sedimentary geology geos 240 – chapter 2 collecting the data part 1 geological, stratigraphic...
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Sedimentary GeologySedimentary GeologyGeos 240 – Chapter 2Geos 240 – Chapter 2Collecting the DataCollecting the Data
Part 1 Geological, Part 1 Geological, Stratigraphic & Petrophysical Stratigraphic & Petrophysical
DataDataDr. Tark HamiltonDr. Tark Hamilton
Camosun CollegeCamosun College
Collecting the DataCollecting the Data
Stratigraphic Sections from Surface Stratigraphic Sections from Surface OutcropsOutcrops
Petrophysical logging of boreholesPetrophysical logging of boreholes Well cuttings and coresWell cuttings and cores Regional GeophysicsRegional Geophysics Labwork on sediments, rocks, fossils, Labwork on sediments, rocks, fossils,
fluidsfluids Computer/Office: Mapping, Computer/Office: Mapping,
Interpretation & ModellingInterpretation & Modelling
Measuring a Measuring a Stratigraphic SectionStratigraphic Section
Gayna River near Norman Wells NWTGayna River near Norman Wells NWT
Western Canada Sedimentary BasinWestern Canada Sedimentary Basin
Measuring with a Jacob’s Measuring with a Jacob’s StaffStaff
Use a 1.5 m stick with a level or dip arrowUse a 1.5 m stick with a level or dip arrow Site along to next 1.5 m position in true thickness position and Site along to next 1.5 m position in true thickness position and
add!add! One potato two potato three potato four!, Five potato Six potato…One potato two potato three potato four!, Five potato Six potato…
Strip Log – Stratigraphic Strip Log – Stratigraphic SectionSection
Grain Size increases to right = resistance to weatheringGrain Size increases to right = resistance to weathering Sands>> stick out while Shales<< are recessiveSands>> stick out while Shales<< are recessive
Castlegate Sandstone: UtahCastlegate Sandstone: Utah
Horizontal Photos & Line Drawing showing Horizontal Photos & Line Drawing showing bedding, sequence boundaries & paleocurrent bedding, sequence boundaries & paleocurrent directionsdirections
~1 week’s work~1 week’s work
ComponeComponents of a nts of a Modern Modern
ExploratioExploration Rig on n Rig on
LandLand
Drilling Drilling Details:Details:
Mud Mud Lubricates, Lubricates,
Cools, Cools, Prevents Prevents Blowouts, Blowouts,
Carries Carries Cuttings & Cuttings &
FluidsFluids
Roller Bits For Various Hole Roller Bits For Various Hole SizesSizes
For Hard Rocks (Sandstones & Limestones)For Hard Rocks (Sandstones & Limestones) Blade Bits are used for clays, coals and soft shalesBlade Bits are used for clays, coals and soft shales
Core, Core Boxes & CuttingsCore, Core Boxes & Cuttings
Description is the major work of most wellsite geologistsDescription is the major work of most wellsite geologists Core “libraries” at ISPG Calgary & Charlie Lake, NEBCCore “libraries” at ISPG Calgary & Charlie Lake, NEBC
Coring Tools: Full Core & Coring Tools: Full Core & SidewallSidewall
Energy Resources Energy Resources Conservation Board: ISPG & Conservation Board: ISPG &
University of CalgaryUniversity of Calgary
Detailed Well LogDetailed Well Log
Formation Symbols at Left, SP & Gamma LogsFormation Symbols at Left, SP & Gamma Logs Lithologic interpretation, Detailed descriptionsLithologic interpretation, Detailed descriptions
Table of Petrophysical Table of Petrophysical LogsLogs
Fluids vs Rock
Brine, Gas, Oil
Logs vary w/Diam
Low Dens Coal Salts
FMS TV Pictures Sedimentary structuresXRF Induced Gamma Ray Fluorescence Chemistry/Mineralogy
Physical Properties of Physical Properties of Formation near a BoreholeFormation near a Borehole
Drilling Fluids: mud, salts, ions, water Drilling Fluids: mud, salts, ions, water movemove
Natural Gamma Measures Natural Gamma Measures Shaliness due to Shaliness due to 4040K in clay K in clay
mineralsminerals
Nunavut
Common Petrophysical Common Petrophysical Logs: SPLogs: SP
Shales have + SP response, high CEC, NaShales have + SP response, high CEC, Na++ moves into mud moves into mud Permeable Sands have –SP response. ClPermeable Sands have –SP response. Cl -- is more mobile as is more mobile as
mineral surfaces are negatively charged (silicates)mineral surfaces are negatively charged (silicates)
Petrophysical Logging: SP & Petrophysical Logging: SP & ResistivityResistivity
SP –Sand line to left, +Shale Line to rightSP –Sand line to left, +Shale Line to right Resistivity tool has different depths of penetrationResistivity tool has different depths of penetration
Petrophysical Logs: Caliper & Petrophysical Logs: Caliper & ResistivityResistivity
Shales are soft so hole cuts to a Shales are soft so hole cuts to a bigger diameterbigger diameter
Mudcake
Mudcake
Fresh Water Invasion
Petrophysical Logs: Neutron & Petrophysical Logs: Neutron & DensityDensity
Petrophysical logs: Petrophysical logs: Dipmeter & FMSDipmeter & FMS
Channel Sands in ShalesChannel Sands in Shales
SandsL.Cretaceous
Jurassic
THIS COVERS MOST THIS COVERS MOST CONVENTIONAL CONVENTIONAL
SEDIMENTARY GEOLOGY FOR SEDIMENTARY GEOLOGY FOR RESOURCE EXPLORATIONRESOURCE EXPLORATION
End of Chapter 2 Part 1 End of Chapter 2 Part 1 (Strata, Sedimentary Rocks & (Strata, Sedimentary Rocks &
Well Logs)Well Logs) Mining Exploration, Environmental, Mining Exploration, Environmental,
Geotechnical, Aquifer, Academic & Geotechnical, Aquifer, Academic & Archeological studies all do similar things Archeological studies all do similar things but with smaller tools, areas of interest and but with smaller tools, areas of interest and way smaller budgets!way smaller budgets!