TOTAL EARTH SOLUTIONS OIL AND GAS SERVICES

Brett Johnson
Brett JohnsonSpecialist Management Consultant at um Imagemaps Pte Ltd
Innovate │Integrate │ Enhance │ Excel
Introduction to
Total Earth Solutions (TES)
TES - Services avaibale to the
Oil and Gas Industry
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Total Earth Solutions – Company Profile:
• Total Earth Solutions Pty Ltd (TES) is a specialist aviation,
geological, geophysical and geospatial consulting firm providing
services to the petroleum and mining industries.
• TES provides a range of technical services related to the
acquisition, processing and interpretation of geoscientific and
geospatial data collected from space, aircraft, UAV’s and ground
vehicles.
• We aim to offer a complete turnkey service where we can plan
and manage surveys all the way through to interpreting the data
to create highly detailed analyses of petroleum basins and
mining regions.
• We differentiate ourselves by employing a strong focus on the
geological interpretation of geophysical and geospatial data, but
also by having enormous experience in the effective and safe
management of airborne and ground survey operations.
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Total Earth Solutions – Services (1):
• Aviation
• TES has qualified commercial pilots on its staff, with years of experience in low level survey operations around the world.
• Qualified safety auditor.
• Sourcing of survey aircraft.
• Sourcing of survey pilots.
• Development of aviation procedures and management of compliance.
• Provision of survey equipment including – magnetic, radiometric, gravity, LIDAR, aerial photography.
• Construction and installation of survey systems.
• Planning and management of airborne operations.
• UAV
• TES is at the forefront of development and utilisation of Unmanned Aerial Vehicles (UAV’s) carrying hi-tech payloads such as
LIDAR, thermal imaging and geophysical systems, applied to exploration, development, infrastructure mapping and monitoring.
• Data Collection
• TES can identify, source and interpret the best data for the issue at hand. We have enormous experience in data acquired from a
range of platforms, from satellites, aircraft, UAVs, ships through to ground acquisition. We can examine the problem and develop
the most cost effective combination of data to meet the needs of the client.
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Total Earth Solutions – Services (2):
• Geophysical Interpretation and Modelling
• TES are expert in detailed geological interpretation of geophysical and geospatial data:
• Definition of broad basin geometry in regions with limited and/or poor quality seismic data.
• Basement and intra-basin structural interpretation utilizing airborne and ground geophysical
data, remote sensing and seismic data.
• Geophysical target identification , assessment and modelling.
• 3D depth to basement modelling utilizing magnetic and gravity methods, constrained by seismic
and well data.
• Field mapping and structural interpretation, integrating classical structural analyses with
interpretation of available geophysical and spectral datasets.
• Testing and validation of seismic interpretations through integration with potential field data.
• Geophysical survey design for airborne magnetic and gravity data acquisition.
• Geophysical data processing, imaging and modelling including magnetic and gravity datasets.
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• Dr Warick Crowe, BSc(hons), MSc, PhD – geology, airborne
geophysics, interpretation
• Dr Crowe is a globally recognised expert in structural
geology and the interpretation of airborne geophysical
data. Dr Crowe was for some years the principal
interpretation geologist for the world’s largest airborne
geophysical company (Fugro) conducting major
interpretation projects around the world.
Total Earth Solutions – Bios:
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• Brad George, BSc (hons) MBA. – geophysics, geology,
survey management, mineral exploration, business
management, investment banking/capital raising.
• A geophysicist/geologist with extensive management
training and experience.
• Extensive background in ground and airborne geophysical
survey operations.
• Experience in all facets of the mining industry from
exploration, operations, management.
• Investment banking and mining financial analysis.
Total Earth Solutions – Bios:
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• Brett Johnson (MBA). Aviation operations, geophysical
survey, geospatial survey,
• A qualified pilot and safety auditor, Brett has over 15 years
of airborne geophysical and geospatial experience,
including being aviation and operations manager for
several of the world’s largest and most sophisticated
airborne survey companies. Brett has been personally
responsible for airborne surveys that have collected over
10 million km of geophysical and geospatial data around
the world.
Total Earth Solutions – Bios:
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• Geoff Peters BSc (hons) – geology/geophysics, survey
management, GIS
• A geophysicist with over 13 years’ experience in the collection,
processing and interpretation of ground and airborne
geophysical surveys for mineral and petroleum exploration.
• Strong geophysical modelling skills in the areas of magnetic,
gravity and electromagnetic geophysical techniques,
• Strong GIS skills allow the integration of a wide variety of
constraints, including geological data, and other available
geophysical data into the 3D and 2D model workspace to
provide more geologically realistic outcomes.
Total Earth Solutions – Bios:
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• Laurel Borromei, Masters in Strategic Procurement -
procurement, tender management, compliance
• Laurel is an expert in procurement and contract
management. Laurel has over 20 years’ experience of high
level procurement and contract management, having held
senior roles within major corporations such as Accenture,
Alcoa, Rio Tinto and Boral. Laurel has managed the
tendering and procurement process on numerous service
and capital projects with values in excess of $100m.
Total Earth Solutions – Bios:
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• Neil Dyer, PhD Bsc. Geophysics, Environmental Science,
• 24 years in the upstream oil and gas industry. Strong
technical background and knowledge of oil and gas
exploration geophysical techniques including gravity,
magnetic and seismic data acquisition, QC, processing and
interpretation
• VP and CTO experience in roles with direct technical input
into corporate strategies as well as managerial and
commercial responsibilities.
• Strong focus on technical evaluation, assimilation, adoption
and development of new ideas and technologies that add
value to the bottom line.
Total Earth Solutions – (Partners) Bio:
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• Total Earth Solutions carries out geophysical modelling using a variety of magnetic, gravity and
electromagnetic datasets.
• Geophysical modelling focuses on the physical properties of the subsurface rocks such as:
– Magnetic Susceptibility – The capacity for a material to become magnetised within the presence of the Earth’s
main magnetic field. The magnetisation direction is parallel to the Earth’s magnetic field in that location. This is
largely related to the presence of magnetic minerals such as magnetite.
– Remanent Magnetisation – When a material is magnetised permanently in a direction aligned with bedding,
laminations or other anisotropic structures. The magnetisation direction may oppose the Earths main field to
produce unusual negative anomalies.
