Monday, February 28, 2011

The Curious Case of US Oil Production

I have lately been updating my oil production numbers and plots, first Oklahoma, Texas, and world (OTW) production then Saudi Arabia. In the OTW blog entry I mentioned that I was still working on a US production update.

Digging through my thousands of files, I was able to relocate the data for US oil production from 1857 to 2006. This data had been carefully constructed from various sources and I wrote a Leading Edge Seismos column using it in May 2008. Here is the daily production figure from that column:

Figure 1. Daily US oil production plot from 2008 Seismos column.

Since I finally found the data behind the plot, it seemed a simple matter to add the last 4 years of production  and format the plot like the others I had posted in this blog. 

Naturally, the first place to turn in such matters is the venerable BP Statistical Review.  But something was immediately confusing to me.  Note my data in Fig 1 shows annual production for the US (including offshore and Alaska) as 5.14 MMBO/D. The BP Review showed 6.84 million BO/D for the same year, a whopping 33% difference. Confused, I then checked the Energy Information Administration and found values similar to BP. 

Was I going crazy? I'm not getting any younger, you know. Maybe this was a case of some mild stroke that left me in a confused world. But no, the Seismos column was there as evidence. So maybe I just used bad data back then. But no, wikipedia shows the same thing, and I read a recent paper (Nashawi et al., 2010) containing a daily US production plot (fig 15) that syncs perfectly with mine. Here it is:

Figure 2. US production from Nashawi et al. (2010)

Well, research is what I do, so the chase was on. The result is summarized in Fig 3.  The data comes from my earlier research (green dots), BP Statistical Review 2010 (BP, red dots), the Energy Information Administration (EIA, blue dots), and one data point each from International Energy Agency (IEA, white triangle),  and American Petroleum Institute (API, white square).  The IEA number (244840  thousand tonnes per day) needs a bit of conversion.  Wolfram|Alpha shows this represents 1.68 x 10^9 barrels of oil, or 4.603 million barrels per day.  

Clearly, I would be curious to see a full series of production numbers from IEA or API, but have been unable to figure out if these groups keep historical data on the internet.  

Figure 3. The mystery in a nutshell.  My green trend is supported by 2008 and 2010 numbers from API and IEA.  Meanwhile, BP and EIA are about 30% higher.  What the heck is going on?

Figure 4. Detail of Fig 3 from 1960-2010

At this point I have no resolution to the mystery, I just wanted to lay it out for all to see.  It is hard to imagine this discrepancy is due to definitions of crude oil (e.g, is shale oil included? condensate? heavy oil?).  Any of these would be in the accounting noise, not a 30% difference.

Comments are welcome.


Liner, C., 2008, To peak or not to peak, The Leading Edge 27, 610.

Nashawi, I.S., Malallah, A., and Al-Bisharah, M., 2010,Forecasting World Crude Oil Production Using Multicyclic Hubbert Model, Energy Fuels, 24, 1788-1800.

Note: Along these same lines, North Dakota is producing more oil than ever.


Craig said...

Hi Chris,

The differences may be associated with type of product measured. For example, during 2010 US 'crude oil' production was ~5.5MMBOPD; US 'liquids' production was ~7.5MMBOPD.



moka said...

usually it is hard to say exactly what is the real production from a field and the failures summarized mainly because of the quality of production. But the main reason is the LNG production as Craig said. It could be high portion. Or maybe the cause could be where is the lease geographically and who is the owner of the production. Usually there is some standard practice how to calculate but if the staff changes or there are big changes in the structure of the production or methods it can cause difficulties becuse you can not change the numbers backwards. It is not a science:)as geophysics

Anonymous said...

Hey, Chris,

The BP numbers include LNG, as do the EIA totals exhibited on the homepage. If you select crude oil production alone on the EIA dropdown menu, click the UPDATE button and then wait, wait, wait...wait while the obscure "yes, I'm doing something" bar wiggles. Eventually the page with your original ~5.1 in 2006 number for crude oil production shows up. Or at least it did for me :-).

On the BP spreadsheet,if you mouse over the note in the bottom lefthand cell of the spreadsheet, voila, the note that LNG is included appears. Lousy formatting in both cases.

Check me, of course, on whether this explains the apparent discrepancy.