Modeled distribution of original reserves in 'Ain Dar/Shedgum area of Ghawar (left), oil water contact offset by 511' vertically upward (center) and the same with the effect of gas caps (right).
As some of you may know, I also blog at the Oil Drum, a collective website that focuses on energy issues. In recent weeks, a very thorough debate about the state of Ghawar, the largest oil field in the world and Saudi Arabia's crown jewel, has been taking place over there.
This week, Stuart Staniford, one of the editors of the site, has posted one of the most impressive blog posts ever - a massive 16,000 word analysis of publicly available data on the giant Saudi oil field, and his conclusions are all the more worrying that they are based on multiple threads of evidence: the field is close to irremediable decline.
I am posting the introductory paragraphs of his post below, but can only encourage you to read the whole thing and distribute it widely.
This analysis is a summary of my attempt to understand two pictures, which implicitly pose two questions.
The first picture is this:
Visualization of oil saturation in Ghawar, with focus region on 'Ain Dar and Shedgum regions at northern end. This is the "Linux Supercluster" picture (finder's credit Bob Shaw), showing a simulation visualization of the state of Ghawar at some year, probably but not certainly 2004. I have color reversed the original picture so that in this version, the red areas are interpreted to represent dry oil in the reservoir. The dark blue areas are water below the oil. The pale blue areas are interpreted to be swept, with most oil that can be removed already gone. Source: Figure 3 of Linux Clusters Driving Step Changes in Interpretation Simulation (pdf).
Here the question is: is this an accurate picture of the state of recent depletion of Ghawar? (Ghawar is the world's largest oil field, and source of over half of the oil produced by Saudi Arabia).
And if so, then the second question arises: does that depletion have anything to do with this picture?
Saudi Arabian oil production, Jan 2002-Jan 2007, average of four different sources. Annotations show important events causally influencing production, including all documented megaprojects for new supply in the the time period. Graph is not zero-scaled to better show changes. Click to enlarge. Source: US EIA International Petroleum Monthly Table 1.1, IEA Oil Market Report Table 3, Joint Oil Data Initiative, OPEC Monthly Oil Market Report, Table 17 (or similar) on OPEC Supply. See this essay for more details on data sources.
In particular, Saudi oil production has been falling with increasing speeed since summer 2005, and overall, since mid 2004, about 2 million barrels of oil per day in production has gone missing (about 1mbpd in reduction in total production, and about another 1mbpd in that two major new projects, Qatif and Haradh III, failed to increase overall production). That's 2.5% of world production and, if that production hadn't gone missing, gasoline in the US likely would still be somewhere in the vicinity of $2/gallon instead of well over $3.
I will analyze six or seven separate lines of technical evidence, and argue they all point to a consistent picture, which says that the answer to both questions is "Yes". Yes, the northern half of Ghawar is quite depleted. And yes, this probably explains at least part of recent production declines. Furthermore, it is likely that more declines in Saudi production are on the way.
The evidence in question comes from quantitative forensic correlation of hundreds of disparate pieces of data from dozens of technical papers about different aspects of Ghawar. Thus this analysis is very long and detailed - my apologies to the reader. It summarizes 300+ hours of work on my part, and probably similar amounts of work by several other members of the loose Oil Drum coalition investigating Ghawar and (most particularly Euan Mearns, who has posted his own thoughts and Fractional_Flow). It's just a lot of material to document. And in attempting to address both the detail needed by technical readers and the explanations needed by less-technical readers, the length has grown further. Given the importance of the subject, in a choice between being thorough and being brief, it seemed better to be thorough. I will at least do my best to be clear in my exposition.
Go read the full arguments here. And remember that this is the work of a blogger. This may be free, but it's priceless.
And here are the earlier posts and discussions that led to this work:
Stuart Staniford
by Euan Mearns
by Heading Out
by Ace
Please consider publicizing this work widely. If anything can dispel the myth of bloggers as unserious blatherers, this could be it - serious, documented, collective work with original, if disquieting, results.