This week the US Geological Survey (USGS) reported that the Wolfcamp shale holds 20 billion bbl of technically recoverable oil. That is just one of the huge formations within the Permian Basin where nearly half the drilling rigs in the US are now reportedly working.
Image Source: Texas Historical Commission
Wolfcamp shale is the source rock for many old conventional fields which holds an estimated
- 20 billion bbl oil
- 12 Tcf of gas
- 1.5 billon bbl of natural gas liquids
The above totals are the mean of a range (from F95 to F5) as shown below. F95 represents a 95% chance of at least the amount tabulated.
- Oil: 11,430 to 31,468 MM bbl
- Gas: 7,887 to 27,310 Bcf
- Gas liquids: 698 to 2,926 MM bbl
These are estimates of what is technically recoverable without considering if they could be profitably produced.
The USGS will cover the rest of the Permian over the next year with assessments of the Spraberry and Delaware basins.
Estimated technically recoverable oil by unit (mean)
| ||MMBBL||BCF|| MMBBL|
|Wolfcamp A||5,815 ||4,652 ||465|
|Wolfcamp B Upper ||5,829 ||4,663 ||466|
|Wolfcamp B Lower||1,430||1,144 ||114|
|Wolfcamp C ||1,433||1,146||115|
|Wolfcamp D ||4,920 ||3,936||394|
|Wolfcamp Northern|| 521 || 417 ||42|
The Permian difference
The Wolfcamp assessment helps explain why so many drilling rigs area working in the Permian Basin. The number nearly equals activity in the rest of the US according to a recent report by the US Energy Information Administration. The Permian total of 218 exceeds every other country in the Baker Hughes International rig count. Canada is second with 176 and Saudi Arabia has 126 rigs working.
Drilling really matters
Drilling has shrunk in other shale plays as investments have migrated to the Permian where the cost of producing oil is lower. Production in the other plays has fallen as a result.