Southwestern Wyoming’s Upper Green River Valley is home to the most extensive wetlands and riparian areas in the state, and its vast sagebrush prairies have long been a stronghold for sage grouse, antelope and mule deer. The Upper Green is also the site of the huge Jonah natural gas field.
Field stretches over 32,000 acres and yields 255 billion cubic feet
of natural gas each year. The impact of all that production on the
land, air and wildlife has been severe. But one company, EnCana Oil
and Gas, Inc., is trying something a little different to help
minimize its harm.
About 18 months ago, the Bureau of
Land Management allowed EnCana to start using wooden mats to
protect the landscape around its Jonah gas wells. “Imagine a
hardwood floor placed on top of an acre of prairie,” says
Randy Teeuwen, EnCana community relations adviser. Measuring about
10 feet by 10 feet and weighing around 2,000 pounds, the mats
protect topsoil from drilling equipment and the treads of heavy
trucks, leaving the root systems of plants and grasses intact so
they can recover faster.
EnCana lays the interlocking
mats -- typically about 3,000 of them – directly over
vegetation on flat drilling sites instead of clearing bare earth
pads for wells. The mats provide a path from roads to gas wells, so
that vehicles need not come into direct contact with the soil. The
company leaves the mats in place for about 30 to 45 days, or until
it completes drilling, and then moves them to another drill site. A
plastic liner below the mats traps condensation and seems to
provide moisture to the vegetation underneath it, Teeuwen says,
helping the plants recover once the mats are removed.
“Once we remove the mats, we pretty much leave the area
alone,” Teeuwen says. Even when monitoring the wells, EnCana
doesn’t allow motorized vehicles to leave the roads in order
to drive to a site. Employees must park on roads and walk in,
though on rare occasions they can use an ATV.
environmental groups in the area remain skeptical about whether the
mats will make much of a difference. “It’s a great idea
to allow the soil horizons (layers) to remain,” says Linda
Baker of the Upper Green River Valley Coalition, a nonprofit group
that advocates for responsible drilling. But Baker worries that the
extensive drilling in the Jonah Field makes any reclamation moot.
And in the high, cold desert, restoring vegetation is difficult,
she says. “Every time I go out there, I don’t see
successful reclamation -- except the old, old stuff, and
that’s only because it’s been left alone for 30
years.” Even so, Baker would like to see the mats used more
extensively and by companies besides EnCana. In an area like Jonah,
which is relatively flat, she says, it seems more of these mats
could be successfully used.
At least one other energy
company in the area is using wooden drilling mats. BP lays them
around its wells in the Wamsutter Field, but doesn’t use them
in Jonah because its sites there are too steep, according to BP
spokeswoman Paula Barnett.
The reusable mats are more
expensive than traditional reclamation (which involves replacing
topsoil, reseeding and irrigating cleared land), says Teeuwen. The
12,000 mats EnCana now uses at Jonah cost the company over $10
million. (EnCana’s profits were almost $4 billion last year.)
Still, he adds, EnCana is looking to use the mats in other regions
-- wherever the topography can support them -- in order to soften
its environmental impacts.
The author is a High
Country News intern.