BOGOTÁ — In the past three years, Colombia has seen a depletion of some 500 million barrels of crude from its national oil reserves, a bona fide threat to its energy self-sufficiency.

To counter this, Colombian energy leaders have begun to consider a turn to so-called "fracking," or hydraulic fracturing, the technique used to extract crude oil from shale stone. The national oil form Ecopetrol, which produces 70% of the country's oil, announced early this year a 14% drop in its oil reserves thanks to low prices — a disincentive to exploration — and may even have lost up to 20% of its reserves because of this.

This means the country is down to some 1.7 billion barrels, which would meet its needs only until 2023.

The principle of caution must prevail.

Julio César Vera, president of the Colombian Association of Oil Engineers (ACIPET), says exploration and seismology are at very low levels, adding that "as production falls, reserves also fall."

The country's main potential for fracking exploitation is the Magdalena Medio, a strip running up central Colombia through the departments of Santander, Cesar and northern Boyacá. Tapping into shale "would allow us to go from 1.6 billion barrels to more than 7 billion," Vera says. ACIPET puts fracking's production potential at between five and eight billion barrels of crude oil annually, and possibly 60 trillion cubic feet of gas. The country's current gas reserves are below seven trillion cubic feet.

But the water and environmental protection group Cordatec is already denouncing the environmental harm that the new oil exploration could wreak. "We are not prepared for fracking," says the group memeber, Óscar Vanegas, a lecturer at the Santander Industrial University. "We haven't done the necessary in-depth scientific research to be sure, and the principle of caution must prevail," he says.

The National Environmental Licenses Authority (ANLA), part of the Environment Ministry, says ExxonMobil is the only firm to have applied so far for a fracking license in the district of Puerto Wilches. "We have an application from ExxonMobil for the Magdalena Medio Valley and have yet to decide," said a spokesman.

Juan Carlos Rodríguez, ACIPET's executive director, says the extraction technique of "hydraulic stimulation" has long been present in Colombia and offers a gateway into the shale gas exploration. Fracking's environmental impact, he said, could be limited with "current technology."

ACIPET, representing Colombia's oil industry engineers, has announced it would take legal action to defend the "right" to pursue shale exploitation in the face of public initiatives currently underway to impede it in the central Colombian district of Cumaral. Says ACIPET's president Vera: "The possibility of losing 40 years of oil self-sufficiency is of great concern."