Colombia Probes Increase of Tremors Near Biggest Oilfield

Colombian authorities are working with Pacific Rubiales Energy Corp. to investigate an increase in seismic activity in the nation’s biggest oil-producing area.

The Colombian Geological Service, or SGC, is looking into possible causes of a rise in the number of tremors in eastern Meta province, where the country’s second-biggest oil company has its main operations, SGC geologist Marta Lucia Calvache said by telephone yesterday.

Opposition Senator Jorge Enrique Robledo and an oil workers’ union are blaming Pacific Rubiales’s Synchronized Thermal Additional Recovery, or STAR, technology, for the increase, an allegation the company says is unfounded. STAR is designed to increase flows by igniting oil in the well.

“The hypothesis is that the high temperatures and gases that are developing below are fracturing the rock,” Robledo, who plans to raise the issue during a congressional debate next week, said in an April 14 interview in Bogota.

The municipality of Puerto Gaitan, in the grassland and cattle-ranching region to the east of the Andes mountains, has historically been geologically stable, Calvache said. The SGC has recorded more than 250 tremors in the last year in the area, where Pacific and other oil producers have operations, compared with 10 tremors from 1993 to 2011.

Seismic Monitoring

Pacific said it set up a seismic monitoring system in the area last year to acquire more information on the tremors, a move it said was in response to a request from the local community. The company says there is no evidence that tremors are related to its operation and that STAR is safe.

“The information we have at the moment isn’t scientifically conclusive on the origin of the tremors,” the company said in reply to e-mailed questions. “In any case, movements in the earth don’t have any relation whatever to the application of STAR technololgy”.

Residents held demonstrations in March and April near the entrance to the Rubiales field, said Rodolfo Vecino, an official at the USO oil union, which represents some of Pacific’s workers. The tremors are damaging homes and the community is worried that STAR could also pollute water sources, according to Vecino.

“The community is protesting against Pacific because of the problems STAR is causing,” Vecino said in an April 16 interview. “Now there are tremors every day.”

The Ministry of Mines and Energy referred questions to the National Hydrocarbons Agency, which didn’t return a call requesting comment. Colombian state-owned oil producer Ecopetrol SA, a partner of Pacific’s in the area, declined to comment on the rise in tremors when contacted by e-mail.

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