Operational Support Group - OSGJochem Kück

GeoForschungsZentrum Potsdam

Lake Lake BosumtwiBosumtwi, Ghana 2004, Ghana 2004

Downhole Logging

ICDP Training Course

Overview

Technical Principles

Basic Terms

Borehole Geometry Logging

Temperature Logging-----------------------

Image Logging

Geophysical Logging----------------------

Hydraulic & Fluid Logging

Overview cont.

Log Quality

Technical Services

CREOS - Core Orientation----------------------

Deviated Hole Logging----------------------

OSG Equipment----------------------

Technical Principles

DrillRig

What is Borehole Logging?

Logging Cabledownhole

Logging Sonde

ICDP

Logging Truck

GFZ, OSG, J.Kück

Principles of a Logging Set Up

ICDP upper sheavehanging from the hook

lower sheaveattached to derrick floor

logging cable

logging truck or skid unit

drill rig

GFZ, OSG, J.Kück

Well Logging TruckExample:Schlumberger International Typ 26

Truck engine also powers the winch

Winch control panel

Optional winch with coaxial cable

Data acquisition computer Winch with 7-conductor cable

Depth measuring system

GFZ, OSG, J.Kück

GFZ, OSG, J.Kück

Drilling Vessel

Lake Logging

LoggingWinch

Slimhole Logging Equipment

Example: GFZ/Antares

GFZ, OSG, J.Kück

Depthmeasuring

system

Electric motor

Winch control & sonde panel

Data acquisitioncomputer

Winch with 4-conductor cable

Well Logging Cable - Scheme

Example: Vector Cable 7-46 P Outer diameter: 0.464" = 11.79 mm

Weight in air 498 kg/km in water 393 kg/km

Temp. max: 150 °CBreak strength: 52 kN

(11600 lbf)Filler rods,filler compound & tape binder

Electric lines: Copper: 0.32 mmInsulation: 2.49 mmResistance: 36 Ohm/km

Armor, hi-tensile, galvanised steelInner armor: 24 wires, 0.99 mmOuter armor: 24 wires, 1.24 mm

GFZ, OSG, J.Kück

Well Logging Cable - Scheme

Example: Vector Cable, hybrid electro-optical logging cable

Optical fibre in the center

Filler rods,filler compound & tape binder

Electric lines (Copper)

contrahelically windinginner armor & outer armor

GFZ, OSG, J.Kück

Connection between

Cable and Sonde

Cable Head

- pressure-tight- fast connect / disconnect- tough

Example: Schlumberger7-conductor, 3 3/8"

airpressure

boreholepressure

weak point

airpressure

boreholepressure

pressure-proof electricalconnectors on feed throughs

pressure-proof electricalconnectors between cablewires and cable head wires

rope socket,holds sonde weight

GFZ, OSG, J.Kück

connection with sonde

Cable Head

! Upper housing removed !

Example: GFZ geophone sonde BG250

Electronics SensorsMotor

compensation piston under oil

Characteristics of a borehole logging sonde

arm

3 times 2 o-rings o-ring and

wiper ring2 o-rings

2 o-rings

7 seal electrical connectors

GFZ, OSG, J.Kück

Typical Sonde Electronics Chassis & Pressure Housing

Example: Telemetry Sonde, Schlumberger

GFZ

-OSG

, J. K

ück

Borehole = Harsh Environmenthi-T & hi-P

Example of a destroyed (collapsed) sonde housing

wall thickness: 16 mm Ø = 110 mmmaterial: stainless steeldepth of dammage: 6000 - 7700 mpressure: 69 - 85 MPaequiv. acting weight: 700 - 850 kg/cm2

GFZ, OSG, J.Kück

Basic Termsof Logging

Basic Terms in Downhole LoggingDepth

Observation ScaleBorehole Effects

Mud Invasion / Mud CakeDepth of Investigation

Vertical ResolutionMeasuring Range & Accuracy

Log Quality

GFZ, OSG, J.Kück

Depth Measuring SystemExample: Schlumberger

GFZ

-OSG

, J. K

ück

Example: Schlumberger In-Line Tensiometer, 3-point bending

Cable Tension - Tensiometer

GFZ, OSG, J.Kück

GFZ, OSG, J.Kück

Combination: Depth & Tension

Example: Schlumberger

Depth Measuring System

GFZ-OSG, J. Kück

Example: GFZ / Antares

Tensionmeasurement

Depthmeasurement

Depth Measuring System

GFZ-OSG, J. Kück

Example: GFZ / Antares

Depth Mesurements in a Borehole

Each wireline log has its own depth!

