wheeler diagram and interpretation of wheeler diagram
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WHEELER DIAGRAM&
ITS USES IN EXPLORATIONAND EXPLOITATION IN
HYDROCORBONS
Presented by: Awais Ayub Awan Muhammad Umar
Muhammad Sajid
Presented to: Mr. Abdul Hannan
Group # 4
Wheeler Diagram Harry Eugene Wheeler ( History to Wheeler
diagram) Integrated data of Wheeler Diagram Application of Wheeler diagram in Exploration
and hydrocarbon exploitation Wheeler Diagrams related to base level changes,
system tracts, stratigraphic surfaces, Unconformity
Wheeler diagram of a fluvial to shallow-marine depositional sequence(Dip oriented stratigraphic succession)
Contents
Interpretation of Wheeler diagram of a fluvial to shallow-marine depositional sequence
Wheeler diagram on the base of well log data
(Pseudo Wheeler diagram)Calibration through Pseudo wheeler diagram
workflow for interpretation of Pseudo Wheeler Diagram
Geohistory diagram and location of well data
Application of Pseudo wheeler diagram
.
wheeler diagram related to interpretation of Coastal onlap curve
Wheeler transformation ( seismic based wheeler diagram
Uses of Wheeler diagram Conclusion References
A stratigraphic summary chart on which geologic time is plotted as the vertical scale, and distance across the area of interest as the horizontal scale, and on which a variety of stratigraphic information is brought together.
Display both the horizontal distribution of the contemporaneous component sedimentary layers of a sequence but also the significant hiatuses in sedimentation.
Wheeler Diagram
Stratigraphic summary chart It’s a spatio-temporal diagram Consist of x-axis and y-axis On x-axis plot distance of stratigraphic area
of interest On y-axis plot Geologic age ( absolute and
relative) of stratigraphic section
Wheeler diagram
On the cross section above the A5 surface is truncated by an unconformity but on this area-time plot of Wheeler (1964) the A5
surface extends across the entire region, with a large portion of it is within the lacuna domain
Wheeler diagram
American Geologist and Stratigraphic (1907 – 26 January 1987) A professor of geology at the University of
Washington from 1948 until 1976 Wheeler's work in the 1950 and 1960s was
pivotal in the later development of sequence stratigraphy
still used today, for example by Petroleum industry
Harry Eugene Wheeler
His 1964 paper, Baselevel, Lithosphere Surface, and Time-Stratigraphy evolved the concept of base level
To emphasize the continuous spatial and
temporal nature of stratigraphy, eventually giving rise to wheeler diagram.
Harry Eugene Wheeler
The contemporaneous component sedimentary layers
Systems tracts of sequences in terms of their relationship to baselevel, hiatuses, timing and geographic location.
Wheeler diagrams enable the analysis of a stratigraphic section
Outcrops dataCore dataWell logsSeismic data
Integrated data of Wheeler Diagram
Base level change Interplay between base level change and
sedimentation Interpretation of sedimentary environment Stacking pattern (Progaradation &
retrogradation) System tracts Sequences Surfaces
Application of Wheeler diagram
Unconformity Deposition Condensation Erosion Hiatus Hydrocarbon exploration Economic minerals Geologic time and thickness of formation Geographic distance of stratigraphic
succession
,
.
.
Depositional patterns during a full regressive-transgressive cycle
Base level Change
For the stratal stacking patterns of the four systems tracts
Their inferred timing relative to the base-level curve
Above Wheeler diagram illustrate
Subaerial unconformity extends basinward
Due to forced regression of the shoreline
correlative conformity meets the basinward termination of the subaerial unconformity
Appearance of fluvial onlap depends on topographic gradients
.
Grading trends (fining- vs. coarsening-upward) are temporally offset between shallow- and deep-water systems
Progradation of basin-floor fans continues throughout the regressive stage
onset of base-level rise marks a change from high-density to low-density turbidity currents
sand starts to be trapped
.
aggrading fluvial to coastal systems during lowstand normal regression
stratal architecture breakdown of a sequence into the four systems tracts
A full cycle of base-level changes consists of a succession of four distinct stages of shoreline shifts
(i.e., two normal regressions, one transgression and one forced regression)
.
