Post on 08-Apr-2018
transcript
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 1/14
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 2/14
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 3/14
Yang, 1998), and some of the faults underwent slight
inversion in the late Paleozoic (Shumaker and Wilson,
1996).
The study area consists of weakly deformed, flat-
lying strata beneath the Appalachian Plateau. Outcrop-
ping Mississippian rocks are restricted to the leading
edge of the overthrust belt in the east and to the distal
western edge of the basin bordering the Cincinnati arch.
Between these outcrop belts, the subsurface Mississip-
pian rocks are overlain by 0–4000 ft (0–1200 m) of
Pennsylvanian strata. The Mississippian interval is pen-
etrated by approximately 10,000 wells (K. L. Avery,
Figure 1. Geologic location map of West Virginia study area, showing wells used and distribution of exposed MississippianGreenbrier carbonate rocks (gray shading) in the Appalachian Basin. Isopach contours (nonpalinspastic, in feet) show the total
thickness of Greenbrier carbonates, which thicken into the Appalachian foredeep to the southeast (modified from Pryor and Sable,1974; MacQuown and Pear, 1983; Yeilding and Dennison, 1986; Dever et al., 1990; Sable and Dever, 1990; Dever, 1995). Crosssection BB0 is shown in Figure 5.
Wynn and Read 1871
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 4/14
2006, personal communication), 193 of which were
used for this study, along with one core and eight out-
crop sections (Figure 1), which are described in Al-
Tawil et al. (2003).
Regional Stratigraphic Framework and Facies
The stratigraphy and biostratigraphy of the Missis-
sippian system in Virginia and West Virginia are given
in Reger (1926), Butts (1940, 1941), Wells (1950),Flowers (1956), de Witt and McGrew (1979), Rice
et al. (1979), and Maples and Waters (1987). The rocks
in this area overlie the Price and Borden formations
(Kinderhookian–middle Osagean) in the northeast
(Branson, 1912; Butts, 1940, 1941; Bartlett, 1974; Bjer-
stedt and Kammer, 1988) and the Fort Payne and Salem
Formation (late Osagean– early Meramecian) (Bjerstedt
and Kammer, 1988; Sable and Dever, 1990; Khetani
and Read, 2002). The Greenbrier Group and the lower
Bluefield Formation (Lillydale Shale, Glenray Limestone
Member, and Reynolds Limestone Member) make upthe study interval and are 0–3000 ft (0–900 m) thick.
These units are overlain by upper Mississippian and
Pennsylvanian siliciclastic rocks.
Regionally, the Greenbrier units on the shallow
ramp consist of shallow-water carbonates and minor
siliciclastic units. They thicken to more than 2000 ft
(600 m) toward the southeast into the proximal fore-
land, where they are dominated by thick slope muds,
which are intercalated with thin, shallow-water units
of quartz sandstone and limestone.
Al-Tawil et al. (2003) provided the first detailed
sequence-stratigraphic framework for the region based
on the eastern outcrop belt and limited subsurface data.
The Mississippian facies of the eastern Appalachian Ba-
sin are shown schematically on an idealized ramp mod-
el (Figure 2) and resemble contemporaneous facies de-
scribed elsewhere in North America by Leonard (1968),
Ettensohn et al. (1984), Carney and Smosna (1989),
Smith and Read (1999, 2001), Al-Tawil and Read (2003),
and Al-Tawil et al. (2003). Over much of West Vir-ginia, facies consist of terrigeneous red beds, quartz
peloid eolianite, lagoonal muddy carbonate, ooid- and
skeletal grainstone-packstone shoal complexes, and on
the ramp slope, deeper water dark-gray wackestone-
mudstone, and dark-gray laminated argillaceous lime
mudstone. The facies and their environments of depo-
sition are summarized in Table 1.
METHODS
Data were collectedfrom193 wells with cuttings, along
with one core and seven outcrop sections from pre-
vious studies (Wray, 1980; Yeilding, 1984; Yeilding and
Dennison, 1986; Al-Tawil, 1998; Al-Tawil et al., 2003).
The coarse fraction (1–2 mm; 0.04–0.08 in.) of the
cuttings for each sample interval (typically 10 ft [3 m])
was washed, acid-etched (2.5% HCl) and, if dolomitic,
was stained with Alizarin Red S and examined under a
binocular microscope. For each sample interval, rock
Figure 2. Schematic facies profile for the Mississippian carbonates of the Appalachian Basin. Actual facies distributions are morecomplex, in that skeletal grainstone-packstone and ooid grainstone facies are not only developed on the ramp margin, but also inlocal areas far back in the ramp interior.
