Crews worked through heavy snow last weekend in starting operations to remove a section of the pipeline from the Yellowstone River near Billings, Mont.
Crews working for Exxon Mobil set up a coffer dam around the pipeline and deployed mechanical "pigs" to clean out the damaged section.
An Exxon Mobile spokeswoman told the Billings Gazette it would take several weeks to get the pipeline out of the ground. The section is to be sent to an independent facility for analysis.
Around 1,200 barrels of oil spilled from Exxon Mobil's Silvertip pipeline into the Yellowstone River near Billings in early July. Flooding slowed cleanup efforts and teams were sent in to remove debris soaked with oil after water levels dropped.
The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration in September approved of the energy company's return-to-service plan, which allows Exxon to restart operations on Silvertip.
The PHMSA added it was still determining whether Exxon broke safety regulations during the days leading up to the July 1 failure on the pipeline.