Page 284 - Annual Report 2020

FY2018 proved reserves Revisions
Production for FY2018 totalled 192 MMboe in sales, which was Overall, net revisions decreased proved reserves by 7 MMboe
a decrease of 16 MMboe from FY2017 (refer to section 6.3.2 for during FY2018. In our Australian operations, reductions of 21
more information). There was an additional 5 MMboe in non-sales MMboe occurred, primarily in the North West Shelf, due to revisions
production, primarily for fuel consumed in our Petroleum related to updated technical assessments. In the United States, net
operations. The combined sales and non-sales production totalled revisions increased reserves by approximately 4 MMboe. This was
198 MMboe. The natural decline of production in our Onshore a result of additions of 35 MMboe, primarily for strong performance
US fields and mature fields in other locations was the primary in the Atlantis field in the Offshore US Gulf of Mexico, and better
reason for the lower amount produced. performance in our Onshore US Eagle Ford and Permian assets.
As of 30 June 2018, our proved reserves totalled 1,400 MMboe These additions were partially offset by reductions of 33 MMboe,
mainly in our Onshore US fields as a result of lower planned drilling
and reflected a net increase of 62 MMboe and production of activity in light of our previously announced plan to exit our shale
198 MMboe from the 1,535 MMboe reported at FY2017. This increase operations and the effect of lower gas prices. In Other areas
was primarily the result of continued strong performance in our outside of Australia and the United States, revisions increased
Offshore US fields in the Gulf of Mexico and Offshore Trinidad reserves by 10 MMboe, primarily for strong performance in the
and Tobago, along with better performance and improved liquid Angostura Phase 3 project in Offshore Trinidad and Tobago.
product prices for our North American shale operations. These
increases were partially offset by reductions in the North West Of the overall decrease in proved reserves of 7 MMboe through
Shelf (Australia) and reduced gas prices received for production revisions, the impact of commodity prices using the required
from our Onshore US fields. Net additions to reserves resulted SEC price-basis represented a decrease of 4 MMboe while well
in a reserves replacement of 32 per cent overall, (Conventional: performance, interest changes and other revisions resulted in a net
25 per cent reserves replacement, Onshore US: 43 per cent decrease of 3 MMboe. Virtually all of the price-related decrease
reserves replacement). As of 30 June 2018, approximately occurred in our Onshore US fields where increases of 26 MMboe
65 per cent of our proved reserves were in conventional fields, occurred in the Eagle Ford and Permian fields as a result of higher
while about 35 per cent of our proved reserves were in liquids prices, but these additions were more than offset by
unconventional fields. 31 MMboe in reductions in Haynesville and Fayetteville due
Extensions and discoveries to lower gas prices.
Extensions and discoveries added 75 MMboe to proved reserves Purchases and sales
during FY2018. This was comprised of 69 MMboe of extensions The sale of Petroleum’s interests in the US Onshore Eagle Ford
related to planned drilling in new locations in our Onshore US field accounted for our reported sales of approximately 5 MMboe.
operations within the next five years and an additional 4 MMboe There were no purchases during FY2018.
in the Mad Dog field and 2 MMboe in the Shenzi field, both of These results are summarised in the following tables, which
which are in the US Gulf of Mexico. detail estimated oil, condensate, NGL and natural gas reserves
Improved recovery revisions at 30 June 2020, 30 June 2019, 30 June 2018, and 30 June 2017,
There were no improved recovery revisions during the year. with a reconciliation of the changes in each year.

282 BHP Annual Report 2020