1872 Geohorizons
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 5/14
types were classified according to Dunham (1962) and
counted to determine the relative abundance of rock
types. Percentages were recorded on data sheets, en-
tered into a commercial spreadsheet program, and saved
as comma-delimited files. Undergraduates helped clas-
sify and count the well cuttings and were overseen for
quality control by the senior author. This helped to
obtain and process the large amount of data required.For each well, the comma-delimited files were imported
into a commercial log-plotting program and plotted
against depth to form a percent lithology log. Well-
cuttings data for the 193 wells were calibrated against
geophysical logs where available, with gamma-ray and
bulk-density logs being the most useful. Wire-line logs
were digitized and exported as Log Ascii Standard files
and imported into a commercial log-plotting program.
The logs were then plotted alongside the cuttings-
percent logs, after adjusting the logs by 10 ft (3 m) or so
for best match with diagnostic markers (fine siliciclas-tics, oolite) to consider drilling lag. The correlation of
gamma-ray and bulk-density logs with the cuttings data
helped remove errors caused by the drilling lag. The
combination of cuttings-percent logsand gamma-raylogs
wasused to produce lithologic columns with a resolution
of 10 ft (3 m), showing dominant lithology and gamma-
ray response. The gamma-ray and bulk-density logs,
when combined with well-cuttings data, also made it
possible to identify and locate depths and thicknesses
of siliciclastic units thinner than the well-cuttings sample
interval. Five to six distinctive gamma-ray marker hori-zons are associated with several regionally extensive silic-
iclastic units, which are mostly transgressive shale inter-
vals. These regionally extensivegamma-raymarkers were
used to help constrain correlations between the wells.
The cuttings-based well sections were used to pro-
duce three dip-oriented and two strike-oriented strati-
graphic cross sections. Using these five cross sections
as a framework, the sequence picks were extended to
nearby wells, guided by log signatures where distinc-
tive. For each sequence, the following data were re-
corded in a spreadsheet: county, permit number, latitudeand longitude, sequence number, sequence thickness,
lowstand-transgressive systems tract thickness, lowstand-
transgressive systems tract dominant facies, the high-
stand systems tract thickness, dominant highstand fa-
cies, aggregate grainstone thickness in the sequence,
dominant marine grainstone type (skeletal, ooid, or pe-
loid), aggregate sandstone thickness, caliche (present or
absent), and produced fluid (oil, gas, or oil and gas). The
data for each well were then imported into a geographic
information system (GIS) and plotted as point themes.
The well sections with their sequence-stratigraphic
picks were compiled into regional cross sections show-
ingthe vertical and lateral distribution of facies(Figure 3).
Sequence boundaries and maximum flooding surfaces
were traced from section to section, guided by distinc-
tive log markers and biostratigraphy. This generated
a high-resolution sequence-stratigraphic framework
(Figures 3, 4). With the well data in GIS, the succes-sion throughout the region of interest was then time
sliced into sequences and systems tracts (Figure 5).
Lowstand-transgressive and highstand dominant
facies maps, isopach maps, and isolith maps were pro-
duced in GIS for each sequence using the data from the
point themes. The isopachs and isolith maps were pro-
duced using computer contouring software, edited by
hand, and then imported into GIS. Isopach maps were
constructed for individual sequences and systems tracts
(Figure 5). In addition, maps showing the dominant fa-
cies could then be rapidly made for each systems tract todefine geographic facies distribution and major poten-
tial reservoir trends. Grainstone isolith maps (Figure 5)
were generated to show the location of the primary
reservoirs. The maps and cross sections (Figures 3, 5) il-
lustrate the power of using sequence analysis of well cut-
tings within GIS to generate a high-resolution sequence-
stratigraphic framework for carbonate successions.
FACIES STACKING IN WELLS ANDSEQUENCE ANALYSIS
The conversion of cuttings data into dominant lithol-
ogy for a sample interval is needed to consider effects
related to interbedding of different lithologies and the
relation of the sample interval to the lithologic bound-
aries. All of these effects could result in the mixing of
lithologies within a sample interval.
