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Introduction to
Total Earth Solutions (TES)
TES - Services avaibale to the Oil and Gas Industry
2Copyright © 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.
3Copyright © 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.
4Copyright © 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.
5Copyright © 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:
6Copyright © 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:
7Copyright © 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:
8Copyright © 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:
9Copyright © 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:
10Copyright © 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:
11Copyright © 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
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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
13Copyright © 2015 Total Earth Solutions All rights reserved. Confidential.
TES Basin Architecture – Potential Fields ApproachOverview
*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 DataIn 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 VolcanicsSalt 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
27Copyright © 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
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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/cc2.2 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 Field0 Contact Sill/Dyke/Step
0.5 Thick Step Ribbon1 Sill/Dyke Pipe2 Pipe Sphere3 Sphere 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 BodySI (Gravity) = 2SI (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 EdgeOf 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 EdgeOf 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=1SI=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 2Perth 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 gradientTzz ~ 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