Oklahoma's API Issue

This blog is the latest in our series all about our favorite well identifier, the API number. We talk to a lot of users and we find that there is a lot of misunderstandings about what exactly the API number is and is not. This series is aimed at trying to help clear up some of those misunderstandings and give insight into how we handle the API issues and inconsistencies here at WellDatabase.

 

If you missed it, check out our blog - The History of the API Number.

That 13th & 14th Digit

Our previous blog outlined the history of the US UWI standard as well as a description of the US UWI as published by the PPDM Association. The ownership of this standard was transferred from the American Petroleum Institute to the PPDM Association in 2010. An industry work-group was subsequently formed to update the standard. This standard set forth instructions for assigning a 12-digit UWI with an additional 2-digit extension being optional. The following guidance was offered to encourage consistency in the assignment of the 2-digit extension:

Use positions 13-14 only to describe events that create physical configuration changes within the wellbore:

• Completions
• Plugbacks
• Conversions of well type if this involved recompletion (not just a change in status)
• Drilling modifications within the zone (if not deemed a new wellbore by the regulatory agency)

Never use position 13-14 to identify:

• Wellbores, including laterals
• Deepenings

Avoid using positions 13-14 to describe administrative events such as:

• Regulatory filings
• Subsequent permits
• Sundry notices
  
  

Oklahoma Issue

For many years prior to their adoption of RBDMS, the Oklahoma Corporation Commission (OCC) used a 10-digit identifier with an alpha suffix to denote the regulatory event. An example is 35-019-25019 shown below with the original number assigned by the OCC, the number imported into RBDMS after it was converted from the alpha version, and the correct number according to the US Unique Well Identifier Standard:

Please note that the 13^th and 14^th digits of the Well ID were incremented for each regulatory event, not the completion sequence. When you look at the OCC Well ID, it looks like the well has been recompleted 6 times but it has only been recompleted twice and the last one is questionable because they drilled out the bridge plug over the Woodford and commingled two existing sets of perforations in the Woodford and Sycamore. It is also worth mentioning that the OCC “zero fills” the 11^th and 12^th digit of the Well ID so identifying additional wellbores is not possible. This is truly a problem for wells drilled off pads and those with long wellbores because there is not an easy way to identify potential wellbore collisions and other environmental issues.

Historically, WellDatabase has used the UWI as reported by the OCC but going forward, WellDatabase will not increment the 13^th and 14^th digit of the Well ID for amendments and historical wells will be corrected in the future.