Problems Caused by Mixing of Interbedded Lithologies
Interbedding can give the appearance of mixing in well
cuttings and can be a major problem if not recog-
nized. Two types of interbedding cause problems when
working with well cuttings: thin interbedding of rock
types, and larger scale stratigraphic juxtaposition of
two or more lithologies within the sample interval
(Figure 6A, B). Thinly interbedded lithologies com-
monly occur as pairs of rock types (i.e., shale inter-
bedded with limestone) in the sample interval, with
individual beds being below the resolution of the logging
Wynn and Read 1873
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 6/14
Table 1. Greenbrier Group Facies
Lithofacies Description Biota Depositional Environment
Red beds Red, maroon, and green mottled
mudrocks and siltstones, massive,
to laminated, rare current- and
wave ripples on siltstone interbeds,
rare mudcracks.
Root and burrow
traces in paleosols.
Subaerial to marginal
marine
Gray shale Dark-gray to olive-green clay and
silt, poorly fissile to massive.
Poorly fossiliferous to very
fossiliferous. Mollusks,
ostracods, some echinoderms,
brachiopods, and bryozoa;
biota sparse and restricted
in updip shale.
Lagoonal
Quartz sandstone and
calcareous siltstones
White to light-gray, well-sorted
fine- to medium-grained shaly
sandstones and siltstones of quartz, lesser carbonate grains,
cross-bedded to structureless;
flaser, lenticular, and wavy
bedded locally.
Rare Shoreline clastic
complex and
barrier siltstones
Anhydrite White-glassy, bedded, sometimes
sandy with dolomite.
None Sabkha
Caliche Yellow to brown, cryptocrystalline
and fibrous calcite crusts and fracture
fills; patches of caliche-coated
peloids and pisolites. Variably
silicified.
None Subaerial
Quartz peloidal
grainstone
Light to dark gray. Rounded, and
abraded peloids and some ooids,
abraded skeletal fragments, and
subangular very fine to fine
quartz up to 50%.
Abraded, rounded skeletal
fragments. No in-situ biota.
Coastal eolianite,
minor marine
sand sheets
Dolomite Yellowish tan. Poorly fossiliferous
to unfossiliferous. Fine-grained
dolomite crystals and may
include quartz silt and clay.
None to sparse, small
mollusks, small crionoids,
and ostracods.
Tidal flat
Fine-grained lime
wackestone-mudstone
Light-gray to creamy white,
unfossiliferous to moderately fossiliferous fine wackestone and
mudstone and pellet packstone.
Skeletal debris fine grained
and may contain quartz silt
and clay. Locally cherty.
None to sparse and may
have mollusks, smallcrinoid columnals,
ostracods. Small
oncolites, rare corals,
and brachiopods.
Low-energy lagoon
Peloid and ooid
grainstone
Light-gray to white, well-sorted, rounded,
medium to coarse grainstone
of sand-size ooids, peloids, lesser
skeletal fragments, and minor
intraclasts.
Crinoid, brachiopod,
bryozoan, and mollusk
fragments, forams.
High-energy shoal
1874 Geohorizons
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 7/14
tool, which then gives an average value for the thinly
interbedded units. Distinguishing this interbedding from
the mixing of superimposed rock types in the well cut-
tings is difficult. Where one lithology has far greater
abundance than the others, then it can be designated as
the dominant lithology for the interval; but when they
are subequal, both were considered dominant litholo-
gies for the interval (Figure 6A).
Mixing of lithologies in a sample interval also can
result from two or more lithologic units stacked withinthe sample interval. In a typical 10-ft (3-m) sample in-
terval containing three beds of different rock types,
each approximately 3 ft (1 m) in thickness, it is difficult
to locate the lithologic units in the section unless there
is a distinctive wire-line-log signal (e.g., shale, evapo-
rates, clean oolite). Where the percentage of each li-
thology is similar, it is also difficult to assign a dominant
lithology to the interval. Lithologies can be assigned
to the correct depth where one or more had a distinc-
tive wire-line-log signature (gamma ray or bulk densi-
ty; Figure 6B), for example, shale or shaley limestone(gamma ray), porous limestone, or anhydrite (density).
When these could not be differentiated in the logs,
there was no way to determine the actual succession
of lithologic units in the sample interval.
Sample Interval-Induced Mixing
Mixing can also result from the sample interval bound-
aries not being the same as the lithologic interval bound-
aries. Minimum mixing caused by sample spacing exists,
where the sample interval boundaries roughly coincide
with the major lithologic unit boundaries (Figure 6C).
However, if the sample intervals are larger than the
spacing of lithologic unit boundaries, then mixing of
lithologies in the interval results (Figure 6D). Again, the
assignment of the cuttings to actual depth in the sample
interval required a distinctive wire-line-log signature for
one or more of the lithologies.