– Density – Rocks have variable density or in other terms, mass per unit volume. For example, a basalt would typically
display a density of 3 grams per cubic centimetre while a quartzite would typically display a density of 2.67 grams
per cubic centimetre.
– Conductivity – The capacity of a material to conduct an electric current. In Electromagnetic surveys, this current is
induced through an artificially generated electromagnetic field. Certain sulphide minerals, graphite, shale and salty
groundwater horizons display a high conductivity, while unweathered, non-porous bedrock displays low
conductivity.
• The key point is that geophysical modelling relies on a contrast in physical properties between the
target of interest and the surround rock such as:
– A density contrast: A low density salt dome in a more dense sedimentary host rock
– A magnetic susceptibility contrast: A magnetically susceptible dolerite dyke in a magnetically quiet granite host rock
– A conductivity contrast: A conductive sulphide vein in a resistive bedrock host
Total Earth Solutions: Capabilities
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• The basin margins
• Basin symmetry/asymmetry
• Depocentres/Thickness of Sedimentary Packages/Depth to
basement
• Base of major stratigraphic units
• Intrabasin volcanics
• Basin Involved Structures
What is Basin Architecture? – 2D Seismic Example
• Intra-basin faults
• Basin History (Inversion?)
• Major Salt structures
• Seismic data is the benchmark for basin architecture studies,
particularly in resolving structures at depth
• Seismic is very expensive – what are the alternatives?
*From: Carr et al STRUCTURAL AND STRATIGRAPHIC ARCHITECTURE OF WESTERN AUSTRALIA’S FRONTIER ONSHORE SEDIMENTARY BASINS: THE WESTERN OFFICER AND
SOUTHERN CARNARVON BASINS
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TES Basin Architecture – Potential Fields Approach
Overview
*From: Carr et al STRUCTURAL AND STRATIGRAPHIC ARCHITECTURE OF WESTERN AUSTRALIA’S FRONTIER ONSHORE SEDIMENTARY BASINS: THE WESTERN OFFICER AND
SOUTHERN CARNARVON BASINS
1. Definition of broad basin geometry
in regions with limited and/or poor
quality seismic data.
2. Basement and intra-basin
structural interpretation.
3. Depth to basement modelling
utilizing magnetic and gravity
methods.
4. Defining basin architectural models
through the integrated analyses of
basement geometry and structure
with the intra-basin structural
configuration of sedimentary
basins.
• Interpretation team includes tectonic,
regional and prospect geologists that
understand geophysics intimately and
the integration of those data with
packages such as Kingdom, we
understand the language of Oil and
Gas explorers
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First level text heading
• Second level text with bullets
– Third level text with bullets
• Fourth level text with bullets
– Fifth level text with bullets
Traditional role of Aeromagnetics in
Seismic Exploration – Only use it when you can’t do
seismic?; Coarse Scale Reconnaisaance and Structure?
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What else can you get from magnetic data?
Magnetic Signal variation from a range of Depths
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Qualitative Interpretation of Magnetic Data:
Basin Architecture: Basin Margins, Sub basins
• Perth Basin (Onshore Part) –
magnetic response; Eastern edge of
basin well defined;
• Sub basin area margins including
lows (troughs) and highs (terraces)
are only weakly correlated with
magnetic response
• Some deep magnetic basement
responses
• Defining Intra-basin Structures and
depth to basement with magnetic
data depends on the magnetic
mineral content – not always
possible
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Qualitative Interpretation of Magnetic Data:
Basin Architecture: Salt Rupture Zones in the Officer Basin
• Browne Salt Wall has
breached the flat lying
magnetic Table Hill
Volcanics
• “Breached” zone
obvious in 1VD
magnetic data
• Strike slip offsets – i.e.
intra-basin Structures,
are visible in the salt
wall magnetic response
• This could provide the
means to target further
seismic surveys (salt wall
= possible hydrocarbon
trap)
• Deep basement
magnetic sources are
also visible
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Qualitative Interpretation of Magnetic Data:
Basin Architecture: Salt Rupture Zones in the Officer Basin
• Browne Salt Wall has
breached the flat lying
magnetic Table Hill
Volcanics
• “Breached” zone
obvious in 1VD
magnetic data
• Strike slip offsets – i.e.
intra-basin Structures,
are visible in the salt
wall magnetic response
• This could provide the
means to target further
seismic surveys (salt wall
= possible hydrocarbon
trap)
• Deep basement
magnetic sources are
also visible
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Comparison of Seismic Data with Aeromagnetic
data: Salt Rupture Zones in the Officer Basin
Subtle first vertical derivative (1VD) Magnetic
signature from breached Table Hill Volcanics
Salt diapirs are generally well imaged in Seismic reflection Data
In this case the Browne Salt Wall can be seen in the magnetic data because it has
breached a sub horizontal magnetic layer (Table Hill Volcanics)
Browne
Salt Wall
Table Hill Volcanics
Salt
wall?
