DRRZD Legend and Map Directory

Deeper rights reversion was introduced into the Department of Energy’s tenure system in 1976. It allows for petroleum and natural gas rights below the base of the deepest productive zone to be deleted from a lease and returned to the land bank. This releases the rights that had been sterilized by shallow production and allows for further development. The Department of Energy’s Information letter 1998-14 discusses deeper rights reversion in detail.

Deeper rights reversion zone designation (DRRZD) - identifies a zone by its name. As noted in AER* Decision 95-10, historically the name of the zone identified within type wells takes precedence over the depths identified in terms of utilizing a DRRZD.

Environment and Resource Services has compiled a PDF library, showing the administrative areas of DRRZD’s as well as their respective type well log and interval. These files can be viewed using Acrobat Reader.

DRRZD Search Engine

Notes & Disclaimers

Note 1: Log Annotation Guide: For each DRRZD type well log, the interval is annotated with blue, and indicated further by an arrow within the interval. All other specified tops were provided on the AER database, and marked by a red line. For consistency, all depth numbers were recorded in red.

Note 2: Upon clicking one of the DRRZDs, you will be directed to a site with the map of that DRRZD as well as its type well log. In some cases a map may contain more than one DRRZD. If so, simply scroll through the pages after the map until you find the desired DRRZD log.


The type well, log and interval for each DRRZD were assigned by the Alberta Energy Regulator (AER).
All raster annotations were performed using the Imaging for Windows Application, via Microsoft.
Data represented on DRRZD map is for general information only.
User is responsible for verifying the data before making decisions based on these maps and reference wells.
Base Features found on DRRZD maps provided by Spatial Data Warehouse Ltd.

*Note: In 2013, the Alberta Energy Regulator (AER) succeeded the former Energy Resources Conservation Board. The AER provides full-lifecyle regulatory oversight of energy resource development in Alberta. Part of its responsibilities are the creation of DRRZDs and ZDs in accordance with the Oil and Gas Conservation Actexternal link icon . The department of Energy uses these to define the mineral rights granted in agreements.