Logging Depth

Core Depth

Cuttings Depth

Mud Sample Depth

Driller Depth

GFZ, OSG, J.Kück

There is no absolute depth measurement in a borehole!

3716

3717

3718

3719

3720

3721

3722

0 50 100 150

0 50 100 150

3700

3710

3720

3730

3740

0 50 100 150

0 50 100 150

3700

3710

3720

3730

3740

0 50 100 150

0 50 100 150

Logging data is aquasi-continous data set

GFZ, OSG, J.Kück

3716

3717

3718

3719

3720

3721

3722

0 50 100 150

0 50 100 150

Sampling space: 20 cm

dep

th/m

GR

0 50 100 150GR / API

GFZ-OSG, J. Kück

3550

3555

dep

th/m

3590

3570

3575

3580

3585Example:KTB-VBpilot hole

- GR-1

- GR-2

Log-to-Log Depth Correlation - GR Matching

0 50 100 150GR / APILog-to-Log Depth Correlation - GR Matching

GFZ-OSG, J. Kück

3550

3555

dep

th/m

3590

3570

3575

3580

3585Example:KTB-VBpilot hole

- GR-1

- GR-2 shifted

Depth MeasurementComparison of Driller Depth and Logger Depth

Example: KTB main hole, section 0 - 6000 m

0 1000 2000 3000 4000 5000 6000

Driller Depth [m]

Difference Driller-Logger [m]

0

2

4

6

8

10

12

Measured difference from CCL

Calculated elongation of drill string

GFZ, OSG, J.Kück

Casing Collar Locator, CCL

Calculated

Thin sections &cuttings

Core plugs & side wall mini cores

Cores

Well logs

Far sensing well surveys

Surface geophysics

Borehole Seismics,Gravimetry, Magnetics,

Electromagnetics, Hydraulic Tests, etc.

10-2 10-1 10 1021

Scale, in meters

1 cm 10 cm 1 m 10 m 100 m

Scale of integrated observation volumes

GFZ, OSG, J.Kück

Tra

nsi

tio

n z

on

e

Logging Integration Volumeusually `looks` non-directional

Core & Sidewall Coresdeliver data strongly

dependent on the measuring direction

Directional Logging Sondes

A n i s o

tr

py

GFZ, OSG, J.Kück

Tra

nsi

tio

n z

on

e

Mud Shoulder bed

Shoulder bed

Flu

shed

zo

ne

Tra

nsi

tio

n z

on

e

Un

dam

aged

zo

ne

Mu

dca

ke

Bedthickness

h

Rxo

Rmc

Rt

RmfRw

RmRs

Resistivity of the zone

Resistivity of the water in the zone

Sediments

GFZ, OSG, J.Kück

Tra

nsi

tio

n z

on

e

Mud Shoulder bed

Zone with drillinginduced fractures

Un

inva

ded

zo

ne

Bedthickness

h

Rt

Rw

RmRs

Rxo

Rmf

Zone with mud invaded fracture systems

GFZ-OSG, J. Kück

Crystalline

Resistivity of the zone

Resistivity of the water in the zone

Tra

nsi

tio

n z

on

e

VerticalResolution

90%70%

Depth ofInvestigation

90%

Sonde readings

GFZ, OSG, J.Kück

Depth of Investigation of Logging Sondes

Resistivity

Sonic

NuclearSondes

Imager

GFZ, OSG, J.Kück

Logging Sondes=

Instruments to find Oil & Gas

Priority=

Determine the Water Saturation!