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Officer Basin Salt Walls – Gravity and Gradient
Gravity Response of Forward Model (1)
Gzz
Gz
[Gz]
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Officer Basin Salt Walls – Gravity and Gradient
Gravity Response of Forward Model (2)
Gzz
Gz
[Gz]
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Officer Basin Salt Walls – Gravity and Gradient
Gravity Response of Forward Model (3)
Gzz
Gz
[Gz]
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Officer Basin Salt Walls – Gravity and Gradient
Gravity Response of Forward Model (4)
Gzz
Gz
[Gz]
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Officer Basin Salt Walls – Gravity and Gradient
Gravity Response of Forward Model (5)
2.8 g/cc
2.6 g/cc
2.5 g/cc
2.35 g/cc
Gzz
Gz
[Gz]
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Basin Architecture from Aeromagnetic Data –
Sedminentary Layer Sequence Mapping in the
Canning/Amadeus Basins
• Magnetic signal
from shallow to
deep sources
• Surficial Dendritic
drainage patterns
• Subtle magnetic
signatures from
relatively shallow
siltstones,
sandstones,
carbonates and
conglomerates
layers containing
minor magnetite
• Deep, long
wavelength
signals from
basement sources
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Basin Architecture from Aeromagnetic Data –
Sedminentary Layer Sequence Mapping in the
Canning/Amadeus Basins
• Magnetic signal
from shallow to
deep sources
• Surficial Dendritic
drainage patterns
• Subtle magnetic
signatures from
relatively shallow
siltstones,
sandstones,
carbonates and
conglomerates
layers containing
minor magnetite
• Deep, long
wavelength
signals from
basement sources
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DTB – Magnetic Methods – Forward Modelling
• A magnetic basement below
non-magnetic basin fill
• Strong magnetic response at
basin edges
• Less “intuitive” to model than
gravity data in the case of
deep basins (anomaly shape
more complex)
• Magnetic response of shallow
or flat-lying “intra-basin”
magnetic units (i.e. volcanics)
is very ambiguous to model
• Steep dipping dykes or
contacts can be modelled
more accurately than shallow
or flat-lying bodies
• Magnetic susceptibility (model
property) can be variable
across orders of magnitude
even in the one geological unit
Subtle magnetic response of
shallow dipping unit
Intra-basin Volcanics
Strong response of basin edge
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Qualitative Basin Architecture:
Gravity Data – Basin Margins, Sub basins
Perth Basin – magnetic response; Eastern
edge of basin well defined; Basin lows
(troughs) and highs (terraces) weakly
correlated with magnetic response
Perth Basin – Gravity response; Eastern edge
of basin well defined; Basin lows (troughs)
and highs (terraces) generally well
correlated with gravity response
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DTB – Gravity Methods – Forward Modelling 2
3.0 g/cc
2.65 g/cc
2.6 g/cc
2.5 g/cc
2.2 g/cc
Density Contrast Basin/Basement 0.35 g/cc
Faults interpreted
from other data
Thinning basin sediments
modelled to fit increasing
gravity response
Drill hole with downhole density
measurements and lithology
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DTB – Euler Methods 1
• Euler Deconvolution is a semi automated depth to source method that can be used with gravity
or magnetic data
• The process uses “windows” of a user specified size (number of cells or data points) that move
the across the data in 2D or 3D. Large windows are suited to deep targets, small windows to
shallow targets.
• At each window location a depth solution is calculated with depth “Z” below surface and window
offset X (2D) or X,Y (3D) with respect to the window centre
• Statistics calculated for each depth solution, such as depth uncertainty and horizontal
uncertainty, are used to filer the solutions at a later stage
• The depth solutions can be calculated for different structural indices (SI) that relate to the type of
structure/geological features that are expected in the area and the method used (magnetics or
gravity). A high structural index (SI) indicates that the gravity/magnetic response drops off more
rapidly with depth
SI Magnetic Field Gravity Field
0Contact Sill/Dyke/Step
0.5Thick Step Ribbon
1Sill/Dyke Pipe
2Pipe Sphere
3Sphere n/a
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DTB – Euler Methods 2
First Vertical Derivative
First Horizontal Derivative
Vertical Gravity Component
Euler Solution Window
(7 data points) moves
along profile (2D) and
solves for x,z (2D)
location of source body
with user specified SI
Spherical Source Body
SI (Gravity) = 2
SI (Magnetics) = 3
Horizontal Offset (with
respect to window
centre)
Depth
Window Centre
Note that this window
size is well suited for
the target SI, size, and
depth
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DTB – Euler Methods 3
• Euler Deconvolution produces a vast amount of solutions most of which are spurious
• A window that is too small relative to the source size/depth will not capture the full
wavelength of the anomaly and the depth solution will be inaccurate
• With large window sizes, interference from neighbouring source bodies, or multiple
source bodies in a single “window” will produce poor depth estimates
• Generally it is easiest to calculate solutions for all SI, followed by filtering
• Basic statistical filtering (depth uncertainty, horizontal uncertainty etc.) is generally
not adequate
• Some Geological input is required to determine which SI solution set is best suited for
each geological body (dykes, sills, intrusions etc.)
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DTB – Gravity Euler Methods 1
• Accurate calculated derivatives of potential fields require the original
field to be sampled at a line or station spacing less than or equal to
the depth of the source bodies of interest
• Vertical and horizontal derivatives from wide, variably spaced gravity
data are noisy and contain point aliasing around stations
• As Euler depth solutions require horizontal and vertical derivatives as
inputs to the calculations, they are not well suited to widely spaced
gravity data
• The noise introduced into the derivatives can lead to spurious
solutions
• Careful low pass or upward continuation can be used to minimise
these affects, so that the data may still be used to calculate Euler
Solutions for very long wavelength (deep) features at the expense of
shallow features
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DTB – Gravity Euler Methods 2
Noisy First vertical derivative of widely spaced gravity data
“Pimple” derivative artefacts from single gravity stations
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DTB – Magnetic Euler Methods 1
Deep Basin
Moderately Deep Mafic/Ultramafic
Strongly Magnetic Edge
Of Basin
Shallow Granite Body
Shallow Dykes
Example – Capricorn Basin – A variety of source bodies that will require different SI and window
sizes
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DTB – Magnetic Euler Methods 2
Deep Basin
Structural Index (SI) = 0; Tightly clustered, generally consistent depth solutions over the deep
basin area; poor definition of dykes in South West
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DTB – Magnetic Euler Methods 3
Shallow Dykes
Strongly Magnetic Edge
Of Basin
Structural Index (SI) = 1; Tightly clustered, consistent solutions over the shallow dykes
and basin edges; scattered and inconsistent in deep basin area
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DTB – Magnetic Euler Methods 4
• One approach is to digitize and classify the main magnetic
features into SI units
SI=1 SI=0
SI=1
SI=1
SI=1 SI=1
SI=1
SI=0
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DTB – Magnetic Euler Methods 5
• The resultant depth to basement surface shows a deep
basin in the east, with some near surface magnetic bodies
superimposed
• Further processing could include the removal of the
shallow magnetic features to produce a more smooth and
coherent DTB surface
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DTB – Gravity Methods 2
Perth Basin – magnetic response; Eastern
edge of basin well defined; Basin lows
(troughs) and highs (terraces) weakly
correlated with magnetic response
Perth Basin – Gravity response; Eastern edge
of basin well defined; Basin lows (troughs)
and highs (terraces) generally well
correlated with gravity response
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Airborne Gravity Vs Gravity Gradiometry
• Gravity
• 1 milliGal = 1 mGal = 10-3
Gal
• The average gravitational
accelerationg ~ 9.8 m/s2 =
980 Gal ≈ 106 mGal
• Gravity Gradiometry
• 1 E = 10-9 s-2
= 0.1 mGal/km
= 10-4 mGal/m
• The average vertical
gravity gradient
Tzz ~ 0.3086 mGal/m =
3086 E
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Airborne Gravity Vs Gravity Gradiometry
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Airborne Gravity Vs Gravity Gradiometry “System
Noise”
• Signal to noise ratios of Airborne
gravity (Gravity gz) and airborne
gravity gradiometry (Gzz) across
bandwidth 0.001 to approx 2Hz
• Using a fixed acquisition speed of
60ms-1 this can be related to the
wavelength of anomalies, i.e. the
depth to the sources of interest
• According to this graph, at this
acquisition speed the Gravity gz is
superior at wavelengths greater
than 30km
• The Gzz is superior at wavelengths
shorter than 30km
• This “crossover” point is still hotly
debated
• Measures can be taken to improve
Gravity gz
*From Arkex US patent 20140081595
A1
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Airborne Gravity Vs Gravity Gradiometry source
depth versus signal energy distribution
• Consider a monopole point source
100m below surface (i.e. a source
where the depth of burial is much
greater than the width of the
source)
• In terms of the Gz (gravity)
response most of the energy is
concentrated at wavelengths 4x
depth of burial (i.e. 1000m depth
= 4000m wavelength)
• What depths of burial are
important for O&G exploration?
