MRCSP Phase I Geologic Characterization Report - Midwest ...
MRCSP Phase I Geologic Characterization Report - Midwest ...
MRCSP Phase I Geologic Characterization Report - Midwest ...
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72 CHARACTERIZATION OF GEOLOGIC SEQUESTRATION OPPORTUNITIES IN THE <strong>MRCSP</strong> REGION<br />
often very good because of enhanced secondary porosity, and would<br />
provide good areas for enhanced oil recovery. Within the subcrop<br />
trend, average porosities measured from core and geophysical logs<br />
range from 6 to 12 percent with values as high as 14 percent (Riley<br />
and others, 1993; Baranoski and others, 1996). Permeabilities<br />
vary widely from .01 to 198 md, averaging 4 md (Baranoski and<br />
others, 1996). Thickness of the Rose Run varies depending on the<br />
size of the remnant. Wells with a complete section of Rose Run in<br />
the subcrop trend have a gross thickness of approximately 110 feet<br />
and a net thickness of about 50 feet of highly porous, permeable<br />
sandstone. The subcrop trend of the Rose Run (Figure A4-1) is an<br />
attractive prospect for CO 2 injection.<br />
High porosities and permeabilities are not restricted to wells<br />
within the subcrop trend. Cores in Jackson and Scioto counties,<br />
Ohio, approximately 40 to 50 miles down dip from the subcrop,<br />
indicate average porosities ranging from six to 12 percent, and permeabilities<br />
often greater than 1.0 md, with some values exceeding<br />
100 md. These porosities and permeabilities indicate good reservoir<br />
quality away from the highly drilled and explored subcrop trend.<br />
Although the gross interval of the Rose Run thickens to the east,<br />
the sandstone-to-carbonate ratio decreases to the east and southeast,<br />
suggesting a clastic source to the north and northwest (Riley and<br />
others, 1993). Thus, net sandstone generally decreases to the east<br />
and southeast. The American Electric Power #1 AEP well drilled<br />
in New Haven, West Virginia, encountered only 18 net feet of<br />
sandstone greater than six percent porosity within the Rose Run.<br />
This well was drilled as part of a DOE-funded project to assess the<br />
potential injection for CO 2 sequestration.<br />
There has been no oil or gas production from the Rose Run in<br />
Kentucky, and there are fewer data to determine the composition,<br />
reservoir quality, and suitability of the Rose Run as an injection<br />
target. While the Rome trough was actively subsiding during Rose<br />
Run deposition, large amounts of clastic sediment were probably<br />
built up in localized areas of Kentucky, West Virginia, and Pennsylvania.<br />
Wells such as the Amoco #1 Svetz well in Somerset County,<br />
Pennsylvania, with approximately 470 feet of Rose Run, indicate<br />
the potential for large sequestration capacity at the greater depths in<br />
the Rome trough. Well logs in Kentucky indicate porosity up to 18<br />
percent at depths greater than 5,000 feet in the Rose Run.<br />
In most areas the Rose Run sandstone contains an adequate seal<br />
and confining units for CO 2 sequestration, as indicated by the trapping<br />
efficiency of significant volumes of oil and gas. The nonporous<br />
Beekmantown Formation dolostone and Wells Creek Formation<br />
that directly overlie the Rose Run provide an excellent seal for<br />
containment of CO 2. In some areas (e.g., south-central Kentucky),<br />
the Beekmantown is porous and is a hydrocarbon reservoir. The risk<br />
of an inadequate seal is higher in these areas, especially where the<br />
Beekmantown is fractured. In Ohio, a thick sequence of Ordovician<br />
shales and Black River and Trenton carbonates overlie the Rose<br />
Run and serves as a confining unit. Below the Rose Run, a thick<br />
sequence of Cambrian dolostone and shale act as the confining unit<br />
between the Rose Run and earlier Cambrian sandstones.<br />
To date there has been no injection activity in the Rose Run, thus<br />
data regarding CO 2 injectivity is not available. A DOE-funded pilot<br />
study is currently under consideration at the AEP New Haven site to<br />
