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Whitings Source of Black Gold?-UAE Algal mats & lime muds A link to Middle East carbonate source rock potential C.G.St.C. Kendall, Xavier Jenson & Eugene Shinn – PowerPoint PPT presentation

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Title: Whitings


1
Whitings Source of Black Gold?
-UAE Algal mats lime mudsA link to Middle
East carbonate source rock potential
  • C.G.St.C. Kendall, Xavier Jenson Eugene Shinn

Departments of Geological Sciences, University
of South Carolina, Jackson School of Geology,
University of Texas Austin, and Marine Science
Center, University of South Florida
2
Outline of Presentation
  • The Hypothesis
  • Overview of Arabian Gulf Reserves
  • Geological setting of Arabian Gulf
  • Modern lime mud cyanobacteria generation of
    Arabian Gulf
  • Bahamian Whitings Productivity, Sequestration
    Organic Matter
  • Geological setting of Arabian Gulf Oil Fields
    tie of hydrocarbon sequestered cyanobacterial
    remains in geologic section
  • Significance of Russian source rock study
  • Conclusions

3
Hypothesis
  • Significant Holocene accumulations of
    cyanobacteria lime mud in Arabian Gulf axis
    tidal zones
  • These sediments have source rock potential
  • Similar sediments have accumulated since Triassic
  • Ancient carbonate muds are source of significant
    petroleum reserves of Arabian Gulf region
  • The present is the key to the past!

4
Current Middle East Reserves
Crude Oil(BB) - Natural Gas (TCF)
  • Saudi Arabia 263.5 bbls 204.5 Tcf 8 Years
  • Iraq 112 bbls 109 Tcf
  • UAE 97.8bbls 212 Tcf
  • Kuwait 96.5 bbls 52.7Tcf
  • Iran 89.7 bbls 812.3Tcf
  • Oman 5.3 bbls 28.4 Tcf
  • Yemen 4.0 bbls 16.9 Tcf
  • Qatar 3.7 bbls 300.0 Tcf
  • Syria 2.5 bbls 8.5 Tcf
  • Bahrain 0.1 bbls 3.9 Tcf
  • TOTAL 675.1 bbls 1,748.2 Tcf

5
MIDDLE EAST FIELDS
Location of Middle Eastern Oil Fields
6
Oil Production - Arabian Gulf
  • Productive hydrocarbon section older to West
    Paleozoic younger at Arabian Gulf Coast
    Mesozoic youngest in East in Zagros Mts
    Upper Tertiary.
  • West to East production includes
  • Infra-Cambrian Salt
  • Silurian and Ordovician clastics Unaizah
  • Permian clastics carbonates Khuff
  • Upper Jurassic Carbonates - Arab Tuwaik Mt Grp
  • Lwr Cretaceous Carbonates Shuaiba Thammama
  • Middle Cretaceous Mishrif
  • Tertiary - Asmari
  • Mesozoic through Tertiary-Lime Mud Source

7
Proposed Concept
  • Arabian Gulf Holocene cyanobacteria mud
    accumulations significant in axis tidal zones
  • These sediments have source rocks potential
  • 4000 meters of similar sediments have accumulated
    here since Triassic
  • Sequestered ancient carbonate muds are source of
    the significant petroleum reserves of Arabian
    Gulf region
  • The present is the key to the past!

8
Structural Provinces - Arabian Gulf
Zagros Fold Mts
Pre-Cambrian Shield
Mesozoic to Tertiary Foreland Basin
4,000 meters of Mesozoic to Tertiary Sediment
sequestered in Foreland Basin!
NASA Image
9
Analysis of Crude Oils find Alkanes Isoprenoids
  • The alkane/acyclic isoprenoid fraction is the
    main constituent of most crude oils
  • A large number of crude oils and rock extracts
    from Timan-Pechora basin (Russia) suggest this
    fraction is direct product of liquefaction of
    biological debris preserved essentially unaltered
    till oil generation.
  • Result is the primary biological provenance of
    this fraction is preserved in the oil fraction.

