Post on 09-Mar-2016
description
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Nick Nelson
Geologist / SEM Engineer
Whiting Petroleum Corporation
October 8th 2013
Outline
My Experience
What is Mudlogging ? ? ?
Data Collection Procedure
How to Read a Mudlog
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Experience
B.S. in Geology from Fort Lewis College
Softrock Geological Services 2005-06
Datalog / International Logging 2006-07
Redwine Resources 2007-09
GeoSearch Logging 2009
Whiting Petroleum 2010-Present
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What is Mudlogging ? ? ?
Mudlogger or Wellsite Geologist
Eyes and ears of the office Geologist
Monitor gas levels while drilling
Identification of potential pay zones
Safety of rig personnel
Describe cuttings properties for
preliminary reservoir characterization
White Light
UV
What data is collected
Rock Data
Drilling Data
ROP
Gamma
Directional Information
Two gas Curves
Total Gas
Chromatograph Gas
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Open Pits
Circulation Pits
Flare
Shaker / Possum Belly
Shakers
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Shakers
Rock Samples
Gas Trap
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Gas Trap / Mud Gas
Gas Detector Gas Detector
Possum Belly
Pumps Flow Line
Pits
Shakers
Mudlogging
Trailer
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What is Gas ? ? ?
Total Gas is exactly what it says
All hydrocarbons are burned together on a
Hot Wire (filament)
Does not distinguish between gas species
Continuous Reading
Chromatograph Gas
Separates out C1 to C5 (standard)
Can separate C1-C10 (mass spec)
3-5 minutes per sample run
Gas 101
Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
Pentane C5H12
C
H
H
H
H
C
H
H
H
C
H
H
C
H
H
H
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Gas Trap Flow
Helium Carrier Gas
Partition or Column
C2 C1 C4 C3
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Lag Time
The time it takes for Gas and Rock
samples to make it from the drill bit to
the surface, and ultimately the shaker
and gas detection equipment
Increases with depth and amount of
open hole, not behind casing
Always an estimate except when:
Lag Bomb
Diagnostic formation appearance
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Known Information
- Time / Pump Strokes from Surface to bit
- Time / Pump Strokes from casing to surface
Unknown Information
- Time / Pump Strokes fluid spends in open
hole environment
- How much washout has occurred
Lithology Description
Rock Type Sandstone, Limestone, Shale, Evaporates
Color
Shape Rounded, Angular, Blocky
Grain Size and Sorting
Minerals Pyrite
Extra Important Information Cut, Fractures, Fossils, Metal
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Cut
Can and should be described under
White Light or by Ultra Violet Light
Gives a relative Porosity and
Permeability measurement
Types / Names of Cut
Streaming
Pooling / Rimming
Even
Spotted
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Cryptic Descriptions
Siltstone: Medium Grey, Sub Blocky, Grading to Sandstone Translucent to Off White
to Salt and Pepper, Fine to Very Fine Grained, Sub Rounded to Sub Angular, Poorly
Sorted, Poor Cement, Calcite, Abundant Coal, Abundant Carbonaceous, Really Rare
Crystalline Calcite
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Cryptic Descriptions
Sandstone: Off White-Tan-Salt and Pepper in color, Very Fine-Fine Grained,
Subangular-Subrounded, Well Sorted, Moderate Cement, Slight to Moderate amount
of Calcite, Some White Clay Filled pores, Trace Yellow Mineral Fluorescence,
Trace ????, No Stain or Cut