North Sea petroleum (oil+natural gas) production from 1970 to 2008 can be modeled to fit two Hubbert cycles. The first cycle represents surge production from the giant UK oil fields, Forties, Brent, Piper and Ninian. Actual cumulative production was 9937 million tonnes oil equivalent (mmtoe) 1970-2008 whilst the area beneath the two Hubbert curves is 9665 mmtoe - a difference of 2.7%.

To what extent the second Hubbert cycle will describe the decline in oil and gas production is highly pertinent but also uncertain. There are signs that the decline trajectory has already been influenced by a third cycle of giant field development with the Buzzard oil field and Ormen Lange gas field both coming on stream in 2007. The impact of this third cycle is shown below the fold.

This is a guest post by Jean Laherrère, the second of a series on the current knowledge of the deepwater Oil and Gas reserve at the Gulf of Mexico. In this second installment Jean analyses the Methane Hydrate resource of the region, in face of recent claims of great drilling results in the region.

The first article of the series, on the conventional Oil and Gas reserve, can be found here. Thanks to ace's diligence an error was identified and corrected, resulting in an update to the graph on Commulative Oil and Gas Discovery over 400 meters deep.

World oil production peaked in July 2008 at 74.82 million barrels/day (mbd) and now has fallen to about 71 mbd. It is expected that oil production will decline slowly to about December 2010 as OPEC production increases while non-OPEC production decreases. After 2010 the resulting annual production decline rate increases to 3.4% as OPEC production is unable to offset cumulative non-OPEC declines. The forecast from the IEA WEO 2008 is also shown for comparison.

The US Energy Information Administration (EIA) and the International Energy Agency (IEA) should make official statements about declining world oil production now to renew the focus on oil conservation and alternative renewable energy sources.

Saudi Arabia's historical crude oil production indicates a peak of 9.6 million barrels/day in 2005. In 2008, crude production was 9.3 mbd. In 2009 it is forecast to be 8.1 mbd followed by an increase in 2010 to 8.5 mbd. Unfortunately, after 2010 a steady decline is forecast.

The forecast production profile assumes that Saudi Arabia's ultimate recoverable crude oil reserves (URR) are 185 billion barrels (Gb). However, it is possible that Saudi Arabia could have an additional 25 Gb from discovered undeveloped fields and future discoveries. A higher URR of 210 Gb implies that the additional production increment could decrease the total decline rate from about 2015 as shown by the dashed line in the chart below.

The URR estimates in the chart above are made by using secondary data sources. In this time of economic crisis, it would appear appropriate for Saudi Arabia's oil fields to be publicly audited. The full disclosure of total remaining reserves, by field, would enable more effective future oil production and consumption planning in this post peak oil age.