(Porosity, Lithology, Permeability)GFZ, OSG, J.Kück

0 10 20 30 40 50 60 700

5

10

15

20

25

30

35

Effect of Pororsity on the Depth of Investigation

Po

rosi

ty /

%

Depth of Investigation / cmGFZ, OSG, J.Kück

What can be measured?

FluidFluid Parameters:

RockRock Parameters:

Natural Gamma Activity Sonic Velocities DensityElectric & Magnetic Properties

Elemental CompositionStructures on the Borehole Wall

Gravity Field 3D Orientation

Rock Samples

Temperature PressureResistivity DensityFluid Samples Fluid Flow

GFZ, OSG, J.Kück

Wireline Logging Methods -1-

Type Method Code

Induction LogPhasor InductionLaterologsMicro Resistivity LogSelf and Redox PotentialInduced PolarisationElectromagnetic Propagation

Stratigraphic DipmeterMicro Electrical ImagerArray Resistivity ImagerBorehole Televiewer

Natural Gamma RaySpectral Gamma RayLitho DensityGeochemical LoggingNeutron PorosityNuclear Magnetic Resonance

DILPIDLLMSFLSPIPEPT

SHDTFMSARIBHTV

GRSGRLDTGLTCNTNMR

Resistivity

Structures

Density &Porosity

GFZ, OSG, J.Kück

Wireline Logging Methods -2-

Type Method Code

Borehole Compensated SonicSonic Long SpacingSonic Digital (Array) ToolDipole Shear Sonic ImagerArray Seismic ImagerBorehole Geophone

Borehole Geophone/SeismometerBorehole Gravity Meter

3-D MagnetometerMagnetic Susceptibility

Borehole TiltmeterThermal Conductivity

BCSSLSSDTDSIASIBG

BG/BSBHGM

MAGMSUS

BTMWLF

Acoustic

LargeScale

Magnetics

Diverse

GFZ, OSG, J.Kück

Wireline Logging Methods -3-

Type Method Code

Sidewall Coring ToolFormation Tester, open holeCased Hole Formation Tester

Fluid SamplerFlowmeterFluid DensityMud-Temperature/-Pressure/-ResistivityDistributed Optical Fibre

Temperature SensingPacker, wireline operated

Magnetic Orientation ToolBorehole Geometry / CaliperGyro Orientation Tool

MSCTFTCRFT

FSFMFDNMudlogDTS

GPITBGTGCT

HydraulicSurveys

Orientation

Sampling

GFZ, OSG, J.Kück

Wireline Logging Methods -4-

Type Method Code

Casing Collar LocatorMulti Finger CaliperCement Bond LogCement Evaluation ToolSonic Casing InspectionMagnetic Casing InspectionFree Point Indicator ToolBack-Off ServicesCutter & Colliding ToolsElectromagnetic Retrieval ToolCasing Perforation

CCLMFCCBLCETUSIDMAGFPIT

CERTGuns

TechnicalServices

GFZ, OSG, J.Kück

Combination ofmethods / log parameters

- refines the interpretation -

&

- delivers new parameters -

GFZ, OSG, J.Kück

Lithology

Mineralogy

Alteration

Fracture detect.

Porosity

Structures

Fluid activity

Stress field

Gas detection

Core/Log Integr.

Technical

SG

RD

ensi

ty

NP

HI

Son

icR

esis

tivity

Mag

netic

sIm

age

logs

Cal

iper

Mud

Res

.F

low

Pre

sure

Dip

met

erS

eism

ics

Tem

pera

t.

Flu

id S

amp

Application

Logs

Logs and their applications

Gra

vity

Sid

ecor

es

Stress fieldC

alip

er

Sei

smic

sD

ipm

eter

Imag

e lo

gs

Son

ic

GFZ, OSG, J.Kück

total GR/telemetry

Sonic

SGR

MSUS

DIP

Length = 10 m

Combination of Logging sondesLogging Tool String

Combination of Logging sondesLogging Tool String

GFZ, OSG, J.Kück

total GR

Sonic

MSFL

Resistivity

Length = 18 m