Drilling-Induced Mixing
Mixing of well cuttings and contamination by caving
are, in most cases, caused by improper mud viscosity
(Hills, 1949). Low-viscosity drilling fluids do not al-
low a good mud cake to form on the wellbore, thus
allowing contamination from beds higher up in the
section. Improper mud viscosity allows well cuttings
from different sample intervals to mix, thus distorting
the primary stratigraphic succession in the well. How-
ever, with proper mud viscosity, well cuttings may
be held in suspension even when drilling stops (Hills,1949; Rider, 1996). Wells with improper mud viscosi-
ty can be recognized by a poor correlation to geophysi-
cal logs and by familiarity with the stratigraphy of the
region.
Sequence Analysis Using Cuttings
Sequences in the wells were recognized on the basis
of major landward and basinward shifts in diagnostic
facies belts (cf. Sarg, 1988; Kerans and Tinker, 1997),
Skeletal
grainstone-packstone
Light to medium-gray, variably
fragmented echinoderms, brachiopod,
bryozoa, mollusks, and rare ooids.
Mud-free grainstones to grain-rich
packstones and minor wackestones,
some with argillaceous seams.
Abundant echinoderms,
brachiopods, and
bryozoas; and
lesser mollusks.
Midramp and lagoonal
skeletal sheets and
shoals
Argillaceous skeletal
wackestone
Medium-gray to dark-gray echinoderm,
brachiopod, bryozoa, and lesser
mollusks; include wackestone and
lesser packstone; abundant lime mud;
terrigenous clay disseminated or
in seams and stringers.
Abundant echinoderm,
common brachiopods
and bryozoas, rare
mollusk.
Deep subtidal ramp
Laminated shaly
lime mudstone
Typically dark-gray, carbonate and
siliciclastic clay and silt.
None to sparse small
skeletal fragments.
Ramp-slope and basin
Table 1. Continued
Lithofacies Description Biota Depositional Environment
Wynn and Read 1875
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 8/14
1 8 7 6
G e o h o r i z o n s
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 9/14
such as eolianites, red beds, siliciclastic units, and lime
grainstone units. The sequence boundaries (Van Wagoner
et al., 1988) in outcrop are disconformities developed
on shallowing-upward carbonate units and commonly
are veneered with a thin paleosol or with transgres-
sive siliciclastics (Al-Tawil and Read, 2003; Al-Tawil
et al., 2003). In the sections produced from the cut-
tings, the sequence boundaries were arbitrarily placedbeneath red beds, sandstone, and shale that rest on
the underlying (highstand) carbonate (Figures 2 –4).
Along the ramp margin and slope, correlative confor-
mities arbitrarily were placed beneath the shallow-
water tongues (lowstand systems tracts) extending into
the dominantly deep-water successions (Figures 2 –4).
In wire-line logs from the shallow ramp, many sequence
boundaries, and some parasequence boundaries, have
high gamma-ray response caused by the presence of
the overlying terrigeneous mudrocks, shale, or argil-
laceous silty dolomite above the sequence boundary(Figures 2–4). Over most of the shallow ramp in West
Virginia, these siliciclastic-prone units are considered
to be transgressive deposits, deposited during initial
flooding onto the platform. However, possible low-
stand units are preserved locally on the shallow ramp
in the form of eolianite and caliche. Carbonate-prone
units were placed in the highstand systems tract, with
the maximum flooding surface being placed at the
transition from siliciclastic to carbonate lithologies,
or beneath the deepest water carbonate unit in the
sequence.
DISCUSSION
In carbonate successions with interbedded siliciclastic
units, such as the Mississippian succession described
here, cuttings provide a valuable data set based on ac-
tual lithologies drilled within the sample interval. In
fact, they provide the only direct sampling of the rocks
in uncored intervals. The cuttings data, when tied intothe wire-line logs, can be used to generate reasonable
representations of the lithologic successions in the drilled
section. Wire-line logs alone cannot provide reliable,
definitive facies recognition in these carbonate-prone
units, but need to be integrated with cuttings and/or
core data.
In lithified units such as these Mississippian car-
bonates that lie at depths less than a few thousand feet,
mixing caused by caving appears to be much less impor-
tant than mixing where the sample interval spans lith-
ologic boundaries, interbedding of lithologies, and de-
velopment of parasequences of two or more lithologiesthat are at or below the scale of the sample intervals.
Many of the best cuttings suites in mature basins
are in the early wells. These wells should be incorpo-
rated into the data sets, even if their wire-line-log suites
are not as good as those in newer wells, especially if
wire-line-log suites are available from nearby wells.
