This classification of exploratory wells was established by Frederic H. Lahee in 1944, and has been used since then by AAPG-CSD and API. It was widely adopted throughout North-America and is used with a few additions at well licensing procedure in Canada’s provinces and territories.
|Mnemonic||initial confidential status||Description|
|C||CONFIDENTIAL||NFW,NPW,TH,OV,EX wells are innitially confidential.|
|C||CONFIDENTIAL||OUT, DPT, DEV, DSW, REN wells are innitially confidential if all zones penetrated by the well are outside the limits of a designated pool or inside the boundaries of an existing confidential pool.|
|NC||NONCONFIDENTIAL||OUT, DPT, DEV, DSW, REN wells are innitially non-confidential if the well terminates in or just below a designated nonconfidential pool. If the well type and substance are production of crude bitumen in an oil sands area, the well is also nonconfidential.|
|CB||CONFIDENTIAL BELOW||OUT, DPT, DEV, DSW, REN wells are innitially non-confidential if one or more up-hole zones penetrated by the well is inside a designated nonconfidential pool. The confidential below formation name is the name of the deepest designated pool the well penetrates.|
|NC||NONCONFIDENTIAL||OTH wells are innitially non-confidential.|
A confidentiality assignment takes into account all zones to be penetrated by the well. After a well has been drilled, the operator may request a revision to its confidentiality assignment based on the result of drilling.