Apco Oil & Gas International Inc., Tulsa, drilled two oil discoveries in Tordillo (Sierras Blancas) tight sandstones under a farmout from Roch SA and Madalena Ventures Inc. to increase to 45% its interest in the Coiron Amargo exploration permit in Argentina’s Neuquen basin.
Apco earned a 22.5% interest in the permit with two discoveries in 2010 (OGJ Online, Dec. 10, 2010).
The CAN x-4 well has been put on production from Tordillo. The CAS x-1 well, in the southern part of the 100,000-acre permit, also tested oil from the Vaca Muerta shale and will remain on test to determine its ability to sustain oil flow without stimulation (OGJ Online, July 19, 2011).
Depending on results of short-term tests, Apco will either frac the Vaca Muerta or place the Tordillo on production.
Apco and partners will further explore the Tordillo and Vaca Muerta by drilling and possibly reentering wells. They will decide by November, when the current exploration period expires, how much of the area to convert to an exploitation concession and how much, if any, to relinquish.
Coiron Amargo is adjacent to Apco’s core properties of Entre Lomas, Bajada del Palo, Charco del Palenque, and Agua Amarga. The southern part of Coiron Amargo is in the deepest part of the basin near the Loma de la Lata concession.