The detailed cuttings-based lithologic logs of the
well section (Figure 4) and the resulting cross sections
(Figure 3) showing the high-resolution sequence stra-
tigraphy in this article could not have been generated
without the cuttings data because of the scarcity of core and because the wire-line-log data do not provide
unique lithologic discrimination in carbonate rocks.
This cuttings-based analysis has provided the first state-
wide subsurface picture of the Mississippian Green-
brier carbonate reservoirs in West Virginia. The region-
ally mappable sequences are fourth order instead of
third order (cf. Weber et al., 1995; Al-Tawil et al.,
2003). As such, the time-slice maps have a quite high
resolution and provide valuable information on differ-
ential subsidence of the foreland, apparently associated
with the numerous basement faults that dissect theforeland. The cross sections illustrate that these se-
quences are regionally mappable, and tectonic subsi-
dence determines regional thickness changes (Al-Tawil
et al., 2003). The generalized facies distribution for
each sequence defined by the cuttings, maps out the
midramp grainstone fairways bordering the basin, as well
as smaller grainstone areas farther updip. This is the
first time that these facies belts have been defined re-
gionally for the subsurface. Given the complexity of
the stratigraphic succession, with its numerous deposi-
tional sequences, rapid vertical and lateral facies changes,as well as rapid lateral thickness changes caused by syn-
sedimentary tectonics, it is no wonder that a detailed
regional picture and interval correlations had not been
developed previously for these rocks.
Figure 3. Using the cuttings and wire-line logs, it is possible to generate high-resolution sequence-stratigraphic cross sections, suchas this one (BB0 of Figure 1). The upper units were hung from the Lillydale Shale marker, but the lower sequences were hung fromthe base of the upper Taggard equivalent (quartz peloid eolianites and calcareous siltstones at the base of sequence C6). The crosssection clearly shows the likely distribution of potential oolitic and siliciclastic reservoir facies and potential flow barriers and seals.
Wynn and Read 1877
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 10/14
Figure 4. Comparison of core and cuttings data, showing sequence picks between Sun Oil 2 core and Greenbrier 22 (cuttings), theclosest well analyzed. Greenbrier 22 is updip of the Sun Oil well across a down-to-basin fault, hence, the thickness difference. Goodcorrelation of the sequences between the two exists. Parasequences are picked on the core, but are not able to be picked with thecuttings data generally.
1878 Geohorizons
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 11/14
Figure 5. Examples of maps of individual sequences and systems tracts generated using the cuttings. The high-resolution sequence frasequences to be generated, showing major flexures, highs, and lows at that time. The cuttings data can be used to generate maps showing the dlowstand-transgressive systems tract, or highstand systems tract, as well as isolith maps to illustrate the likely location of thick potential rese
Wy n n a n d R e a d
1 8 7 9
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 12/14
Outcrop analogs indicate that this cuttings-based,
high-resolution picture is still highly simplified, because
the parasequences that make up many of the sequences
are beyond the resolution of the cuttings (Figure 4).
This highlights the importance of using outcrops or
core where available to obtain a detailed picture of stacking patterns in the subsurface, as it is probably
the parasequence-scale changes that ultimately con-
trol the actual location of reservoir units and inter-
vening baffles and barriers to flow. In addition, the re-
gional scale of this study precluded closer well spacing;
thus, lateral porosity changes within a field associated
with, for example, mapping of individual tidal ooid
bars (Kelleher and Smosna, 1993), are far beyond the
resolution of the study, but obviously are of utmost
importance. Finally, the approach can provide a se-
quence framework for the interpretation of more lo-
cal, high-resolution 3-D seismic surveys, providing a
merging of old and new technologies.
CONCLUSIONS
This study analyzed the Mississippian Greenbrier car-
bonates of the Appalachian Basin in West Virginia to
show how well cuttings and wire-line logs can be used
to generate a sequence-stratigraphic framework of car-
bonates in the subsurface.
Well cuttings from 193 wells were classified ac-
cording to Dunham (1962), tied to the wire-line logs,
placed in GIS, and used to determine the vertical stack-
ing of lithologies in each well and to pick sequence
Figure 6. Diagram illustrating mixing of cuttings in wells through heavily lithified units. (A) Small-scale interbedding of two or morelithologies within the sample interval results in mixed cuttings, with no information as to whether they are interbedded or merely make up a part of the sample interval unless one lithology has distinctive log signature, e.g., shale. (B) Individual lithologic units thatare smaller than the sample interval result in mixed cuttings, which again require a distinctive log signature to relocate. This situation
makes picking parasequences difficult in cuttings. (C) Unusual case where boundaries of lithologic units coincide with samplinginterval boundaries; this is one of few cases where there is minimal mixing caused by stratigraphy. (D) Boundaries of lithologic unitsdo not coincide with sampling interval boundaries; this results in the lithology spanning the sampling interval boundary being mixedinto the overlying and underlying sample bags.
