PNGE 450 EXAM 1 Introduction Flashcards

1
Q

Formation Evaluation

A

Covers a very wide range of measurement and analytic techniques

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2
Q

Geophysics:

A

seismic studies

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3
Q

Geology:

A

stratigraphy, sedimentology, lithology

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4
Q

Petrophysics

A

core analysis, log analysis

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5
Q

Drilling Eng.:

A

mud properties, rock properties

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6
Q

Reservoir Eng.

A

reservoir limits, storage capacity, economic value, EOR considerations

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7
Q

Production Eng.

A

fluid type, fluid pressure, completion considerations, productivity, injectivity

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8
Q

Formation Evaluation Methods

A
  • Mud Logging
  • Coring/Core Analysis
  • MWD/LWD
  • Formation Testing
  • Openhole Logging
  • Cased-hole Logging
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9
Q

Well Logging
Measurement of formation properties vs. depth:

A
  • Rock properties
  • Fluid properties
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10
Q

Two types of Well Logging

A

1) Openhole (before casing)
* Conventional (wireline) logging
* LWD/MWD
2) Cased hole

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11
Q

Interpretation:

A
  • Geology
  • Petrophysics/reservoir
  • Completion/production
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12
Q

Openhole logs can provide either a direct measurement or a good indication of:

A
  • Porosity, both primary and secondary (fractures and vugs)
  • Permeability
  • Water saturation and hydrocarbon movability
  • Hydrocarbon type (oil, gas)
  • Lithology
  • Formation dip and structure
  • Sedimentary environment
  • Travel times of elastic waves in a formation
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13
Q

Cased hole logs can provide

A
  • Flow rates
  • Fluid type
  • Pressure
  • Residual oil saturation
  • Cement bond log
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14
Q

Pros

A
  • Provides most abundant data from the formation
  • Very reliable
  • Provides vertical and lateral (map) variations in rock/fluid properties
  • Modest cost
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15
Q

Cons

A

Indirect measurement
* Depth of investigation
* Vertical resolution
* Nuclear hazards

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16
Q

1912:

A

Conrad Schlumberger, recorded the
first map of equipotential curves at his estate
near Caen in Normandy, before extending
his surveys to iron mines in the area

17
Q

9/5/1927:, 1929:

A

9/5/1927: Measurements were taken from an
electrical sonde at various discrete depths in a 500
meter-deep well in Pechelbronn in the Alsace region
of France.
From Schlumberger
1929: The USA’s first ever well log is performed in Kern
County, California

18
Q

2 Types of logging cables

A
  1. Monoconductor:
  2. Multiconductor:
    * Completion services: perforation, setting packers
    * Production logs: flow, Temp.
    * Openhole surveys
19
Q

Openhole Logging Procedure

A
  • Logging truck is anchored about 100 to 200 ft from the well.
  • Lower sheave is chained down near the rotary table.
  • Upper sheave is suspended from the crown block.
  • Logging tool (sonde) is placed on the cat walk.
  • The logging cable from the truck winch is passed over the sheaves,
    attached to the logging tool string.
  • Lift the tool to the rig floor.
  • Set the depth reference.
  • Run the tool to the total depth (TD).
  • 300 ft repeat section.
  • Run the tool back to TD.
  • Complete survey
20
Q

Openhole Measurements
Passive (Natural Response):

A
  • Caliper
  • SP (Spontaneous Potential)
  • Gamma Ray: Natural GR, Spectral G
21
Q

Openhole Measurements
Active (Induced Response):

A
  • Sonic (Acoustic)
  • Nuclear: Neutron, Density, photoelectric
  • Electric/Electromagnetic: Resistivity, Induction, NMR
22
Q

Log Presentation

A
  • Header
  • Tool info and Remarks
  • Tool sketch and description
  • Log Curves
  • Repeat Section
  • Before/After Survey check
23
Q

Radius (depth) of invasion depends on:

A
  • Formation properties: porosity, permeability
  • Pressure difference between mud and formation
  • Drilling fluid properties: water/oil based, viscosity
  • Time
24
Q

Mud Filtrate Invasion Terminology
Uninvaded Zone

A

Rt : Uninvaded formation resistivity (true resistivity)
Rw : Formation water resistivity
Sw : Uninvaded formation water saturation

25
Q

Flushed Zone

A

Rxo : Flushed zone resistivity
Rmf : Mud filtrate resistivity
Sxo : Flushed zone water saturation

26
Q

Wellbore

A

Rm : Mud resistivity
Rmc : Mud Cake Resistivity
hmc : Mud cake thickness

27
Q

Caliper Log Application

A

Wellbore size and shape evaluation
 Indicator of permeable zones from mud cake deposition
 Hole volume estimation for cementing
 Application for other logs wellbore correction
 Determine candidate zone for setting packers
 Evaluating the casing for corrosion or breakage in cased-holes

28
Q

Caliper Log

A

d wellbore < d drilling bit
d wellbore = d drilling bit
d wellbore > d drilling bit
Mud cake deposition
On gauge
Wash out
Permeable zone indicator
Brittle shales
Dissolution : salts
Poor cementation

29
Q

Caliper Log 2

A
  • Usually on Track 1
  • Linear
  • Increasing left to right
    look at log from introduction log slide 33