• What wavelengths are important
for O&G exploration?
• What system is adequate and
what system is in excess of the
required resolution?
*After Dransfield Et Al,
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Airborne Gravity Vs Gravity Gradiometry: Improving
Airborne Gravity through Noise Reduction
• The noise in airborne gravity
systems is reduced via filtering
• The filters are specified by the
length of time over which the
filter operates
• Longer filters reduce noise and
resolution at a given
acquisition speed
• Minimum ½ sine wave
resolution = ½ (acquisition
speed (ms-1) x filter length)
• Noise can also be reduced by
averaging lines (where line
spacing is less than the along
line filter length)
• Clients can tailor the line
spacing/acquisition
speed/filter length to suit their
requirements
*After Olsen 2010
* From Sanders AirGrav
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Airborne Gravity Vs Gravity Gradiometry near
surface sources
• Gravity gradiometry systems are
very sensitive to near surface
sources
• Gravity systems are more
sensitive to deeper sources
• The response of shallow
sources in gravity gradient data
can obscure deeper sources
*After Olsen 2010
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Airborne Gravity Vs Gravity Gradiometry – Basin
Model
Gzz
Gz
Salt dome
apparent in
both Gzz
and Gz
Near surface palaeo-
channel and minor ridge
causes strong response in
Gzz
Basement Offset
(masked by
adjacent
basement density
variation)
Intrabasin offset
(masked by
nearby salt
dome) Mafic Basement and
dyke/sills (larger relative
amplitude in Gz)
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Airborne Gravity Vs Gravity Gradiometry – Basin
Model – With noise added
5 Eotvos RMS noise (400m cutoff)
0.2 mGal RMS noise (grey)
1 mGal RMS noise (grey dashed
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Airborne Gravity Vs Gravity Gradiometry – Basin
Model
Gzz
Gz
Salt dome
apparent in
both Gzz
and Gz
Near surface palaeo-
channel and minor ridge
causes strong response in
Gzz
Basement Offset
(masked by
adjacent
basement density
variation)
Intrabasin offset
(masked by
nearby salt
dome) Mafic Basement and
dyke/sills (larger relative
amplitude in Gz)
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Forward Modelling the Gz and Gzz response of a
basement shelf interpreted from Seismic Data
• An interpreted 2D
seismic section
was used to
construct a
basement model
• The Gz and Gzz
reponse of the
model was
calculated to
determine the
most
appropriaate
system
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Forward Modelling the Gz and Gzz response of a
basement shelf interpreted from Seismic Data
• The depth of the
shelf is
approximately
2000m
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Forward Modelling the Gz and Gzz response of a
basement shelf interpreted from Seismic Data
• Gz response with
estimated system
noise added
• Gzz response with
system noise added
• Both resolve the
feature of interest
• Which one is more
cost effective?
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Forward Modelling the Gz and Gzz response of a
basement shelf interpreted from Seismic Data
• Gz response with
estimated system
noise added
• Gzz response with
system noise added
• Both resolve the
feature of interest
• Which one is more
cost effective?
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Example – Interpretation using available magnetic and
radiometric data, imagery and Legacy geological mapping
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Officer Basin: Browne RTP
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Officer Basin: Browne RTP 1VD
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Officer Basin: Browne RTP plus seismic interp
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Officer Basin: Browne RTP plus werner solutions
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Officer Basin: Browne THV plus mag interp
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Officer Basin: Browne Seismic Interp Map
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Officer Basin: Browne Basement Lithology Map
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Pre – Salt: How can potential fields add value
• Pre salt hydrocarbon exploration takes place at great depth
– Great depth:
• long source wavelengths Suitable for Airborne gravimetry
• Poorly imaged seismic data at depth or obscured by salt structures
– Shallow gravity gradiometry and magnetic data may assist with static
corrections to seismic data
– Airborne Magnetic data may provide DTB estimates (base of Pre-salt
formation)
– Constraint of potential field geophysical modelling through well data and
seismic sections
– Identification of Radial or sub paralell faults associated with active diapirs
– Identification of extensional structures that focus salt emplacement
– Interpolate structure between 2D seismic lines
– Estimates of salt thickness where seismic is poorly imaged, ie, based on the
calculated thickness below the top of the salt as imaged in the seismic data via
gravity modelling, and constrained with wells where possible
– Estimates of density to use in gravity models based on downhole tools
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TOTAL EARTH SOLUTIONS OIL AND GAS SERVICES

  • 1. Innovate │Integrate │ Enhance │ Excel Introduction to Total Earth Solutions (TES) TES - Services avaibale to the Oil and Gas Industry
  • 2. 2 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Total Earth Solutions – Company Profile: • Total Earth Solutions Pty Ltd (TES) is a specialist aviation, geological, geophysical and geospatial consulting firm providing services to the petroleum and mining industries. • TES provides a range of technical services related to the acquisition, processing and interpretation of geoscientific and geospatial data collected from space, aircraft, UAV’s and ground vehicles. • We aim to offer a complete turnkey service where we can plan and manage surveys all the way through to interpreting the data to create highly detailed analyses of petroleum basins and mining regions. • We differentiate ourselves by employing a strong focus on the geological interpretation of geophysical and geospatial data, but also by having enormous experience in the effective and safe management of airborne and ground survey operations.
