Satellite O’er the Desert is produced by someone calling himself “Joules Burn” (who says scientists lack a sense of humor)? JB was inspired by the careful effort by Oil Drum’s Stuart Staniford to sift through the limited information publicly available to try to ascertain the current production status of Ghawar, the world’s greatest oil field, which in recent years has accounted for perhaps 6% of total world oil production all by itself. I discussed the implications of Stuart’s findings in a post at Econbrowser and an article in Atlantic; (by the way, the publisher has now made the latter openly available to all).
JB’s contribution is to note that the satellite images from Google Earth allow us to identify the precise location of individual wells in the Arabian Desert. For example, the photograph below shows two wells side by side. By following their respective pipelines (an arching northeast curve from the well on the left, and a jagged southeast line from the well on the right), JB determined that the well on the left was producing gas, while the one on the right was producing oil.
You can then line up the locations of all the oil wells with known maps of the Ghawar oil field.
JB further is able to date specific Google images,
and in many cases match picture details against other known dates. The left panel below identifies the oil wells JB found for the northern part of Ghawar. The middle panel shows wells drilled some time since 2000, and the right panel wells drilled since 2003.
One of the most surprising things to me about JB’s results is how much of the recent huge increase in Saudi drilling effort seems to have been devoted to Ghawar itself, particularly the northern field which, if I am reading this correctly, cannot have much production potential left.
JB’s next task was to line these well sites up with publicly available technical reports (which typically intentionally concealed the exact location discussed) and with some of the conjectures and inference that Stuart arrived at. For example, Stuart concluded that the following published schematic of the height of the water-oil contour at different dates described the northernmost thumb of Ghawar:
JB superimposed Stuart’s inference on the satellite map of new wells and confirmed that no new wells have been drilled in the area presumed to have been all water by 1984, though there has been a surprising amount of activity just south of that area.
On the basis of the presumed alignment of the schematic with known depths, Stuart then inferred the three points indicated by the turquoise rectangles on the graph below, which plots the date on the horizontal axis and the depth of the oil-water contact on the vertical axis. If the trend that Stuart inferred from a number of other sources is accurate, Stuart’s graph implies that recent production would have come from about the 6000′ depth, near the top of the original reservoir.
JB believes he has been able to infer the specific locations of two wells described in a recent Saudi Aramco technical report, described as having been drilled in 2004 and 2006, and both placed near the 6000′ contour (indicated by the orange line).
Let me end by quoting a couple of JB’s own conclusions from this effort:
the re-drilling of Ghawar– even excluding the much lauded Haradh III increment– can justifiably be classified as the largest Saudi Megaproject, at least in terms of wells drilled. And given the observed fact that virtually all of Uthmaniyah and ‘Ain Dar have been filled in, there is considerably less room for further development to maintain current production rates.
At the time reflected by these graphics, there was probably remaining oil to be had in a thin layer at the top and in isolated pockets of stranded oil, but it can’t last long at historical production rates for this part of Ghawar.