Exploring 3-D Data Sets With GIS

Damion Knudsen

Background

•BS in Geology•Minor in Chemistry•Pursuing MS•Advisor Dr. Bernhardt Saini-Eidukat, Chairman of the Geosciences Department at NDSU

North Dakota State University Environmental and Conservation Sciences Program and Dakota Technologies, Inc. in Fargo, North Dakota

People I would like to thank for data sets and guidance in the preparation of this presentation are:

Dr. Bernhardt Saini-Eidukat, Dr. Frank Casey, and Dr. Peter Oduor of NDSURandy St. Germain, President of Dakota Technologies, Inc. of Fargo, North DakotaDr. Rinita Dalan of Moorhead State UniverisityBruce Juenker of the NDIC Oil and Gas DivisionKris Roberts of the NDDH Ground Water Division

Classic 2-D GIS

2-D GIS gives the following ways to represent 3-D structures

•Filled and Line Contours•Shaded Relief Maps•Tins•Raster Grids•Cross Sections

Google Earth has revolutionized the visualization of the 3-D Earth and has become popular among casual computer users

ArcGlobe and ArcScene have much more capabilities than Google Earth.

Google recently bought SketchUp from @Last Software. It will be interesting to see how that works out.

I will give examples of other ways that GIS can be used to represent the 3-D environment

North Dakota Geology

In this first model I will show an example map of the subsurface geology of North Dakota produced from borehole data readily available from the NDIC Oil and Gas Division.

•This solid model was formed from approximately 14,000 wells across North Dakota

North Dakota Geology

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North Dakota Geology

•View Facing South East •Solid regions below the surface represent major oil producing formations

Examples:

Madison Group

Red River Formation

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North Dakota Geology

•Here is another view with cross sections and North Dakota counties floating over head

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North Dakota Geology

•Cross Section reveals

Nesson anticline

•Structure suggests mid Jurassic down warp 100x vert. exag.

•View Looking South •View Looking East

North Dakota Geology

•The Foreman Butte oil field in McKenzie County of North Dakota produces largely from the Madison Group

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North Dakota Geology

•Oil Well boreholes are represented by blue points

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•A major producing region of the Madison Group in the Foreman Butte oil field is considered the Ratcliffe Interval•These cross sections represents oil saturation in percent scaling from 0% to 97% versus water

Oil Producing Field in McKenzie County

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Oil sat. in %

Porosity and resistivity 3-D grids are used to calculate oil saturation

using the Archie equation

Oil Producing Field in McKenzie County

•Porosity cross sections

•Resistivity cross sections

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•Oil Saturation cross sections

1- Sw

•These are Iso-surfaces representing the intersection of 8 % porosity with 45% oil saturation•An iso-surface is considered to be a 3-D contour

Oil Producing Field in McKenzie County

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•Iso-surfaces can be compressed to 2-D and overlaid on a plan map to delineate the areas of potential oil production

Oil Producing Field in McKenzie County

Groundwater Non-Aqueous Phase Liquid (NAPL) Contaminant Characterization Using Laser Induced

Fluorescence (LIF) and 3-D GIS in Morton County, ND

•Boreholes representing LIF response through a free phase diesel fuel source term in Morton County

•Cross section of source term plume drawn through boreholes

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% RE

Groundwater Non-Aqueous Phase Liquid (NAPL) Contaminant Characterization Using Laser Induced

Fluorescence (LIF) and 3-D GIS in Morton County, ND

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•Iso-surfaces of free phase diesel within the water table•LIF acquires data at approximately 1 inch intervals.•Dakota Technologies, Inc. uses LIF to collect data as shown above

% RE

NDSU Oakes, ND Nitrate leaching study area

•This study area was used to research the leaching of nitrates through groundwater

•Solid model with aerial photo draped on surface

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NDSU Oakes, ND Nitrate leaching study area

•Sand and sandy loams

•Soil pH iso-surface

•Clays and clayey loams

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pH

NDSU Oakes, ND Nitrate leaching study area

•Sand and sandy loam Cross sections

•Soil pH iso-surface

•Clays and clayey loam in voxel (3-D pixel) format

•Groundwater NO3 -

concentration

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pH

NDSU Oakes, ND Nitrate leaching study area

•Solid hydraulic conductivity model of area.

Units in in/hr

•Model mesh could be used in ModFlow??

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•Area thought to contain remains of ancient activity including firepits

Archaeological Site in Cass County, North Dakota

•Use of Magnetic Susceptibility, LIDAR, and 6 inch resolution images in model

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•Fire pits should leave remains of reduced iron in the form of magnetite or similar minerals. •Paleosols and the A horizon should have the least amount of these minerals shown in pink

Archaeological Site in Cass County, North Dakota

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•Cross sections

•Paleosols•Possible fire pits in red.

Archaeological Site in Cass County, North Dakota

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•Iso-surfaces of possible fire pits in blue.

Archaeological Site in Cass County, North Dakota

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Areas of Improvement• ArcScene has not changed much in 5 years• Would like to see 3-D editor in ArcScene and ArcGlobe• Ability to publish maps similar to ArcGlobe and ArcMap.• 3-D measurements in ArcScene• Automatic 3-D legend and graticule options• 3-D selections between a volume or separate raster

grids or tins• 3-D interpolations and iso-surface generation in 3D

Analyst• Volumetric measurements of 3-D iso-surface models

Observations• Higher resolution subsurface data will always provide the most

accurate representation of a subsurface distribution.

Forms of high resolution data available today are:• Laser Induced Fluorescence (LIF) UVOST or TarGOST• Cone Penetrometer Test (CPT) This can be used in conjunction with

a LIF system• Magnetic Susceptibility• Wireline and Measuring/Logging While Drilling (M/L WD) tools used

in the petroleum industry and for geophysical testing • When collecting subsurface data it is always best to acquire highly

accurate coordinates and elevations for your data if you plan to use it for 3-D mapping.

Future Applications

• 3-D data could be supplied from an IMS server to be viewed through the internet similar to Google Earth

• Practical in a few years when Vista forces people to use 3-D acceleration and internet speeds increase

Thank You

Questions?