10
Hydrocarbon Source
  • Collister, Ehrlich, Mango, Johnson (AAPG,
    2004) propose primary organic materials convert
    to oil as dispersed alkanes isoprenoids in
    rocks
  • Low TOC source or undermature rocks generate
    significant oil if source carries sufficient
    special kerogen derived from biological membranes
    is unchanged till liquefaction
  • Observations experiments, mostly French labs,
    show resistant organic membranes in form of
    biopolymers play this role.
  • Stable over a large range of conditions, survive
    early secondary bacterial attack late-stage
    breakdown with increasing thermal stress.

11
Evidence
  • Significant Holocene accumulations of
    cyanobacteria lime mud in Arabian Gulf axis
    tidal zones
  • These sediments have source rocks potential
  • Similar sediments have accumulated since Triassic
  • Ancient carbonate muds are source of significant
    petroleum reserves of Arabian Gulf region
  • The present is the key to the past!

12
Carbonate Provinces - Arabian Gulf
Basin
Ramp
Open Shelf
Restricted Shelf
13
Dust and Whiting response
Satellite scenes SW, to West coast of Arabian
Gulf 12 July 2006, MODIS Rapid Response system
site, Nasa http//rapidfire.sci.gsfc.nasa.gov
14
Weather Station Data
Temperatures - pink MPH windspeed -
black. Windspeeds over 25mph coincide with
regional "Whiting" blooms.
15
Arabian Gulf Factory producing carbonates
storing products of cyanobacteria since Permian
NASA Image
16
A big day for a bloom!!
Organics in the Gulf!
Nasa Image
17
Whitings common to-day and common back in the
Triassic!
Organics in the Gulf!
Nasa Image
18
Wells and Illling - 1965
  • Among 1st to report Whitings offshore from
    Qatar precipitated in Persian Gulf.
  • Ascribed whitings to CO2 removal by
    photosynthesis of phytoplankton.
  • Groot (1964) lab analysis of suspended sediment
    offshore was 70 Aragonite, 10 Calcite, 15 Mg
    Calcite, 5 Quartz 5 Dolomites.
  • Lab experiments used NaCO3 to remove CO2 pptated
    aragonite from Gulf, but rates did not match
    instantaneous formation of Whitings but took 2
    to three weeks.

19
Local Whiting Occurrences!
NASA satellite scene with very localized
diminished Whitings off UAE on Pearl Bank,
offshore East Qatar, north flank of Bahrain
shoal, and offshore from Saudi/Kuwaiti border
20
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21
Persian Gulf Facies Distribution
After Wilkinson Drummond, 2004
22
Persian Gulf Mud Distribution
After Wilkinson Drummond, 2004
23
Lime Mud Sequestered in Basin Axis Tidal Flats
The mud probably forms less than 1 of sediment
signal since Mesozoic but forms a formidable
source for hydrocarbons of Gulf
24
Facies of UAE
Lime muds organics sequestered in axial
trough tidal flats
Axial Muds
Skeletal Sands
Ooid Tidal Deltas
Reefs Coralgal Sands
Pellets Grapestones
Coastal Sabkha
Cyanobacterial mats
25
Lime mud organics sequestered in
Mangrove swamp tidal flats
26
Shoaling Upward Inner Shelf Cycle
Shoaling Up Cycle
27
Abu Dhabi Mud Flats
28
Abu Dhabi Mud Flats
29
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30
High Intertidal Cyanobacterial Flats
Intertidal Carbonate Flats
Earlier High Energy Beaches
Supratidal Sabkha Evaporites
31


