The US Department of Energy will help fund a project to test a coal-based filtering material that could slash the cost of waste water disposal from stripper gas wells. The test will be at the Rosebud SynCoal demonstration plant near Colstrip, Mont., built under DOE's Clean Coal Technology Program.
DOE said the plant's upgraded coal product, originally intended as a high-quality fuel for power plants, may also be a low-cost filter material for oil and gas well waste water.
The department will award $132,000 to Western SynCoal LLC of Billings, Mont., which will spend another $28,000 of its money on the project.
DOE said SynCoal is a high-quality, low-moisture coal material made by heating and physically cleaning low-rank sub-bituminous coal.
"Originally intended as a low-sulfur fuel for power plants, the material has characteristics that researchers believe will make it ideal for filtering contaminated waste water," said the department. "Its affinity for capturing hydrocarbon and other impurities makes it similar to activated carbon, but it is much less expensive.
"The product is so economical that, if successful, it could reduce water disposal costs from low-volume gas wells by 70%. Such a dramatic cost reduction would prolong the economical lifetimes of thousands of stripper gas wells, allowing gas to continue flowing that might otherwise be shut in."
DOE said water produced by the SynCoal filtering process is clean enough for agricultural use.
There are 191,000 gas stripper wells in the Lower 48 states producing an average of 16 Mcfd, about 8% of US gas production.
Waste water disposal is a major economic factor for gas strippers, said DOE. "Gas producers often must truck the waste water to disposal wells that can be several miles from the production site. Excluding trucking costs, waste water disposal can cost as much as $2/bbl."
