May 29, 2008

Why oil costs over $120 per barrel


Posted by Euan Mearns on May 28, 2008 - 6:30pm in The Oil Drum: Europe

Global Total Liquids production and oil price, January 2002 to present. Production data from the IEA, data files supplied by Rembrandt Koppelaar. Monthly average WTI oil prices from Economagic.

With oil reaching $135 / barrel, Oil Drum readership exceeding 30,000 unique visitors per day and many wild stories circulating in the MSM as to why oil prices are so high this post strives to explain why oil prices are rising exponentially.

Production and demand

The most significant feature of the chart up top is the dog leg in production growth in 2004. Prior to then the flow of new oil field projects combined with increasing utilisation of spare capacity allowed global oil production to grow and to meet much of the growth in demand.

In 2004, OPEC spare capacity fell close to zero (see below) and the world struggled for a number of reasons to bring on new supply to compensate for decline (see below). The slowing of production growth has meant new supplies are insufficient to meet growing demand and the price has gone up to balance the books. Higher prices stimulate conservation that may take the form of fuel efficiency (driving a smaller car) or abstinence (poor people being priced out of the energy market).

Every year a large number of new oil fields are brought on line. However, this does not directly translate to growth in supplies since amongst other things the production decline in existing fields needs to be replaced first:

new annual production capacity = consumption growth + annual decline + spare capacity growth


All oil wells, oil fields and oil provinces are exposed to a phenomenon called decline. Producing oil depressurises the sub-surface reservoirs and uses up the reserves. With time the proportion of water to oil that is produced in any well increases (increasing water cut) and this combined with depressurisation leads to declining oil flow rates.

Combined, these processes result in naturally declining production. It has been estimated that the global average decline rate is 4.5% per annum. (personal communication, Peter Jackson, CERA). What this means is that every year the global oil industry must bring on stream 3.8 million barrels per day new production just to compensate for decline (4.5% of 85 mmbpd). If less than 3.8 million bpd are commissioned then global oil production will fall and vice versa.