32
Tidal Ponds
Tidal Creek
33
Tidal Pond
Tidal Creek Cyanobacterial Megapoygons
34
Cyanobacterial Peat
35
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36
Crinkled Algal Mat
Gypsum Mush
Cyanobacterial Peat
37
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38
SURFACE ANHYDRITE POLYGONS
39
Anhydrite
Cyanobacterial Peat
Intertidal Muds
40
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41
HALITE POLYGONS
42
Washover Sediments
Anhydrite
Cyanobacterial Peat
43
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44
MICROTOME OF CYANOBACTERIAL MATS
45
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46
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47
Modern Sources of lime mud
  • Isolated seas Arabian Gulf
  • Wide platforms in nutrient deserts of tropical
    seas Bahamas

48
Bahamian Organic Productivity
  • Whitings precipitate 1.35 metric tons per year
  • 25 of Whiting is organic matter mostly
    cyanobacteria and microalgae
  • As much as 1.6 of surface sediment may contain
    organic matter
  • Subsurface sediments preserve 1 TOC (up to 4)
  • 7Be (half-life 53 days) found in Whitings but
    absent in resuspended bottom sediment

49
Bahamas Ocean Drilling Transect
Kramer, Swart, DeCarlo Schosvbo, 2005
50
Modern Sources of lime mud
  • Isolated seas Arabian Gulf
  • Wide platforms in nutrient deserts of tropical
    seas Bahamas

51
Whitings
52
Whiting
53
Aragonite Needles 2.5mm Long 0.25 mm Wide
54
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55
Sequestration in Downslope wedge
56
Sequestration on Tidal Flat
57
Bahamas shoals source of mud
58
Rates of Accumulation
  • Short-lived isotopes determin accumulation rates
    (Shinn et al., 2000).
  • Samples analyzed within 20 days of collection
    using high-resolution gamma ray spectrometer for
    short-lived isotopes Be-7 Th-234 with
    respective half lives of approx. 53 23 days.
  • Active billowing Whitings had Be-7 Th 234 but
    bottom sediment depleted.
  • None of bottom sediment stirred by storms
    contained short-lived isotopes.
  • Radiogenic elements adsorbed on sediment surface,
    or if epitaxial growth occurred, these
    short-lived isotopes would be present.

59
Bahamian Whitings Instant Precipitates
  • Whitings vivid white while water outside them is
    clear!
  • Instantaneous chemical /or biochemical aragonite
    precipitates.
  • Many Whitings drift back forth with tides over
    time continually raining sediment to bottom with
    no documented dispersal or end.
  • Wane in intensity at slack tide to strengthen
    when tide reverses.
  • Cloud (1961) followed a single Whiting for 48
    hours while Shinn et al. (1989) followed Whitings
    for 24 hrs.
  • Some persisted for 24 hrs over hard pellet sands
    with no mud stirred into suspension. Shinn et al.
    (1989) returned to same Whitings still drifting
    over pellet sand 2 days later Robbins et al.
    (1997) documented persistence from satellite
    images.
  • Artificial Whitings of stirred up bottom settled
    within 6 hours
  • Nearby natural Whitings persisted and did not
    dissipate
  • Whiting water pumped to settling tanks aboard
    boat settled in 6 hrs.

60
Whiting Mud Sequestration
  • Hurricanes winter storms export vast quantities
    of lime mud over bank edge.
  • 7 weeks after Hurricane Andrew (1992), lime mud
    collected as layers up to 5 cm thick over shallow
    ooid sands near bank edge (Shinn et al., 1993).
    Layers from slurries of lime mud exiting bank to
    Florida Straits Tongue of Ocean.
  • An up to 90m thick wedge of Holocene sediment at
    base of Bahama Bank slope (Wilber et al.,1990)
    represents 40 to 80 by volume of mud presently
    sequestered for entire bank.
  • Vertical and lateral progradation rate of wedge
    is 11-15 m/ka and 80-110 m/ka, respectively
    (Wilber et al., 1990). Measures amount
    accumulated during last 6-8 ka and does not
    consider Whiting mud carried northward in Gulf
    Stream to distant locations and/or to
    dissolution.
  • Ball et al. (1967) and Perkins and Enos (1968)
    report significant off-bank sediment transport in
    Florida following Hurricanes Donna and Betsy.
    Similar observations made and photographed in
    Florida by Shinn following Hurricane Andrew in
    1992.
  • Lime mud-laden sediment continues to spill off
    the platform for weeks following a hurricane.
    The Bahamian Bank has been submerged for the past
    6-8 ka and is affected by a hurricane every 6 to
    10 years. Overproduction, possibly far greater
    than 280, is necessary to account for what is
    presently on the bank.