1880 Geohorizons
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 13/14
boundaries and flooding surfaces. The well sections were
used to construct regional cross sections with wells
correlated using regionally extensive gamma-ray mark-
ers, allowing sequence boundaries to be traced. Isopach
maps were generated for each sequence, along with
dominant facies maps of systems tracts, and isolith
maps were used to display the distribution of major
potential reservoir facies. The GIS time-slice maps pro-vide the first statewide view of potential Big Lime res-
ervoir trends and associated facies in West Virginia at
the fourth-order sequence scale.
Where seismic data are limited, well cuttings and
wire-line logs can provide a crucial data set for sequence-
stratigraphic analysis. In areas where seismic data are
available, well cuttings can provide the necessary li-
thologic data to aid in seismic interpretation where core
coverage is limited. Three-dimensional mapping of the
sequence-stratigraphic time slices and the resulting iso-
pach maps of the sequences can clarify subtle differen-tial subsidence patterns, help identify subtle regional
structures that are spatially too complex to be evaluated
by two-dimensional cross sections, and help better un-
derstand the complex interplay between tectonics and
glacioeustasy.
REFERENCES CITED
Al-Tawil, A., 1998, High-resolution sequence stratigraphy of late
Mississippian carbonates in the Appalachian Basin ( WestVirginia, Virginia, Kentucky): Doctoral thesis, Virginia Poly-technic Institute and State University, Blacksburg, Virginia,109 p.
Al-Tawil, A., and J. F. Read, 2003, Late Mississippian (lateMeramecian– Chesterian), glacio-eustatic sequence develop-ment on an active distal foreland ramp, Kentucky, U.S.A., in
W. M. Ahr, P. M. Harris, W. A. Morgan, and I. D. Somerville,eds., Permo-Carboniferous carbonate platforms and reefs: SEPMSpecial Publication 78, p. 33– 54.
Al-Tawil, A., T. C. Wynn, and J. F. Read, 2003, Sequence responseof a distal-to-proximal foreland ramp during Mississippianglacio-eustasy, Appalachian Basin, eastern U.S.A, in W. M.Ahr, P. M. Harris, W. A. Morgan, and I. D. Somerville, eds.,
Permo-Carboniferous carbonate platforms and reefs: SEPMSpecial Publication 78, p. 9–32.
Bartlett, C. S. Jr., 1974, Anatomy of the lower Mississippian delta insouthwestern Virginia: Doctoral thesis, University of Tennes-see, Knoxville, 372 p.
Bjerstedt, T. W., and T. W. Kammer, 1988, Genetic stratigraphyand depositional systems of the Upper Devonian–lower Mis-sissippian Price-Rockwell deltaic complex in the central Ap-palachians, U.S.A.: Sedimentary Geology, v. 54, p. 265–301.
Boswell, R. M., and A. C. Donaldson, 1988, Depositional archi-tecture of the Upper Devonian Catskill delta complex; centralAppalachian Basin, U.S.A, in N. J. McMillan, A. F. Embry, andD. J. Glass, eds., Devonian of the World; Proceedings of theSecond International Symposium on the Devonian System,
v. 2, Sedimentation: Canadian Society of Petroleum GeologistsMemoir 14, p. 65–84.
Branson, E. B., 1912, A Mississippian delta: Geological Society of America Bulletin, v. 23, p. 447–456.
Butts,C., 1940, Geology of theAppalachian Valleyin Virginia:PartI.Geologic text and illustrations: Virginia Division of MineralResources Publication, 568 p.
Butts, C.,1941,Geologyof the AppalachianValleyin Virginia: PartII.Fossil plates and explanations: Virginia Division of Mineral Re-
sources Publication, 568 p.Carney, C., and R. Smosna, 1989, Carbonate deposition in a shal-
low marine gulf: The Mississippian Greenbrier Limestone of the central Appalachian Basin: Southeastern Geology, v. 30,p. 25–48.
Coffey, B. P., and J. F. Read, 2002, High-resolution sequence stra-tigraphy in Tertiary carbonate-rich sections by thin-sectionedwell cuttings: AAPG Bulletin, v. 86, p. 1407–1415.
