Carnarvon Updates Drilling Ops at L20/50

Carnarvon Petroleum, as operator of the L20/50 permit advised that following improved weather conditions, construction of road works and well sites is now underway for the drilling of up to three wells in the permit.

Drilling program

The objective of this first drilling program of up to three wells is to establish the presence of a potentially commercial petroleum system in this sub-basin of the Phitsanulok Basin. If the results of drilling are sufficiently encouraging, this will be followed up with a targeted 3D seismic program later in 2011 to better define prospects for further drilling.

The environmental impact assessment for the three prospect locations chosen by the Joint Venture has been approved by the Thai government authority. Furthermore, the joint venture has now agreed to drill two firm wells on the Tapao Kaew and Krai Thong prospects and one contingent well on the Chalawan prospect in the current drilling program. Drilling is targeted to commence mid January 2011 dependent on weather conditions and time for site construction. Each well will take approximately two to three weeks to drill and evaluate.


Whilst the drilling of these prospects is highly exploratory, due to the paucity of previous exploration drilling information and broad
2D seismic grid on which the prospect interpretation is based, mapped prospect sizes are substantial ranging from a gross midcase
recoverable oil volume estimate, if successful, of 21 mmbbls for Tapao Kaew, 37 mmbbls for Krai Thong and 32 mmbbls for Chalawan.

The three wells will evaluate three different prospect styles. The first well planned to be at Tapao Kaew will evaluate a potential stacked reservoir, hanging wall anticlinal closure on the western edge of the basin, immediately adjacent to the interpreted hydrocarbon kitchen. The well will be drilled to a planned total depth of 1,715 meters.

The second well at Krai Thong will evaluate interpreted four way dip closures with potential stacked and mounded alluvial fan deltas further to the south of the basin. The planned total depth of the well is 1450 meters.

If these two wells provide sufficient encouragement, a third well may be drilled at Chalawan. This structure comprises a series of tilted fault closures on the eastern edge of the basin. This is planned to be a shallow well to a depth of 950 meters.

L20/50 Concession Permit Holders

  • Carnarvon Petroleum Ltd (Operator) 50%
  • Sun Oil NL 50%