  • 3. 3 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Total Earth Solutions – Services (1): • Aviation • TES has qualified commercial pilots on its staff, with years of experience in low level survey operations around the world. • Qualified safety auditor. • Sourcing of survey aircraft. • Sourcing of survey pilots. • Development of aviation procedures and management of compliance. • Provision of survey equipment including – magnetic, radiometric, gravity, LIDAR, aerial photography. • Construction and installation of survey systems. • Planning and management of airborne operations. • UAV • TES is at the forefront of development and utilisation of Unmanned Aerial Vehicles (UAV’s) carrying hi-tech payloads such as LIDAR, thermal imaging and geophysical systems, applied to exploration, development, infrastructure mapping and monitoring. • Data Collection • TES can identify, source and interpret the best data for the issue at hand. We have enormous experience in data acquired from a range of platforms, from satellites, aircraft, UAVs, ships through to ground acquisition. We can examine the problem and develop the most cost effective combination of data to meet the needs of the client.
  • 4. 4 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Total Earth Solutions – Services (2): • Geophysical Interpretation and Modelling • TES are expert in detailed geological interpretation of geophysical and geospatial data: • Definition of broad basin geometry in regions with limited and/or poor quality seismic data. • Basement and intra-basin structural interpretation utilizing airborne and ground geophysical data, remote sensing and seismic data. • Geophysical target identification , assessment and modelling. • 3D depth to basement modelling utilizing magnetic and gravity methods, constrained by seismic and well data. • Field mapping and structural interpretation, integrating classical structural analyses with interpretation of available geophysical and spectral datasets. • Testing and validation of seismic interpretations through integration with potential field data. • Geophysical survey design for airborne magnetic and gravity data acquisition. • Geophysical data processing, imaging and modelling including magnetic and gravity datasets.
  • 5. 5 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Dr Warick Crowe, BSc(hons), MSc, PhD – geology, airborne geophysics, interpretation • Dr Crowe is a globally recognised expert in structural geology and the interpretation of airborne geophysical data. Dr Crowe was for some years the principal interpretation geologist for the world’s largest airborne geophysical company (Fugro) conducting major interpretation projects around the world. Total Earth Solutions – Bios:
  • 6. 6 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Brad George, BSc (hons) MBA. – geophysics, geology, survey management, mineral exploration, business management, investment banking/capital raising. • A geophysicist/geologist with extensive management training and experience. • Extensive background in ground and airborne geophysical survey operations. • Experience in all facets of the mining industry from exploration, operations, management. • Investment banking and mining financial analysis. Total Earth Solutions – Bios:
  • 7. 7 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Brett Johnson (MBA). Aviation operations, geophysical survey, geospatial survey, • A qualified pilot and safety auditor, Brett has over 15 years of airborne geophysical and geospatial experience, including being aviation and operations manager for several of the world’s largest and most sophisticated airborne survey companies. Brett has been personally responsible for airborne surveys that have collected over 10 million km of geophysical and geospatial data around the world. Total Earth Solutions – Bios:
  • 8. 8 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Geoff Peters BSc (hons) – geology/geophysics, survey management, GIS • A geophysicist with over 13 years’ experience in the collection, processing and interpretation of ground and airborne geophysical surveys for mineral and petroleum exploration. • Strong geophysical modelling skills in the areas of magnetic, gravity and electromagnetic geophysical techniques, • Strong GIS skills allow the integration of a wide variety of constraints, including geological data, and other available geophysical data into the 3D and 2D model workspace to provide more geologically realistic outcomes. Total Earth Solutions – Bios:
  • 9. 9 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Laurel Borromei, Masters in Strategic Procurement - procurement, tender management, compliance • Laurel is an expert in procurement and contract management. Laurel has over 20 years’ experience of high level procurement and contract management, having held senior roles within major corporations such as Accenture, Alcoa, Rio Tinto and Boral. Laurel has managed the tendering and procurement process on numerous service and capital projects with values in excess of $100m. Total Earth Solutions – Bios:
  • 10. 10 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Neil Dyer, PhD Bsc. Geophysics, Environmental Science, • 24 years in the upstream oil and gas industry. Strong technical background and knowledge of oil and gas exploration geophysical techniques including gravity, magnetic and seismic data acquisition, QC, processing and interpretation • VP and CTO experience in roles with direct technical input into corporate strategies as well as managerial and commercial responsibilities. • Strong focus on technical evaluation, assimilation, adoption and development of new ideas and technologies that add value to the bottom line. Total Earth Solutions – (Partners) Bio:
  • 11. 11 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • Total Earth Solutions carries out geophysical modelling using a variety of magnetic, gravity and electromagnetic datasets. • Geophysical modelling focuses on the physical properties of the subsurface rocks such as: – Magnetic Susceptibility – The capacity for a material to become magnetised within the presence of the Earth’s main magnetic field. The magnetisation direction is parallel to the Earth’s magnetic field in that location. This is largely related to the presence of magnetic minerals such as magnetite. – Remanent Magnetisation – When a material is magnetised permanently in a direction aligned with bedding, laminations or other anisotropic structures. The magnetisation direction may oppose the Earths main field to produce unusual negative anomalies. – Density – Rocks have variable density or in other terms, mass per unit volume. For example, a basalt would typically display a density of 3 grams per cubic centimetre while a quartzite would typically display a density of 2.67 grams per cubic centimetre. – Conductivity – The capacity of a material to conduct an electric current. In Electromagnetic surveys, this current is induced through an artificially generated electromagnetic field. Certain sulphide minerals, graphite, shale and salty groundwater horizons display a high conductivity, while unweathered, non-porous bedrock displays low conductivity. • The key point is that geophysical modelling relies on a contrast in physical properties between the target of interest and the surround rock such as: – A density contrast: A low density salt dome in a more dense sedimentary host rock – A magnetic susceptibility contrast: A magnetically susceptible dolerite dyke in a magnetically quiet granite host rock – A conductivity contrast: A conductive sulphide vein in a resistive bedrock host Total Earth Solutions: Capabilities
  • 12. 12 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. • The basin margins • Basin symmetry/asymmetry • Depocentres/Thickness of Sedimentary Packages/Depth to basement • Base of major stratigraphic units • Intrabasin volcanics • Basin Involved Structures What is Basin Architecture? – 2D Seismic Example • Intra-basin faults • Basin History (Inversion?) • Major Salt structures • Seismic data is the benchmark for basin architecture studies, particularly in resolving structures at depth • Seismic is very expensive – what are the alternatives? *From: Carr et al STRUCTURAL AND STRATIGRAPHIC ARCHITECTURE OF WESTERN AUSTRALIA’S FRONTIER ONSHORE SEDIMENTARY BASINS: THE WESTERN OFFICER AND SOUTHERN CARNARVON BASINS
  • 13. 13 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. TES Basin Architecture – Potential Fields Approach Overview *From: Carr et al STRUCTURAL AND STRATIGRAPHIC ARCHITECTURE OF WESTERN AUSTRALIA’S FRONTIER ONSHORE SEDIMENTARY BASINS: THE WESTERN OFFICER AND SOUTHERN CARNARVON BASINS 1. Definition of broad basin geometry in regions with limited and/or poor quality seismic data. 2. Basement and intra-basin structural interpretation. 3. Depth to basement modelling utilizing magnetic and gravity methods. 4. Defining basin architectural models through the integrated analyses of basement geometry and structure with the intra-basin structural configuration of sedimentary basins. • Interpretation team includes tectonic, regional and prospect geologists that understand geophysics intimately and the integration of those data with packages such as Kingdom, we understand the language of Oil and Gas explorers
  • 14. 14 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. First level text heading • Second level text with bullets – Third level text with bullets • Fourth level text with bullets – Fifth level text with bullets Traditional role of Aeromagnetics in Seismic Exploration – Only use it when you can’t do seismic?; Coarse Scale Reconnaisaance and Structure?
  • 15. 15 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. What else can you get from magnetic data? Magnetic Signal variation from a range of Depths
  • 16. 16 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Qualitative Interpretation of Magnetic Data: Basin Architecture: Basin Margins, Sub basins • Perth Basin (Onshore Part) – magnetic response; Eastern edge of basin well defined; • Sub basin area margins including lows (troughs) and highs (terraces) are only weakly correlated with magnetic response • Some deep magnetic basement responses • Defining Intra-basin Structures and depth to basement with magnetic data depends on the magnetic mineral content – not always possible
  • 17. 17 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Qualitative Interpretation of Magnetic Data: Basin Architecture: Salt Rupture Zones in the Officer Basin • Browne Salt Wall has breached the flat lying magnetic Table Hill Volcanics • “Breached” zone obvious in 1VD magnetic data • Strike slip offsets – i.e. intra-basin Structures, are visible in the salt wall magnetic response • This could provide the means to target further seismic surveys (salt wall = possible hydrocarbon trap) • Deep basement magnetic sources are also visible
  • 18. 18 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Qualitative Interpretation of Magnetic Data: Basin Architecture: Salt Rupture Zones in the Officer Basin • Browne Salt Wall has breached the flat lying magnetic Table Hill Volcanics • “Breached” zone obvious in 1VD magnetic data • Strike slip offsets – i.e. intra-basin Structures, are visible in the salt wall magnetic response • This could provide the means to target further seismic surveys (salt wall = possible hydrocarbon trap) • Deep basement magnetic sources are also visible
  • 19. 19 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Comparison of Seismic Data with Aeromagnetic data: Salt Rupture Zones in the Officer Basin Subtle first vertical derivative (1VD) Magnetic signature from breached Table Hill Volcanics Salt diapirs are generally well imaged in Seismic reflection Data In this case the Browne Salt Wall can be seen in the magnetic data because it has breached a sub horizontal magnetic layer (Table Hill Volcanics) Browne Salt Wall Table Hill Volcanics Salt wall?
