas.

The resource at Red Dog is shale gas from the Kuna formation. Coring was done with an LF-70 rig. Slim-hole logging was done by a mineral logging company out of South Africa. It was “cheaper for them to come up and do the work than to have a traditional oil field provider do it… they specialize in slim-hole mineral logging…,” Koperna said.

In 2001, a geologist was brought in who had worked with shales for several decades in the Appalachian basin. He looked at the wells and recommended completions and tests.

Over a four-year program about 200 gas content analyses were collected and eight whole geophysical logging sets were run.

The next step is to get the first production test. It would take 60 billion cubic feet over 20 years to replace the diesel, and the current estimate is that 40 to 60 wells would be required.

If slim-hole production methodologies can be designed for implementation in rural areas the cost savings would be phenomenal, Koperna said.

“It you can do it, it would be a boon to rural economies.”