Its logic in separating the products of deposition of four stages in the evolution of a sequence
Each stage of shoreline shift is associated with different economic opportunities
i. Petroleum plays, ii. Exploration strategiesiii. change markedly between the products of
forced regression and subsequent lowstand normal regression.
Correlative conformity marked the end of regression and base level fall
.
Wheeler diagram of a fluvial to shallow-marine depositional sequence(Dip oriented stratigraphic succession)
(1)Fluvial to shallow-marine depositional sequence
(2) Wheeler diagram
based on the Upper Cretaceous succession in southern Utah,
End of the estuary life time (end of transgression) is accompanied by an abrupt shift in fluvial styles upstream
It recognize nonmarine portion of the maximum flooding surface.
Interpretation of Wheeler diagram of a fluvial to shallow-marine depositional sequence
Landward shift of facies through time
Boundary between braided and meandering stream facies
Fining upward trend within the fluvial part of each systems tract.
Threshold of facies shift across the maximum flooding surface
Maximum flooding surface in fluvial successions indicated by an abrupt increase in fluvial energy, from meandering to overlying braided fluvial systems
End estuary life time triggers a rapid seaward shift of the river mouth ( delta)
Maximum flooding surface is indicated by a grain size.
.
Wheeler Diagram interpreted on the base of Well log data
Calibration through a 'pseudo Wheeler' diagram
A review of depositional episodes Tectonic/ Eustatic gaps, Allowing identification of correlations The relevance of the sea level curve
Pseudo Wheeler Diagram
1. Lithology
2. Sequence Stratigraphy
3. Environments and Facies
4. Lithostratigraphy
5. Chronostratigraphy
workflow for interpretation of Pseudo Wheeler Diagram
Geohistory diagram and location of well data
Pseudo Wheeler Diagram
Pseudo Wheeler Diagram
Identification of depositional episodes and Environments
Evaluation of tectonic/ eustatic gaps
Allowing identification of correlations
The relevance of the sea level curve
Petroleum play
Application of Pseudo Wheeler Diagram
Dip oriented stratigraphic succession and relationships of the facies and the ‘coastal’ onlap curve
.
Wheeler Diagram of Dip oriented stratigraphic succession and relationships of the facies and the ‘coastal’ onlap curve
Coastal onlap curve ‘Coastal’ onlap curve is use in the seismic and
sequence stratigraphy for the construction of the global cycle chart.
Composed mainly of a combination of fluvial and marine onlap.
‘Coastal’ onlap indicates stages of sea-level rise is misleading, and resulted in
the representation of sea-level fall as instantaneous events.
Wheeler transform is the seismic equivalent of the geologic Wheeler diagram.
Flatten the seismic data (or derived attributes) along flattened chrono-stratigraphic horizons.
The vertical axis in the Wheeler transformed domain is relative geologic time (as opposed to absolute geologic time)
Wheeler transform can be performed in 2D and 3D
Wheeler Transformation
Purpose; To flatten the seismic data while honoring
hiatuses caused by non-deposition and erosion.
Work flow; i. Select a pre-calculated chrono-stratigraphy
ii. Add a Wheeler scene and use the selected chrono-stratigraphy to flatten the seismic data (or attribute).
Wheeler Transformation
Wheeler Transformation
Wheeler diagram on base of seismic data
Wheeler diagrams provide a useful tool for hydrocarbon exploration when it used in junction with sequence stratigraphic principles.
Reservoir risks can be significantly reduced by using such charts
It use with sequence stratigraphic depositional models to identify potential sand-prone facies.
Conclusions and Uses
Interpretation of sedimentary environment Stacking pattern (Progaradation &
retrogradation) Unconformity Economic minerals
.
Principle of Sequence stratigraphy by Octuvian Catuneanu
Sequence stratigraphy by Emry Web search Google Books Google Imageswww.wikipedia.comwww.geology.comwww.scl.comStrata terminology site
Refrences
.
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