61
Organic Matter
  • Phytoplankton nucleae are cores to cells
  • Viable phytoplankton cyanobacterial cells in
    Whitings not observed in bottom sediment -
    deteriorate quickly after deposition (Robbins and
    Blackwelder, 1992) .
  • Aragonite needles adher to surface of living
    planktonic cyanobacteria indicates rapid
    precipitation within water column (Robbins
    Blackwelder, 1992 Yates Robbins, 1998 1999
    2001).
  • 25 of the 1.3 million metric tons ppted
    suspended each year in Bahamas is organic matter,
    dropping to 1.8 of surface sediment. .
  • Bahamian Bank Whitings associated organic
    matter cover more limited areas swept off bank
    into deep water. Cores through Neogene western
    platform slope sediments preserve 1 TOC up to 4
    (Kramer, Swart.

62
Bahamas Morphology
Rim
Basin
Restricted Shelf
Open Shelf
63
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64
Carbonate Mud Settings
  • Carbonate muds common through earth history
  • Carbonates signaled by thick sections adjacent to
    margins of recently pulled apart continental
    plates /or in compressional terrains of
    colliding margins
  • Carbonate muds collect in
  • Lower portions of updip shallow water cycles
  • Lower portions of downdip restricted basins
    basin slopes

65
Organic matter lt1 weight of Holocene tidal
flats axial trough !
66
Carbonate Mud Accumulation Sites of Ancient
Arabian
  • Late Paleozoic to Early Mesozoic behind
    Structural Depositional Barriers
  • Punctuated by limited access to sea repeated
    arid climatic events favoring cyanobacterial
    preservation
  • Now trapped beneath Arabian Gulf

67
Hydrocarbon Source, Seal, Reservoir
  • Source Rocks
  • Permian Khuff - Saudi Arabia
  • Lw Jurassic Tuwaiq Mt. Group - Saudi Arabia
  • Lw Cretaceous Maudud Fm. of UAE
  • Seals
  • Usually with playa and sabkha evaporites
  • Reservoirs
  • Deep Ghawar
  • Berri, Ghawar
  • Zakum Field, UAE Thamama I, II, and III, Shaybah
  • Mishrif
  • Asmari

68
Arabian Gulf Basin
  • Traces complex history of plate tectonic
    sedimentary fill
  • Pre Cambrian to Infra-Cambrian - Continental
    interior
  • Silurian and Ordovician clastics Continental
    interior
  • Permian clastics carbonates Trailing margin
  • Upper Jurassic carbonates Trailing margin
  • Lower Cretaceous carbonates Trailing margin
  • Middle Cretaceous Compression Zagros Mts
    initiated
  • Tertiary carbonates clastics - Compressional
    margin

