Zama 9 Pools CO2 Project

Enhanced oil recovery using Carbon Dioxide as miscible flooding injectant (CO2 EOR) can significantly improve oil recovery from certain conventional oil fields in Alberta. In the Zama Field, waterflooding the pinnacle pools have been partially successful throughout the area. Although oil pay can reach 100 meter or more, these pinnacles are typically small in areal extend, with significance variance in ultimate conventional recovery factors.

The applicant wishes to initiate a CO2 EOR flooding of nine (9) candidate pools in the Zama Field (Township 115 and 116, Range 5 and 6 West of the 6th Meridian). These pools were identified as suitable CO2 EOR candidates, and were selected on the basis of remaining EOR recoverable reserves, proximity to the Zama Gas Plant, the existence of at least 2 re-completable well bores (each of the pools has at least 2 wells) and current reservoir pressures relative to minimum miscibility pressures, which the applicant estimates to be generally near or above virgin reservoir pressures. Approval for acid gas injection was previously obtained, and injection has already been in place in one of the pools, the Zama Keg River Z3Z pool. The pool is showing a favourable oil production response to acid gas injection, which is encouraging for this project.

The applicant proposes to use acid gas (67% CO2, 33% H2S) available at the Zama Gas Plants (located at section 12-116-6W6) as a miscible flood solvent for this project. The Zama Gas Plants were designed to remove the acid gas component of solution gas (approximately 5% CO2 and 3% H2S) using an amine extraction process that generates an effluent acid gas stream of approximately 60-80% CO2 and 20-40% H2S. This effluent was previously processed through a Claus unit to generate elemental sulphur and sent to block or disposed into the Keg River formation using nearby acid gas disposal wells.

An estimated initial volume of 170 tonnes/day of CO2 (3.23 MMCFD) is expected to be available for CO2 EOR in the area, and will be pipelined to the candidate pools. The 9 candidate pools are within 4 miles of the Zama Gas Plant. The initial acid gas supply will be adequate to begin CO2/H2S flooding of 5 pools. Subsequent breakthrough of CO2/H2S would then be recycled into additional candidate pools in the area. The applicant estimates there could be adequate CO2 volumes over the next 10 years to flood the remaining 4 pools.

The 9 candidate pools have been on primary production or primary / waterflood with ultimate conventional oil recovery ranging from 17% to 81% of individual pool’s OOIP, with an average of 35% for the group. The CO2 EOR incremental recovery is estimated at 12% OOIP on average, or 3.2 million barrels for the 9 pools. Over a period of 16 years, 1 megatonne of CO2 could be sequestered by this single project.

If this project proves successful, there are over 306 pools defined by the EUB in the Zama field alone and 670 pools in the larger Shekilie and Zama basins (and more in other basins), hence replication of this project would only be limited to the volume of CO2 available for injection. This would also be a good example of using CO2 from a local source for CO2 EOR and sequestration of CO2 in Alberta.

The following reports are currently available for public access:

Quarterly reports are available upon request – please contact EIPA.