  • 20. 20 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin Salt Walls – Gravity and Gradient Gravity Response of Forward Model (1) Gzz Gz [Gz]
  • 21. 21 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin Salt Walls – Gravity and Gradient Gravity Response of Forward Model (2) Gzz Gz [Gz]
  • 22. 22 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin Salt Walls – Gravity and Gradient Gravity Response of Forward Model (3) Gzz Gz [Gz]
  • 23. 23 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin Salt Walls – Gravity and Gradient Gravity Response of Forward Model (4) Gzz Gz [Gz]
  • 24. 24 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin Salt Walls – Gravity and Gradient Gravity Response of Forward Model (5) 2.8 g/cc 2.6 g/cc 2.5 g/cc 2.35 g/cc Gzz Gz [Gz]
  • 25. 25 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Basin Architecture from Aeromagnetic Data – Sedminentary Layer Sequence Mapping in the Canning/Amadeus Basins • Magnetic signal from shallow to deep sources • Surficial Dendritic drainage patterns • Subtle magnetic signatures from relatively shallow siltstones, sandstones, carbonates and conglomerates layers containing minor magnetite • Deep, long wavelength signals from basement sources
  • 26. 26 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Basin Architecture from Aeromagnetic Data – Sedminentary Layer Sequence Mapping in the Canning/Amadeus Basins • Magnetic signal from shallow to deep sources • Surficial Dendritic drainage patterns • Subtle magnetic signatures from relatively shallow siltstones, sandstones, carbonates and conglomerates layers containing minor magnetite • Deep, long wavelength signals from basement sources
  • 27. 27 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Magnetic Methods – Forward Modelling • A magnetic basement below non-magnetic basin fill • Strong magnetic response at basin edges • Less “intuitive” to model than gravity data in the case of deep basins (anomaly shape more complex) • Magnetic response of shallow or flat-lying “intra-basin” magnetic units (i.e. volcanics) is very ambiguous to model • Steep dipping dykes or contacts can be modelled more accurately than shallow or flat-lying bodies • Magnetic susceptibility (model property) can be variable across orders of magnitude even in the one geological unit Subtle magnetic response of shallow dipping unit Intra-basin Volcanics Strong response of basin edge
  • 28. 28 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Qualitative Basin Architecture: Gravity Data – Basin Margins, Sub basins Perth Basin – magnetic response; Eastern edge of basin well defined; Basin lows (troughs) and highs (terraces) weakly correlated with magnetic response Perth Basin – Gravity response; Eastern edge of basin well defined; Basin lows (troughs) and highs (terraces) generally well correlated with gravity response
  • 29. 29 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Gravity Methods – Forward Modelling 2 3.0 g/cc 2.65 g/cc 2.6 g/cc 2.5 g/cc 2.2 g/cc Density Contrast Basin/Basement 0.35 g/cc Faults interpreted from other data Thinning basin sediments modelled to fit increasing gravity response Drill hole with downhole density measurements and lithology
  • 30. 30 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Euler Methods 1 • Euler Deconvolution is a semi automated depth to source method that can be used with gravity or magnetic data • The process uses “windows” of a user specified size (number of cells or data points) that move the across the data in 2D or 3D. Large windows are suited to deep targets, small windows to shallow targets. • At each window location a depth solution is calculated with depth “Z” below surface and window offset X (2D) or X,Y (3D) with respect to the window centre • Statistics calculated for each depth solution, such as depth uncertainty and horizontal uncertainty, are used to filer the solutions at a later stage • The depth solutions can be calculated for different structural indices (SI) that relate to the type of structure/geological features that are expected in the area and the method used (magnetics or gravity). A high structural index (SI) indicates that the gravity/magnetic response drops off more rapidly with depth SI Magnetic Field Gravity Field 0Contact Sill/Dyke/Step 0.5Thick Step Ribbon 1Sill/Dyke Pipe 2Pipe Sphere 3Sphere n/a
  • 31. 31 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Euler Methods 2 First Vertical Derivative First Horizontal Derivative Vertical Gravity Component Euler Solution Window (7 data points) moves along profile (2D) and solves for x,z (2D) location of source body with user specified SI Spherical Source Body SI (Gravity) = 2 SI (Magnetics) = 3 Horizontal Offset (with respect to window centre) Depth Window Centre Note that this window size is well suited for the target SI, size, and depth
  • 32. 32 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Euler Methods 3 • Euler Deconvolution produces a vast amount of solutions most of which are spurious • A window that is too small relative to the source size/depth will not capture the full wavelength of the anomaly and the depth solution will be inaccurate • With large window sizes, interference from neighbouring source bodies, or multiple source bodies in a single “window” will produce poor depth estimates • Generally it is easiest to calculate solutions for all SI, followed by filtering • Basic statistical filtering (depth uncertainty, horizontal uncertainty etc.) is generally not adequate • Some Geological input is required to determine which SI solution set is best suited for each geological body (dykes, sills, intrusions etc.)
  • 33. 33 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Gravity Euler Methods 1 • Accurate calculated derivatives of potential fields require the original field to be sampled at a line or station spacing less than or equal to the depth of the source bodies of interest • Vertical and horizontal derivatives from wide, variably spaced gravity data are noisy and contain point aliasing around stations • As Euler depth solutions require horizontal and vertical derivatives as inputs to the calculations, they are not well suited to widely spaced gravity data • The noise introduced into the derivatives can lead to spurious solutions • Careful low pass or upward continuation can be used to minimise these affects, so that the data may still be used to calculate Euler Solutions for very long wavelength (deep) features at the expense of shallow features
  • 34. 34 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Gravity Euler Methods 2 Noisy First vertical derivative of widely spaced gravity data “Pimple” derivative artefacts from single gravity stations
  • 35. 35 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Magnetic Euler Methods 1 Deep Basin Moderately Deep Mafic/Ultramafic Strongly Magnetic Edge Of Basin Shallow Granite Body Shallow Dykes Example – Capricorn Basin – A variety of source bodies that will require different SI and window sizes
  • 36. 36 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Magnetic Euler Methods 2 Deep Basin Structural Index (SI) = 0; Tightly clustered, generally consistent depth solutions over the deep basin area; poor definition of dykes in South West
  • 37. 37 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Magnetic Euler Methods 3 Shallow Dykes Strongly Magnetic Edge Of Basin Structural Index (SI) = 1; Tightly clustered, consistent solutions over the shallow dykes and basin edges; scattered and inconsistent in deep basin area
  • 38. 38 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Magnetic Euler Methods 4 • One approach is to digitize and classify the main magnetic features into SI units SI=1 SI=0 SI=1 SI=1 SI=1 SI=1 SI=1 SI=0
  • 39. 39 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Magnetic Euler Methods 5 • The resultant depth to basement surface shows a deep basin in the east, with some near surface magnetic bodies superimposed • Further processing could include the removal of the shallow magnetic features to produce a more smooth and coherent DTB surface
  • 40. 40 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 41. 41 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. DTB – Gravity Methods 2 Perth Basin – magnetic response; Eastern edge of basin well defined; Basin lows (troughs) and highs (terraces) weakly correlated with magnetic response Perth Basin – Gravity response; Eastern edge of basin well defined; Basin lows (troughs) and highs (terraces) generally well correlated with gravity response
