Neutrons as a multifunctional tool for geophysicists · Neutrons as a multifunctional tool for geophysicists Urszula Woźnicka Tomasz Zorski H. Niewodniczanski Institute AGH University

Neutrons as a multifunctional tool Neutrons as a multifunctional tool for geophysicistsfor geophysicists

Urszula Urszula WoźnickaWoźnicka Tomasz Tomasz ZorskiZorski

H. Niewodniczanski Institute AGH University of Science of Nuclear Physics, PAN and TechnologyKraków, Poland Kraków, Poland

3rd Workshop on Neutron Measurements, Evaluations and Applications

October 25-28, 2006, Borovets, Bulgaria

OurOur experienceexperience andand achievementachievement inin nuclearnuclear geophysicsgeophysics

TheThe Henryk Henryk NiewodniczanskiNiewodniczanskiInstituteInstitute ofof NuclearNuclear PhysicsPhysics

IFJ PANIFJ PANKraków, Kraków, PolandPoland

AGH University AGH University of Science and Technologyof Science and Technology

DeptDept. . ofof GeophysicsGeophysicsKrakówKraków, Poland, Poland

ProfessorProfessor Jan A. Czubek Jan A. Czubek –– nuclearnuclear geophysicistgeophysicistCloseClose cooperationcooperation: IFJ & AGH: IFJ & AGH

NUCLEAR GEOPHYSICSNUCLEAR GEOPHYSICS

Theoreticalresearch

Field andlaboratory

measurements

Monte Carlosimulations

Semi-empiricalcalibration methodfor neutron tools

Sigma-a laboratorymeasurement

methodFLUKA, MCNP

1935-1995

SpeachSpeach outlineoutline

Borehole tools,Measurements,Comprehensive

interpretation

Borehole tools,Measurements,Comprehensive

interpretation

SpectrometricNeutron-Gamma

Logging Tool

SpectrometricNeutron-Gamma

Logging Tool

Neutron-Neutron Logging Tool

Neutron-Neutron Logging Tool

Neutron LifetimeLogging Tool

Σa

Neutron LifetimeLogging Tool

Σa

ComplexComplex NuclearNuclear ToolToolCxNTCxNT

BoreholeBorehole geophysicsgeophysics

Measured valuesMeasured values

•• ReRessistivityistivity, LLD, LLS , LLD, LLS

••Transit interval time, DTTransit interval time, DT

•• Bulk density, RHOB Bulk density, RHOB

•• Neutron porosity, NPHINeutron porosity, NPHI

•• Natural radioactivity, GRNatural radioactivity, GR

(…)(…)

Well logsWell logs

•• ElectricElectric

•• AcousticAcoustic

•• NuclearNuclear

(…)(…)++

LaboratoryLaboratoryanalysisanalysisofof thethe corecore

sonde

borehole

rock

CComprehensiveomprehensive interpretation of well logsinterpretation of well logs

Input data:measurements (logs)

in the boreholealong the depth

Output results:lithology, porosity,

saturation fluidsof the rock


For For exampleexample: : naturalnatural gamma gamma measurementmeasurement

kmink

kminlimlimsandsandclclww VVVVS γ∑+γ+γ+γ+γφ=γ

Nat

Nat

. . γγde

tect

orde

tect

orPorePore

spacespaceClayClay

mineralsmineralsSandSand--stonestone OtherOther mineralsminerals

SpectrometricSpectrometricNeutronNeutron--Gamma Gamma

LoggingLogging ToolTool

MeasurementMeasurement methodmethod

ToolTool calibrationcalibration

-- CalibrationCalibration FacilityFacility

-- Monte Monte CarloCarlo simulationssimulations((librarylibrary problemsproblems))

SpectrometricSpectrometric NeutronNeutron--Gamma Log SNGGamma Log SNG

γXXnX 1AZ

*1AZ

AZ +→→+ ++

γ fromradiativecapture

Slowndownneutron

XAZ

1000

10000

100000

20 30 40 50 60 70 80 90 100

Piaskowiec Radków

Wapień Józefów

Piaskowiec Mucharz

H (1,71-2,35 MeV)

Si (2,67-5,03MeV)

Ca (5,25-6,64MeV)

Fe (6,85-10MeV)

Fe: 7

,631

MeV

7

,646

MeV

Ca:

6,4

18M

eV

H: 2

,223

MeV

Si:3

,539

MeV

Si:4

,934

MeV

Cou

nts

rate

[pul

se/6

00 s

]

Number of channel

Sandstone RadkówLimestone JózefówSandstone Mucharz

Neutronsource

BGO

CalibrationCalibration ofof thethe NeutronNeutron--Gamma Gamma ToolTool

Element Eγ [MeV] Window ΔEγH 2.22 2.001 – 2.521Si 3.54, 4.93 2.625 – 5.228Ca 6.42 5.332 – 6.789Fe 7.631, 7.645 6.893 – 8.975

Fe Ca, Si, H, :el4

1

elpom

elel0

elchem

ii∑=

=+=

i

ii IbbC

Measurementin calibrationblocks of knownconcentration ofH, Si, Ca, Fe

Multiplelinearregression

gamma gamma countscountsconcentrationconcentration

General view of Calibration Facility site during calibration measurements. The wood board covers two big pools where all calibration blocks are stored.

