MRCSP Phase I Geologic Characterization Report - Midwest ...

OIL, GAS, AND GAS STORAGE FIELDS
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injection pilot project. Should economical sources of CO 2 become
available to the region, it is imperative that we are prepared to use
this methodology to recover these additional natural resources.
GAS STORAGE
Consumer demand for natural gas is seasonal; higher demand
during extreme cold periods for home heating purposes and lower
demand during the warmer summer months. In general, natural gas
supplies are fairly constant because natural gas distributors utilize
underground gas-storage fields to maintain a reserve of gas for peak
demand periods.
The MRCSP region has more natural gas storage potential than
any other region of the country. In fact, four of the top seven states
in gas storage capacity are in the region (Figure 19)—Michigan
is the national leader. These statistics unequivocally indicate the
region contains exceptional geological formations for the underground
storage of both natural gas and CO 2, for that matter.
Most of the region’s storage fields (Figure 20) were once producing
gas fields. Later, many of these fields were converted to storage
reservoirs by drilling wells designed specifically for injection operations
and also by building pipeline and compressor station infrastructures
to support the conversion. Gas storage fields are designed
to allow the entire amount of working gas to be cycled in and out of
the field once each year. Typically, the storage fields are filled from
pipelines in the summer months for withdrawal when demand peaks
in the winter months.
The gas storage fields provide an excellent analogue for study
when examining CO 2 storage. By analyzing these fields, we can
better model the amount of CO 2 that can be stored in similar strata
or reservoirs, and learn more about the injectivity rates that different
reservoirs can be expected to handle. Such investigations will
allow us to better forecast how many wells, and over what size of
an area, will be needed for a specific CO 2 project. Furthermore, gas
storage fields may be a viable means for future use as CO 2 storage
fields—either permanent storage from a large CO 2 source, or as a
CO 2 buffer operation for a larger CO 2 EOR operation. Occasionally
a gas storage field will be offered for sale. Any future CO 2 producer
or EOR operator might find purchasing such a field cost efficient for
storage of CO 2, especially if the preexisting infrastructure could be
used. The MRCSP Phase II project will examine storage fields in
greater detail for these reasons.
Figure 19.—Gas storage capacity and ranking by state with MRCSP-member states highlighted. Data source: Natural Gas
Monthly, 2002.