Print this pageCO2/Enhanced Oil Recovery and Geological Sequestration Potential in Northern Niagaran Pinnacle Reef Trend Reservoirs, Northern Lower Michigan, USA
Silurian Niagaran pinnacle reefs are the most prolific petroleum reservoirs in the Michigan basin, USA. At least 400 MMBO and 2.4 TCF of natural gas have been produced from over 1700 wells in over 800 northern Lower Michigan reef trend fields from reservoirs at depths of at least 2600ft to 7,000ft. The Northern Pinnacle Reef Trend (NPRT) comprises a giant hydrocarbon resource in closely-spaced, but highly compartmentalized oil and gas fields many of which have either reached or are nearing their economic limit in primary production mode. Geologically complex, carbonate reef reservoirs represent a significant opportunity for enhanced oil recovery and geological sequestration of CO2. The objective of this study is to evaluate the CO2/Enhanced Oil Recovery (CO2/EOR) and Geological Sequestration (GS) potential using 2 distinct approaches: 1) a produced fluid volumes approach, and 2) a gross storage capacity approach using petrophysical well logs and reservoir acreage data. These approaches provide lower and upper bounds (respectively) for GS potential in the NPRT. Estimates of CO2/EOR potential are also assessed based on recovery efficiencies observed in ongoing CO2/EOR projects in the area combined with NPRT cumulative oil production data.
Five Niagaran reservoirs in the NPRT have been converted to CO2/EOR floods by Core Energy LLC, Traverse City MI. High purity CO2, a byproduct of natural gas produced from the Devonian Antrim Shale, is recovered from a natural gas processing plant near the injection sites. This plant is one of several in the region cumulatively capturing more than 40 million cubic feet (nearly 2400 metric tons) of CO2 per day. Total projected Antrim Shale gas CO2 production for the remaining life of the play is estimated at 27 million metric tons (Mmt). This source of nearly pure CO2 provides the opportunity for large scale deployment of CO2/EOR in the NPRT.
Preliminary estimates of possible incremental CO2/EOR for the NPRT is estimated at 120-200MMBO using a range of CO2/EOR recovery efficiencies of 30-50%, relative to primary production. Preliminary GS capacity from total produced fluids analysis is estimated at 300Mmt of CO2. Approximately 550Mmt of CO2 storage capacity is estimated using trend average net porosity in NPRT reservoirs of 5.5 Ø-feet and reservoir acreage of approximately 115 thousand acres. Based on these estimates, substantial potential for CO2 /EOR and GS of additional anthropogenic CO2 exists in the NPRT of Michigan.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009