THE TALBOT OILFIELD, VULCAN SUB-BASIN, TIMOR SEA: A TRIASSIC OIL DISCOVERY

Abstract

Talbot-l, the discovery well for the Talbot Field, was the first well of a four well drilling program operated by SANTOS Limited in permit AC/P12 during 1989 and 1990. AC/PI 2 was gazetted for competitive bidding and awarded in February 1989. Following a seismic program involving acquisition of 2660 km of 2-D and 3360 km of 3-D data together with seismic reprocessing, a significant fault-dependent structural high was defined within the 3-D grid. Interpretation of this structure, subsequently named Talbot, revealed tectonic and stratigraphic similarities to the Challis Oilfield, 40 km to the northeast. Talbot-l was chosen as the first well of the commitment program and spudded in November 1989. The well flowed oil at an un- stabilised rate of 4981 BOPD on 7 December 1989, nine months after the permit was awarded.

The Talbot-l discovery and the Talbot-2 appraisal have confirmed a modest size oilfield located on a structural horst. The Triassic oil-bearing section is a layered sequence of texturally and mineralogically immature clastics and carbonates deposited in a nearshore marine environment. Because of pre-unconformity structural dip, faulting within the reservoir sequence, layering, and a small gas cap, the Talbot Oilfield will require detailed geological, geophysical and engineering studies to assess the likely production performance of the field. If a Talbot development can be demonstrated to be economic, a third well may be required. Production could commence 12 months from the decision to develop the field.