By OGJ editors
HOUSTON, Apr. 6 -- Amerisur Resources PLC said Platanillo field in Colombia’s Putumayo basin averaged 452 b/d of oil in the last 9 months of 2010 compared with 180 b/d or less in 2009 even though limited zones are in production.
Platanillo lies east of Orito field, the basin’s largest, and just north of Victor Hugo Ruales field in Ecuador, which has 120 million bbl of recoverable oil.
Calmena Energy Services is expected to mobilize Rig 836, which has been drilling wells as deep as 10,000 ft for Petroleos Mexicanos in Mexico, to Colombia in April 2011 to work for Amerisur at Platanillo.
The company worked to “define the full field potential via 3D3C seismic and have strengthened our operating base in this challenging and in some ways frontier area.”
Amerisur acquired the 705 ha of acreage in Colombia between Platanillo and VHR field in Ecuador. The most important and challenging work program was the design, acquisition, processing, and interpretation of the 125 sq km 3D3C seismic survey over the entire block from the national border in the south to the northern contractual limit. Acquisition ended on Dec. 23, 2010.
The survey used the latest digital technology and sensors that detect three orthogonal wave components. Usually only the vertical component is recorded, which is generally dominated by the compressional or “P” wave.
The benefit of recording additional components comes from capturing aspects of the shear or “S” wave. This wave can be used to indicate rock and rock fluid characteristics in the zones of interest. Multicomponent processing is still at an early stage globally, but Amerisur believes the data will be most useful. Processing to date has utilized the vertical component, and has been performed in Bogota and Buenos Aires.
The data have been interpreted and a new structural map of the southern half of the block has been created.
The mapping has resolved a previous ambiguity regarding the presence and degree of throw of the bounding fault at some points along the structure, with confirmation of continuity towards the north, and importantly towards the south, into the extended commercial area. In addition, the structure observed to the south of the Alea-1R and Platanillo-2 wells is far more developed than previously supposed.
The 3D3C structure map and petrophysical data were analyzed in a Monte Carlo simulation and indicated the following management-estimated prospective resources for Platanillo field: A 90% probability of 45 million bbl of oil, a 50% chance of 69 million bbl, and a 10% chance of 95 million bbl.
The operational plan was modified to take account of the new high potential in the southern section, and the drilling program has been redesigned. This has necessitated further environmental licensing and will require road construction in coming months. It is envisaged that the first new wells will be located in the southern sector, followed by wells to the north in the area previously called “Platanillo-3.”
The company expects to begin a six-well drilling program before midyear 2011. The objective is to prove up 35 million bbl of proved and probable reserves and end the year with 5,000 b/d of production.
Colombia: Platanillo output up, seismic in hand
By OGJ editors