Amerisur Resources confirms discovery at Mariposa-1 well in Colombia


Oil and gas producer and explorer Amerisur Resources has confirmed a discovery with the exploration well Mariposa-1 in the CPO-5 contract area in Colombia.

The well was successfully drilled in May this year as part of an exploration and production (E&P) contract executed by the company and its partner ONGC Videsh with the Agencia Nacional de Hidrocarburos (ANH).

The well test demonstrated a natural controlled flow rate of around 4,601 barrels of oil per day of 40.8° API oil with a water cut of 0.35% and 348psi flowing wellhead pressure over a 40in / 64in choke.

Amerisur Resources CEO John Wardle said: "We continue to be encouraged by the results of Mariposa-1 and the future exciting potential within CPO-5.

“Preparations for further drilling have commenced and we look forward to updating shareholders on our progress."

"Preparations for further drilling have commenced and we look forward to updating shareholders on our progress."

After drilling to a depth of 11,556ft, a 7in production liner was run and cemented in the well.

In addition, an interval of 12ft at the top of the 120ft of net pay logged in the L3 sandstone was penetrated in an attempt to conduct a short-term test with a drill-stem-test temporary string. 

The test featured natural flow over different choke sizes, in addition to closed-in pressure build up periods to determine reservoir parameters.

The well has been closed following interpretation of the test data.

ONGC Videsh is the well's operator and will present the evaluation plan, which provides for a long-term test on Mariposa to ANH.

Upon approval of the plan, Amerisur is expected to bring the well online in the second half of this year.

Amerisur owns a 30% working interest in the contract, while the remaining 70% interest is held by ONGC Videsh.