inject CO 2 into the Rose Run and other potential units. This will provide<br />
critical data necessary for evaluating the injectivity in potential<br />
areas for Rose Run sequestration.<br />
5. KNOX TO LOWER SILURIAN UNCONFORMITY INTERVAL<br />
The stratigraphic sequence herein referred to as the Knox to<br />
Lower Silurian Unconformity Interval has been mapped because of<br />
its potential function as a major confining interval. This interval is<br />
dominated by thick, relatively impermeable carbonates at the bottom<br />
and thick shale sequences at the top. There is, however, some<br />
potential for carbon sequestration in several of the units, including<br />
the St. Peter Sandstone (which is mapped and discussed separately<br />
for this project), some of the fractured or dolomitized portions of the<br />
carbonate sequence, and the coarser clastics of the Bald Eagle and<br />
Juniata Formations at the top of the sequence in the eastern part of<br />
the <strong>MRCSP</strong> study area. The interval is bounded by two major unconformities,<br />
the Knox unconformity at the base and the Cherokee<br />
unconformity at the top (i.e., at the Ordovician-Silurian boundary).<br />
The stratigraphic nomenclature associated with the Knox to<br />
Lower Silurian Unconformity Interval can be intimidating (Figure<br />
5). Most of the laterally equivalent units shown in Figure 5 are<br />
lithologically similar, at least in the lower half of the correlation<br />
diagram, despite name changes across state boundaries. The stratigraphic<br />
nomenclature toward the top of the Ordovician sequence,<br />
however, becomes much more complex due to the multitude of<br />
westward prograding Upper Ordovician flysch facies resulting from<br />
the Taconic orogeny.<br />
ORIGIN OF NAMES, TYPE SECTION, SIGNIFICANT<br />
EARLIER STUDIES ON THIS INTERVAL<br />
The St. Peter Sandstone is the lowest (Middle Ordovician) strata<br />
in the Knox to Lower Silurian Unconformity Interval in the Michigan<br />
basin. However, because it is discussed in detail elsewhere in<br />
this report, it will not be mentioned further here except in reference<br />
to adjacent formations. In the following discussion, italicized state<br />
names in parentheses, for example (Michigan), indicate the use of<br />
the particular stratigraphic name in that state, whether or not it is a<br />
direct lithologic correlative of the type section.<br />
Calvin (1906) named the Middle Ordovician Glenwood Formation<br />
(Michigan) for a thin (3 to 15 feet) shale in Glenwood<br />
Township, Winneshiek County, Iowa, lying between the St. Peter<br />
Sandstone and the Platteville Limestone. The Ancell Group (Indiana),<br />
named by Templeton and Willman (1952) for rocks exposed<br />
in the Dixon-Oregon area of northern Illinois, comprises in ascending<br />
order, the Kingdom, Daysville, Loughridge, and Harmony Hill<br />
Formations. Lusk (1927) first used the name Wells Creek Formation<br />
(Kentucky, Ohio, West Virginia, and northwestern Pennsylvania)<br />
without explanation in a stratigraphic column of rocks in central<br />
Tennessee, apparently to replace Ulrich’s (1911) Wells Chert (the<br />
name Wells was already in use for a younger formation in Idaho<br />
and Utah). Bentall and Collins (1945) later described the Wells<br />
Creek Formation as 432 feet of tan to grayish green, silty to sandy,<br />
argillaceous, fine-grained dolostone interbedded with dark-brown to<br />
tan, dense limestone lying between the Knox unconformity and the<br />
Murfreesboro Limestone in the Ada Belle Oil #2-A well in Trigg<br />
County, Kentucky. Ulrich (1911) named the Bellefonte Formation<br />
of the Beekmantown Group (central Pennsylvania and Maryland)<br />
for 2,145 feet of light-gray, argillaceous, highly magnesian limestone<br />
and yellowish-gray or drab, generally fine-grained and occasionally<br />
laminated dolostone alternating with dark, finely crystalline<br />
dolostone at Bellefonte, Centre County, Pennsylvania. All of these<br />
formations are more or less equivalent in age and grade laterally<br />
with each other.<br />
Field (1919) recognized a zone of interbedded limestone and