Carnarvon Energy to spud well offshore Timor-Leste

Dec. 22, 2021

Carnarvon Energy Ltd. will spud the Buffalo-10 well in the TL-SO-T 19-14 production sharing contract, offshore Timor-Leste. The well is in Bonaparte basin and will be drilled by the JU-107 jack up drilling rig in about 30 m of water. The well will spud later this week and estimated time to drill and complete the well is around 35 days.

The well will test for commercial quantities of hydrocarbons that could ultimately result in redevelopment of the field. Reprocessed 3D seismic data using modern full waveform inversion technology supports interpretation of a significant attic oil accumulation remaining after the field’s original development.

The base case well design will be to drill a 36-in. x 26-in. hole and set 30-in. x 20-in. conductor at around 120 m. From there a 17 ½-in. hole will be drilled and set with 13 ⅜-in. surface casing at around 800 m. A 12 ¼-in. hole will be drilled to 2,800 m and set with 9 ⅝-in. intermediate casing. The reservoir will be drilled with an 8 ½-in. bit and set with 7-in. production liner to about 3,500 m. If successful, the well will be suspended with the cemented unperforated liner in place to be re-entered and completed for production at a future date.

The extent of the attic accumulation will be tested when the well is drilling through Elang reservoir in the 8 ½-in. hole section, where it is expected to penetrate both the existing oil column and assess extent of the attic column.

Reservoir modelling used updated structural interpretation of the field based on the recent reprocessed seismic data. The model was calibrated to historical production rates and water-cut evolution (governed by strong aquifer drive) observed during the original production period.

Carnarvon estimates Buffalo field 2C contingent resources at about 31.1 million bbl, with 15.3 million bbl low estimate and 47.8 million bbl high estimate. Ascertaining the volume of oil remaining will require an assessment of both the height of the attic as well as reservoir and fluid properties. This information is expected to be acquired during the drilling and will be assessed once drilling operations have finished. With estimated minimum economic field size significantly lower than the mid case estimate, there is a strong likelihood the Buffalo-10 well will confirm an economic project, the company said.

Carnarvon is operator at TL-SO-T 19-14 (50%) with partner Advanced Energy PLC (50%).