Barossa offshore development
Barossa is a gas and condensate field found in offshore Australia, within the Bonaparte Basin of Timor Sea, which is approximately 300km north of Darwin in the Northern Territory. It lies in a water depth of between 130m and 350m and plans are underway to develop it together with the adjacent Caldita field.
The project is owned by a group of companies with different shares. The largest stakeholders are SK E&S Australia and ConocoPhillips Australia Exploration which have 37.5pct share each, followed by Santos Offshore with 25pct. Upon completion, the multi-billion dollar investment would help meet future international demand for natural gas, as well as contribute significant income and job opportunities. Locals will benefit from 100s of jobs that will be available in basic, middle and tertiary levels.
Barossa field was first discovered in Nov 2006 at a water depth of 320m, thereafter drilling of the Barossa-1 well commenced to a depth of 4,310 metres. Two drill stem tests were also done on the well, confirming the presence of natural gas. One test flowed at a rate of 30.1ft cubic per day, while the second one flowed at a speed of 0.8 million ft. cubic per day.
Preliminary appraisals were further conducted for the well which was found to contain as much as 16pct CO2 content, which was to be removed in the gas processing phase. The appraisal also covered various other stages of the project from phased-development drilling program to installation, fibre optic cable, the pipelines, pre-commissioning and future launch of the FPSO facility, as well as operations phase.
ConocoPhillips Barossa Project
So far, the Barossa field has been appraised by 5 wells. The first three wells which are Barossa-2, 3 and 4 were part of an earlier three-well appraisal programme completed in 2015. In particular, Barossa-2 hit 88m of net pay in the Plover, Upper Elang and Lower Elang reservoirs. On the other hand, Barossa-3 encountered 104 metres of net pay whereas Barossa-4 further confirmed the field’s potential.
Additionally, a second appraisal programme involving two wells which are Barossa-5 and Barossa-6 was successfully done in June 2017. The latter struck natural gas and condensate in the Elang oil reservoir found at depths of between 4,103m and 4,144m.
Experts estimate that Barossa will produce around 3.7 million tones of liquid natural gas (LNG) per year, together with 1.5 million bbl/year of organic condensate. The gas will provide a new source of fuel to the already existing Darwin LNG plant, subject to conducive commercial arrangements being set up.
Barossa’s development concept includes a solidly anchored floating production, storage and off-loading facility (FPSO). Including a subsea production system, and secondary in-field subsea systems in the field operated in retention lease NT/RL5.
The FPSO will serve to separate gas and condensate channeled from the field. Once collected, condensate will be exported directly through offtake tankers, whereas the dry gas shall be transported through subsea export pipeline for final processing on land.
There are also proposals that Barossa would replace the existing gas supply from Bayu-Undan, considering that the latter is expected to undergo total depletion by 2022. The subsea gas line will connect to Bayu-Undan facility which supplies the ConocoPhillips LNG plant, found at Wickham Point next to Darwin.
Being the project’s primary operator, ConocoPhillips has already submitted a development proposal to National Off-shore Petroleum Safety and Environment Management Authority (NOPSEMA) for consideration. The proposal is currently undergoing review by NOPSEMA.
While the new gas pipeline hasn’t yet been decided upon, a corridor has already been identified for purposes of early development of the offshore project proposal (OPP). This will enable flexibility for installation of the line once additional environmental and engineering investigations have been done.
Furthermore, the development concept has allowed for prospective future staged development of the much smaller Caldita field towards the south, which is in retention lease NT/RL6.
Pre-front end site engineering and design work (Pre-FEED) has also commenced, plus it will be followed by a FEED research in 2018. Barossa offshore development project is expected to have a lifespan of 20yrs and plans are already underway to make it fully operational by 2023.
ConocoPhillips’s Offshore Project Proposal (OPP) has been created in accordance with Australia’s environmental assessment process, which focuses on a new safe petroleum project in the Commonwealth waters. The final decision for investment on the project would be made in 2019. Firstly a very big thank you to ConocoPhillips for the image and information. If you would like to visit ConocoPhillips AU direct please go here >> http://www.conocophillips.com.au