De Witt, W., and L. W. McGrew, 1979, The Appalachian Basinregion, in L. C. Craig and C. W. Connor, eds., Paleotectonicinvestigations of the Mississippian system in the United States:Part I. Introduction and regional analyses of the Mississip-pian system: U.S. Geological Survey Professional Paper 1010,p. 13–48.
Dever, G. R. J., 1995, Tectonic implications of erosional and de-positional features in upper Meramecian and lower Chester-ian (Mississippian) carbonate rocks of south-central and east-central Kentucky: Doctoral thesis, University of Kentucky,Lexington, Kentucky, 157 p.
Dever, G. R., S. F. Greb, J. R. Moody, D. R. Chestnut, R. C.Kepferle, and R. E. Sargeant, 1990, Tectonic implications of depositional and erosional features in Carboniferous rocks of south-central Kentucky: Field guide for Annual Field Confer-ence of the Geological Society of Kentucky, 53 p.
Dunham, R. J., 1962, Classification of carbonate rocks according totheir depositional texture, in W. E. Ham, ed., Classification of carbonate rocks: AAPG Memoir 1, p. 108–121.
Ettensohn, F. R., 1994, Tectonic control on formation and cyclicityof major Appalachian unconformities and associated strati-
graphic sequences, in J. M. Dennison and F. R. Ettensohn, eds.,Concepts in sedimentology and paleontology: Tulsa, SEPM(Society for Sedimentary Geology), v. 4, p. 217–242.
Ettensohn, F. R., C. L. Rice, G. R. Dever, Jr., and D. R. Chesnut,1984,Slade and Paragon formations— New stratigraphic nomen-clature for Mississippian rocks along the Cumberland Escarp-ment in Kentucky: U.S.Geological Survey Bulletin, v. B 1605-B,37 p.
Flowers, R. R., 1956, A subsurface study of the Greenbrier Lime-stone in West Virginia: Part 1: Producers Monthly, v. 20,p. 26.
Henika, W. S., 1994, Internal structure of the coal-bearing portionof the Cumberland overthrust block in southwestern Virginiaand adjoining areas, in O. G. Dishner, ed., Geology and mineral
resources of the southwest Virginia coalfield: Charlottesville,Virginia, Commonwealth of Virginia Department of Conserva-tion and Economic Development, Division of Mineral Resources,p. 101– 120.
Hills, J. M.,1949,Sampling andexamination of well cuttings: AAPGBulletin, v. 33, p. 73– 91.
Kelleher, G. T., and R. Smosna, 1993, Oolitic tidal-bar reservoirs inthe Mississippian Greenbrier Group of West Virginia: AAPGStudies in Geology 35, p. 163–173.
Kerans, C., and S. W. Tinker, 1997, Sequence stratigraphy andcharacterization of carbonate reservoirs. SEPM Short CourseNotes No. 40, 130 p.
Khetani, A. B., and J. F. Read, 2002, Sequence development of amixed carbonate-siliciclastic high-relief ramp, Mississippian,
Wynn and Read 1881
8/6/2019 Sequence Strati Graphic Analysis Using Well Cuttings
http://slidepdf.com/reader/full/sequence-strati-graphic-analysis-using-well-cuttings 14/14
Kentucky, U.S.A: Journal of Sedimentary Research, v. 72,p. 657– 672.
Leonard, A. D., 1968, The petrology and stratigraphy of upperMississippian Greenbrier limestones of eastern West Virginia:Doctoral thesis, West Virginia University, Morgantown, WestVirginia, 245 p.
MacQuown, W. C., and J. L. Pear, 1983, Regional and local geo-logic factors control Big Lime stratigraphy and exploration forpetroleum in eastern Kentucky, in M. K. Luther, ed., Pro-
ceedings of the Technical Sessions, Kentucky Oil and Gas As-sociation 44th Annual Meeting: Lexington, Kentucky Geo-logical Survey, p. 1–20.
Maples, C. G., and J. A. Waters, 1987, Redefinition of the Mera-mecian/Chesterian boundary (Mississippian): Geology, v. 15,p. 647– 651.
Mazzullo, S. J., and A. M. Reid, 1989, Lower Permian platform andbasin depositional systems, northern Midland Basin, Texas, inP. D. Crevello, J. J. Wilson, J. F. Sarg, and J. F. Read, eds.,SEPM Special Publication 44, p. 305–320.