  • 42. 42 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry • Gravity • 1 milliGal = 1 mGal = 10-3 Gal • The average gravitational accelerationg ~ 9.8 m/s2 = 980 Gal ≈ 106 mGal • Gravity Gradiometry • 1 E = 10-9 s-2 = 0.1 mGal/km = 10-4 mGal/m • The average vertical gravity gradient Tzz ~ 0.3086 mGal/m = 3086 E
  • 43. 43 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry
  • 44. 44 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry “System Noise” • Signal to noise ratios of Airborne gravity (Gravity gz) and airborne gravity gradiometry (Gzz) across bandwidth 0.001 to approx 2Hz • Using a fixed acquisition speed of 60ms-1 this can be related to the wavelength of anomalies, i.e. the depth to the sources of interest • According to this graph, at this acquisition speed the Gravity gz is superior at wavelengths greater than 30km • The Gzz is superior at wavelengths shorter than 30km • This “crossover” point is still hotly debated • Measures can be taken to improve Gravity gz *From Arkex US patent 20140081595 A1
  • 45. 45 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry source depth versus signal energy distribution • Consider a monopole point source 100m below surface (i.e. a source where the depth of burial is much greater than the width of the source) • In terms of the Gz (gravity) response most of the energy is concentrated at wavelengths 4x depth of burial (i.e. 1000m depth = 4000m wavelength) • What depths of burial are important for O&G exploration? • What wavelengths are important for O&G exploration? • What system is adequate and what system is in excess of the required resolution? *After Dransfield Et Al,
  • 46. 46 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry: Improving Airborne Gravity through Noise Reduction • The noise in airborne gravity systems is reduced via filtering • The filters are specified by the length of time over which the filter operates • Longer filters reduce noise and resolution at a given acquisition speed • Minimum ½ sine wave resolution = ½ (acquisition speed (ms-1) x filter length) • Noise can also be reduced by averaging lines (where line spacing is less than the along line filter length) • Clients can tailor the line spacing/acquisition speed/filter length to suit their requirements *After Olsen 2010 * From Sanders AirGrav
  • 47. 47 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry near surface sources • Gravity gradiometry systems are very sensitive to near surface sources • Gravity systems are more sensitive to deeper sources • The response of shallow sources in gravity gradient data can obscure deeper sources *After Olsen 2010
  • 48. 48 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry – Basin Model Gzz Gz Salt dome apparent in both Gzz and Gz Near surface palaeo- channel and minor ridge causes strong response in Gzz Basement Offset (masked by adjacent basement density variation) Intrabasin offset (masked by nearby salt dome) Mafic Basement and dyke/sills (larger relative amplitude in Gz)
  • 49. 49 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry – Basin Model – With noise added 5 Eotvos RMS noise (400m cutoff) 0.2 mGal RMS noise (grey) 1 mGal RMS noise (grey dashed
  • 50. 50 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Airborne Gravity Vs Gravity Gradiometry – Basin Model Gzz Gz Salt dome apparent in both Gzz and Gz Near surface palaeo- channel and minor ridge causes strong response in Gzz Basement Offset (masked by adjacent basement density variation) Intrabasin offset (masked by nearby salt dome) Mafic Basement and dyke/sills (larger relative amplitude in Gz)
  • 51. 51 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Forward Modelling the Gz and Gzz response of a basement shelf interpreted from Seismic Data • An interpreted 2D seismic section was used to construct a basement model • The Gz and Gzz reponse of the model was calculated to determine the most appropriaate system
  • 52. 52 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Forward Modelling the Gz and Gzz response of a basement shelf interpreted from Seismic Data • The depth of the shelf is approximately 2000m
  • 53. 53 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Forward Modelling the Gz and Gzz response of a basement shelf interpreted from Seismic Data • Gz response with estimated system noise added • Gzz response with system noise added • Both resolve the feature of interest • Which one is more cost effective?
  • 54. 54 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Forward Modelling the Gz and Gzz response of a basement shelf interpreted from Seismic Data • Gz response with estimated system noise added • Gzz response with system noise added • Both resolve the feature of interest • Which one is more cost effective?
  • 55. 55 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Example – Interpretation using available magnetic and radiometric data, imagery and Legacy geological mapping
  • 56. 56 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 57. 57 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 58. 58 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 59. 59 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 60. 60 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 61. 61 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
  • 62. 62 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne RTP
  • 63. 63 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne RTP 1VD
  • 64. 64 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne RTP plus seismic interp
  • 65. 65 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne RTP plus werner solutions
  • 66. 66 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne THV plus mag interp
  • 67. 67 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne Seismic Interp Map
  • 68. 68 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Officer Basin: Browne Basement Lithology Map
  • 69. 69 Copyright © 2015 Total Earth Solutions All rights reserved. Confidential. Pre – Salt: How can potential fields add value • Pre salt hydrocarbon exploration takes place at great depth – Great depth: • long source wavelengths Suitable for Airborne gravimetry • Poorly imaged seismic data at depth or obscured by salt structures – Shallow gravity gradiometry and magnetic data may assist with static corrections to seismic data – Airborne Magnetic data may provide DTB estimates (base of Pre-salt formation) – Constraint of potential field geophysical modelling through well data and seismic sections – Identification of Radial or sub paralell faults associated with active diapirs – Identification of extensional structures that focus salt emplacement – Interpolate structure between 2D seismic lines – Estimates of salt thickness where seismic is poorly imaged, ie, based on the calculated thickness below the top of the salt as imaged in the seismic data via gravity modelling, and constrained with wells where possible – Estimates of density to use in gravity models based on downhole tools

Hinweis der Redaktion

  1. In the last 5 years the role airborne magnetics plays in oil and gas exploration has changed dramatically … for the better we hope. Traditionally airborne magnetics surveys were only flown in regions where seismic acquisition was difficult or where the quality of the seismic data was poor or non existent. As well as being used as a regional reconnaissance tool for mapping out the extent and depth of basins the technique was employed for differentiating between salt and granite as well as mapping out basement structuration. With High Resolution Magnetics we are able to better address these issues but also investigate the sedimentary section which was previously thought to be non magnetic. We now know differently.
  2. Correcting that misunderstanding is the key to this presentation. The sediments are weakly magnetic. We can detect their susceptibility and from that we can determine the structure within the sedimentary section. As an example I want you to look at these sketches where we show the magnetic response as the geology gets increasingly complicated. Here we see the intrasedimentary magnetic response due to a fault superimposed on the gross magnetic response due to uplifted basement. As the lithology of the basement becomes more complicated the magnetic anomaly changes. High Amplitude, slowly changing components of the anomaly are generated by basement changes whereas low amplitude, higher frequency components are generated by changes with in the sedimentary sections. The lower two plots show the difference between faulting in the basement only compared to those that extend through the sedimentary section. Detecting these intrasedimentary changes is possible for a number of reasons: our survey instruments are now more sensitive and the way in which we acquire and process the data has become more sophisticated.