Professor Heading Out at the The Oil Drum has posted A Picture of Depletion, the subject of which I reproduced to the left—a slice through the Abqaiq oilfield in Saudi Arabia.

(Heading Out is a senior faculty member in one of the energy production disciplines.)

For most people there was some one thing that brought the reality of Peak Oil home to them. For me it was this picture, from a paper by Dogru, Hamoud and Barlow in JPT in February 2004...It shows a vertical slice taken through the Abqaiq oilfield in Saudi Arabia, using an instrument that measures the relative fluid densities at different levels in the field.

The shape is that of the carbonate rock which is the oil reservoir, although the vertical scale has been exaggerated considerably to show the current contents of the field. By using different colors the authors have shown the different fluid densities, and these can simply be translated into four zones. Over time the field has been injected with water (the blue zone) and this has pushed up the oil (the green zone) into the wells. The red is the overlying gas cap. When the reservoir was untapped it was likely all red and green. After all these years of pumping you can see how little of the green—the oil—remains. The field is about 800 ft thick from top to bottom and about 1.5 miles below the surface. If there is a picture that speaks to depletion this to me, is it.

The post continues on with further discussion of the Saudi situation.