LAM IN ARIA—A NEW TIMOR SEA DISCOVERY

Abstract

The Laminaria-1 discovery in the southeast of AC/P8 is a major new Timor Sea oil accumulation. The discovery well, drilled in October 1994, encountered a gross oil column of 102 m in deltaic to jiearshore marine sediments of the Callovian-Oxfordian Laminaria Formation. On production test, a maximum flow rate of 7,507 BOPD was recorded through a 5/8 in. choke. The oil is a light (59° API), undersaturated oil with a GOR of 175 SCF/STB. Laminaria-1 was the first well drilled by the AC/P8 Joint Venture since resumption of exploration following resolution of the international boundary between Australia and Indonesia.

The Laminaria Prospect, originally identified prior to the boundary dispute, was detailed by seismic surveys in 1992 and 1993. The prospect was selected as the best of several structural targets, comprising a large complex horst block produced by major east-west faults, discernible on the 2D seismic lines at Aptian (KA) level. The prospect was expected to have Upper to Middle Jurassic Flamingo and Plover sandstone reservoirs, sealed by the Flamingo Group Shales,with hydrocarbons sourced from the same shales in adjacent synclines.

Since the discovery, a comprehensive appraisal campaign has been undertaken to delineate the accumulation, including the acquisition of a large 3D seismic survey over almost the entire AC/P8 permit, and the drilling of a further two wells and a sidetrack. The Laminaria horst is now interpreted to comprise a series of tilted fault-blocks, orientated ENE to WSW and dipping to the southeast.