Pashin, J. C., and F. R. Ettensohn, 1995, Reevaluation of theBedford-Berea sequence in Ohio and adjacent states; forcedregression in a foreland basin: Geological Society of AmericaSpecial Paper 298, p. 68.
Pryor, W. A., and E. G. Sable, 1974, Carboniferous of the EasternInterior Basin, in G. Briggs, ed., Carboniferous of the south-eastern United States: Geological Society of America SpecialPaper 148, p. 281–313.
Reger, D. B., 1926, Mercer, Monroe, and Summer counties: WestVirginia Geological Survey, County Geologic Report CGR-28a,682 p.
Rice, C. L., E. G. Sable, G. R. Dever, and T. M. Kehn, 1979, TheMississippian and Pennsylvanian (Carboniferous) systems inthe United States–Kentucky: U.S. Geological Survey Profes-sional Paper 1110-F, p. 32.
Rider, M. H., 1996, The geological interpretation of well logs:Caithness, Whittles Publishing, viii, 280 p.
Sable, E. G., and G. R. Dever, 1990, Mississippian rocks in Kentucky:U.S. Geological Survey Professional Paper 1503, p. 125.
Sarg, J. F., 1988, Carbonate sequence stratigraphy, in C. K. Wilgus,B. S. Hastings, C. A. Ross, H. Posamentier, J. Van Wagoner,and C. G. S. C. Kendall, eds., An overview of the fundamen-tals of sequence stratigraphy and key definitions: SEPM SpecialPublication 42, p. 155–181.
Shumaker, R. C., and T. H. Wilson, 1996, Basement structure of the
Appalachian foreland in West Virginia; its style and effect onsedimentation, in B. A. van der Pluijm and P. A. Catacosinos,eds., Basement and basins of eastern North America: GeologicalSociety of America Special Paper 308, p. 139–155.
Smith, L. B. Jr., and J. F. Read, 1999, Application of high-resolutionsequence stratigraphy to tidally influenced upper Mississippiancarbonates, Illinois Basin: SEPM (Society for Sedimentary Ge-ology) Special Publication 63, p. 107– 126.
Smith, L. B. Jr., and J. F. Read, 2001, Discrimination of local and
global effects on upper Mississippian stratigraphy, Illinois Basin,U.S.A: Journal of Sedimentary Research, Section B: Stratigraphyand Global Studies, v. 71, p. 985 – 1002.
Vail, P. R., and R. M. Mitchum, Jr., 1977, Seismic stratigraphy andglobal changes of sea level: Part 1. Overview, in C. E. Payton,ed., Seismic stratigraphy; applications to hydrocarbon explo-ration: AAPG Memoir 26, p. 51–52.
Van Wagoner, J. C., H. W. Posamentier, R. M. Mitchum, P. R. Vail,J. F. Sarg, T. S. Loutit, and J. Hardenbol, 1988, An overview of the fundamentals of sequence stratigraphy and key definitions:SEPM Special Publication 42, p. 39–45.
Weber, L. J., J. F. Sarg, and F. M. Wright, 1995, Sequence stra-tigraphy and reservoir delineation of the middle Pennsylvanian(Desmoinesian), Paradox Basin and Aneth field, southwestern
U.S.A., in J. F. Read, C. Kerans, L. J. Weber, J. F. Sarg, andF. M. Wright, eds., Milankovitch sea-level changes, cycles, andreservoirs on carbonate platforms in greenhouse and ice-houseworlds: SEPM Short Course No. 35, Part 3, p. 1–81.
Wells, D., 1950, Lower middle Mississippian of southeastern WestVirginia: AAPG Bulletin, v. 34, p. 882–922.
Wray, L. L., 1980, Petrology and paleoenvironments of the upperMississippian Greenbrier Group, Spruce Knob Mountain, Pen-dleton County, West Virginia: Master’s thesis, West VirginiaUniversity, Morgantown, West Virginia, 152 p.
Yang, C., 1998, Basin analysis of the carboniferous strata in centraland southern West Virginia using sequence-stratigraphic prin-ciples: Morgantown, West Virginia, West Virginia University,350 p.
Yeilding, C. A., 1984, Stratigraphy and sedimentary tectonics of the
upper Mississippian Greenbrier Group in eastern West Vir-ginia: Master’s thesis, University of North Carolina at ChapelHill, Chapel Hill, North Carolina, 113 p.
Yeilding, C. A., and J. M. Dennison, 1986, Sedimentary response toMississippian tectonic activity at the east end of the 38thParallel fracture zone: Geology, v. 14, p. 621–624.
1882 G h i