Drilling and Well Completion Technology

The Bayu-Undan development drilling campaign commenced May 17, 2002 and is expected to comprise up to 16 development wells plus 1 water injector well, with an anticipated duration of approximately 750 days. Batch drilling will be employed on the first three casing strings on the first platform, BU-WP1. A shore base in Darwin to support the drilling campaign has been opened. All materials will be consolidated and mobilized through this base.

The preliminary development well design is based on the experience gained from more than twenty offset exploration and appraisal wells drilled in the Bayu-Undan area. The preliminary completion design is based on a review of the key well objectives to maximize flow performance and minimize well intervention and workover requirements throughout the twenty-five year design life of the wells.

The Chiles Discovery, a conventional jack-up rig operating in cantilever mode, will carry out all drilling. The jack-up rig will be located adjacent to the BU-DPP and BU-WP1 jacket structures and cantilevered over the platform well bays. The BU-WP1 (14 slots) and the BU-DPP (16 slots) will be located in approximately 78 meters water depth. All development wells will be directionally drilled from the platform drilling centers to their respective bottom hole reservoir target locations. The Phase I drilling program is 6 wells, all producers, drilled at the WP1 location.


The operation will then move to the DPP location where a further 10 wells (5 producers and 5 gas injectors) are planned. In addition there will be a requirement to drill at least one shallow water injector at DPP. The well will be designed to allow 2 shallow water injectors to be drilled from the same slot (shared conductor).
The first well will be drilled as the primary produced water disposal method. A second well would only be drilled if required at the end of the drilling program.

The majority of the wells lie within a 4500m step out from the planned drilling center locations. There are three wells that exceed this step out, one of which is at 5800m, which equates to a measured depth of 6700m. Well deviations are in the range of 32° to 68°. One primary and one backup well on each of the drilling facilities will be configured to allow cuttings injection down the 20” by 13-3/8” annuli.


Contracting and procurement activity for services and materials to be provided in support of the drilling program is completed. The focus has shifted from contracting to execution and key performance indicators will be monitored throughout the drilling program.

Please note that all references to Phillips or Phillips Petroleum on this page refer to Phillips Petroleum (91-12) Pty Ltd as Unit Operator for the Bayu-Undan development, except as specifically mentioned otherwise.

Copyright 2001 Phillips Petroleum (91-12) Pty Ltd. All rights reserved.
Updated 08/06/04