|Top five causes for spills in Colorado,|
New Mexico and Texas, the states
that report spill sources. Records for
New Mexico and Texas go back to
2009, Colorado data to April 2014.
"There are different terms for flow lines, but generally they refer to narrow pipelines that carry oil, gas or wastewater—often all three—from scattered wells to tanks or other equipment within the same lease," Soraghan writes. "Other lines, like gathering lines and transmission pipelines, are larger. They lead to processing facilities and away from production sites."
|Flow lines (Colorado Oil and Gas |
Conservation Commission photo)
"Flow lines are more common with conventional oil and gas development, in which vertical wells are scattered across vast acreage. In modern shale development, horizontal well bores spread out underground," Soraghan reports. "But wellheads are concentrated in one area at the surface, so there's less need for long flow lines. They usually leak oil or 'produced water'—a salty, toxic mix of fluids—along with natural gas. The gas leaked from such lines often isn't reported."
Kerry Sublette, a spill cleanup expert and chemical engineering professor at the University of Tulsa, told Soraghan, "In a lot of these mature fields, they haven't been replaced in a long time. If nobody's looking over your shoulder, you're not as likely to replace it." Soraghan notes that "most states don't require that operators dig up and remove the lines when they're done using them." Sublette told him, "They've got lines that they've got no idea where they go. They never remove them."