69
Evolution of Arabian Gulf
Foreland Basin
Compression Foreland Basin
Extensional margin
Extensional margin
Interior Sag
After Kingston et al, 1983
70
Hydrocarbon Production in Arabian
plate Stratigraphic section - Section
represents approx 2,438.5m in 200
my - Accumulation Rate 1.22 mm per 1 Ky
71
Lime Source
PERMIAN KHUFF FM DEPOSITIONAL SETTNG (Al-Jallal,
1995)
72
Restricted Entrance To Sea
Structural Depositional Barrier over Hercynian
Horst Blocks
Permian Khuff Saudi Arabia Oman UAE
Arid Tropics Air System
Wide Shadow from Adjacent Continents
73
WORLDS SOURCE ROCKS
Carbonate Mud Source Rocks
After Baum, Kendall
74
Geological Setting of Jurassic Oil
Seal
Seal
Reservoir
Reservoir
IntrashelfBasin
IntrashelfBasin
75
Lime Source
GOTNIAN DEPOSITIONAL SETTING (Al-Sharhan
Kendall, 1986)
76
Lime Source
77
Restricted Entrance To Sea
Upper Jurassic Saudi Arabia Kuwait, Iran UAE
Depositional Barrier over Hercynian Horst Blocks
Tropical Air System !
Wide Shadow from Adjacent Continents
78
After Dennis Tassa
79
Zagros Fold Mountains - Iran
NASA Image
80
Lower Cretaceous
Stratigraphic cross-section of Cretaceous
Eastern Arabia (Alsharhan Nairn 1986)
81
Tertiary
Lime Source
Stratigraphic cross-section of Neogene Arabian
Gulf (Alsharhan Nairn 1986)
82
From International Petroleum Encyclopedia
Lime Source
83
ORGANIC MATTER HYPOTHESIS
  • The Arabian Gulf a sink of organic matter since
    Triassic
  • As with modern Gulf much of this organic matter
    related to multiple organic blooms through
    geological time
  • Organic matter trapped in intertidal flat
    basinal muds
  • Dispersed organic matter in form of biological
    membranes, have simple chemical composition
    structure, so liquefy at a threshold
    temperature do not require time temperature
    history for maturation.
  • A burst of oil generation produces transient
    overpressures resulting in liberation of oil by
    microfracturing and long-range migration through
    the resulting fractures.
  • This ensures that large volumes of oil could be
    generated over a short time.

84
CONCLUSIONS
  • Arabian Gulf Holocene cyanobacteria mud
    accumulations significant in axis tidal zones
  • These sediments have source rocks potential
  • Similar sediments accumulated since Triassic
  • These ancient carbonate muds are source of the
    significant petroleum reserves of Arabian Gulf
    region
  • The present is the key to the past!

85
Now to lunch!
86
West of Dhabaiya Mangrove Swamp
Holocene tidal flats are sequestering gt1 of
weight as organic matter!
87
Bahamas -Deep water of marginal zone-Shallow t
idal flats
88
Bahamas
89
Bahamas-Mud transportedby hurricanessettle
in highenergychannels
90
Bahamas Shoals are a source of mud!
91
Bahamas shoals source of mud
92
Bahamas shoals source of mud
93
Bahamas shoals source of mud
94
Bahamas shoals source of mud
95
Bahamas shoals source of mud
96
Bahamas shoals source of mud
97
Bahamas shoals source of mud
98
Bahamas shoals source of mud
99
Bahamas shoals source of mud
100
Appalachians Ordovician Isolated Foreland Basin
101
AppalachiansOrdovician
102
Appalachians - Ordovician
103
Appalachians - Ordovician
104
Appalachians - Ordovician
105
Appalachians - Ordovician
106
Appalachians - Ordovician
107
Appalachians Ordovician
108
Appalachians - Ordovician
109
Appalachians - Ordovician
deepening up from grains to mud
110
Appalachians - Ordovician
111
Appalachians Ordovician
112
Murray Basin
113
Murray Basin
114
Lime muds organics sequestered in axial
trough tidal flats
Ooid Tidal Deltas
Skeletal Sands
Reefs Coralgal Sands
Pellets Grapestones
Coastal Sabkha
Cyanobacterial mats
Cyanobacterial mats
115
Lime mud organics sequestered in
Mangrove swamp tidal flats
116
Intertidal Sand Mud Flats
Tidal Channels
Hardgrounds
Beach Ridges
Cyanobacterial Mats
Sabkha
117
Whitings
118
Geologic Cross-Section - Arabian Gulf
119
Lime Source
Gas
Paleozoic Stratigraphic Column Arabia
Gas
120
Jurassic Formations of Arabia
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