The insurgent group ELN was blamed for the attack, the Colombian news website Colombia Reports said Monday.
"Unfortunately insurgent groups operating in this sector ... detonated an explosive charge at one of the valves of the Cano Limon-Covenas [section of the pipeline]. At the time, crude was not being pumped so the spill was minimal. The explosion, more worrying, caused damage to three close-to-the-site houses," Mayor Jhon Jairo Alonso told Caracol Radio Sunday.
ELN declared its intent to financially injure multinational oil companies operating in Colombia last year.
Local political leaders have been the subjects of threats and intimidation, and Saturday Segundo Benjamin Morales, a councilor in the town of San Jose de Alban, was shot and killed in his home, Caracol Radio said.
Four other town councilors left town with their families after death threats, the National Federation of Councils said in a statement.
On Friday, 13 councilors and a community leader left the nearby town of El Tambo because of threats, Colombia Reports said.