BISMARCK — Crews extinguished fires on an oil well pad bordering Lake Sakakawea in McKenzie County late in the day on Saturday, Aug. 7, after the wells burned for more than two weeks.
The fires started July 22 in three oil wells on a site north of Keene, N.D., operated by the Texas-based company Petro-Hunt.
Lynn Helms, North Dakota's top oil industry regulator, attributed the outbreak to the failure of a blowout preventer, a crucial mechanical valve that stops the uncontrolled release of oil from a well.
Emergency responders shut down the first of the burning wells and extinguished its fire early last week. They worked for several more days to kill the remaining two ruptured wells, succeeding on Saturday evening. The fourth well on site never caught fire but was killed early on to avoid another blowout preventer failure.
Petro-Hunt spokeswoman Beth Babb confirmed on Monday morning that the fires had been extinguished over the weekend and said the company is working on a soil remediation plan while general surface cleanup continues.
Dangerous heat levels and volatile winds kept responders from controlling the situation sooner, leaving plumes of smoke visible from miles away in the first week the fires burned.
Responders used water from Lake Sakakawea to lower temperatures on the well pad, said Lucas Graf, McKenzie District Ranger for the U.S. Forest Service. They often had to wait long periods for weather and fire conditions to improve enough to approach the wells.
Crews extinguished the first fire last week by pumping heavy fluid down the well, overcoming the upward pressure of oil until they could install valve mechanisms to restabilize the well, Babb said.
A second well was controlled Saturday evening using similar methods, while the fire in a third well died down on its own, according to Babb.
Petro-Hunt brought in the Texas-based specialists Wild Well Control to help put out the fires. Babb said that company's work is complete now that the fires are out.
The precise cause of the fires and blowout preventer failure is under investigation by the North Dakota Industrial Commission, which regulates the petroleum industry in the state.
The Department of Environmental Quality has been monitoring the situation at the Petro-Hunt well site over the last two weeks and sent an inspector out to the scene on Monday to assess damages.
Petro-Hunt initially reported that 100 barrels of oil and 100 barrels of produced water spilled on the site when the fires broke out, but state environment officials said an accurate evaluation wouldn't be possible until after the fires were extinguished.
So far, the department believes that all oil and produced water spilled was contained to the well-pad. Despite initial concerns, the fires had no notable effect on air quality, department director Dave Glatt said Monday.
The fire burned on U.S. Forest Service land on a slope just above Lake Sakakawea, raising concerns during the outbreak that escaped oil and brine could spill into the water.
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