The pool contains 18 natural rocks standards for basic neutron tool calibration (4 limestones, 4 sandstones and 1 dolomite - each of them for two hole

diameters).

CalibrationCalibration FacilityFacility inin thethe WellWell LoggingLogging BaseBase

Zielona Góra, Zielona Góra, PolandPoland

PProprietorroprietor::Geofizyka Kraków Geofizyka Kraków CompanyCompany& AGH & AGH UniversityUniversity

Experimental Tool Calibration:Basic neutron porosity/lithology

calibration,• Natural gamma calibration

(API, K, U, Th),• Vertical response tool analysis.

Artificial rock models for a determination of the Vertical Response Function for nuclear tools. The models areconstructed of the specially prepared ceramic bricks and consist of the set of thick and thin layers. The dimension of the single brick is 30 x 30 x 7.5 cm. Three porosities: 16, 25 and 60% are available for these models. The models are located inside the 3 m deep concrete pool filled always by water. These models were constructed by the AGH University.

CalibrationCalibration FacilityFacility inin thethe WellWell LoggingLogging BaseBase

ModelingModeling ofof thethe the spectrometric the spectrometric nneutroneutron--gamma well logging probe, gamma well logging probe,

SOSO--55--9090--SNSN Aluminium

Steel

Lead

Am-Besoure

BGOdetector

Concrete base

Hole

Rockmodel

Water pool n-gamma probe

(SO-5-90-SN type)

Detector (BGO)

Am-Besource

Monte Monte CarloCarlo CalibrationCalibration ofof thethe NeutronNeutron--Gamma Gamma ToolTool

BM2Mo2Jo2Li2Pi2

Mu2 Br2

Ra2Ze2

0 1 2 3 4 5

C-Fe-chem [wt.%]

0

1

2

3

4

5

C-F

e-M

CN

P [

wt.%

]

95% p.ufności

R2 = 0.973(9 punktów)

R2 = 0.988(21 punktów)

CalibrationCalibration ofof thethe NeutronNeutron--Gamma Gamma ToolTool

ExperimentalExperimentalcalibrationcalibration pointspoints

NumericalNumericalcalibrationcalibration pointspoints

Cl(n,γ)Cl - gamma ray lines

0

5

10

15

20

25

30

0.08

1.14

1.60

1.96

2.47

2.68

3.00

3.56

4.54

5.01

5.58

5.90

6.11

6.62

7.41

8.58

Eγ (MeV)

I γ (p

er 1

00 c

aptu

res)

endf60Cl(n,γ)Cl - gamma ray lines

0.001

0.01

0.1

1

10

100

0.09 0.

3

0.44

0.53

0.66

0.83

0.96

1.13 1.

5

1.7

1.95

2.11

2.28

2.49

2.68

2.87

3.14

3.36

3.59

3.83

4.13

4.42

4.73

5.11

5.78

6.95

Eγ (MeV)

I γ (p

er 1

00 c

aptu

res) ACTIA

Problems with the ENDF libraries


A l(n ,γ )A l g a m m a -ra y lin e s

0.001

0.01

0.1

1

10

100

1000

10000

0.03

1.17

1.72

2.27

2.55

2.73

3.02

3.30

3.64

3.82

4.04

4.24

4.58

4.87

5.21

5.46

5.88

6.39

6.89

E γ (M e V)

I γ (p

er 10

0 cap

ture

s)

ACTIA1.779 M eV (d elayed)

Problems with the ENDF libraries


NeutronNeutron--Neutron Neutron LoggingLogging ToolTool

Neutron Neutron fieldfield inin rock mediumrock medium

CalibrationCalibration ofof thethe n n –– n n tooltool-- SemiSemi--empiricalempirical methodmethod-- MonteMonte--CarloCarlo simulationsimulation

ThermalThermal neutron neutron absorptionabsorption crosscross sectionsection-- LaboratoryLaboratory measurementmeasurement-- BoreholeBorehole neutron generatorneutron generator-- NNTE NNTE -- tooltool

NeutronNeutron--Neutron Neutron ToolTool

Neutron Neutron sourcesourcee.ge.g. . AmBeAmBe

Neutron Neutron detectorsdetectors

IsolinesIsolines ofofthethe neutron neutron fieldfield

NeutronNeutron--Neutron Neutron ToolTool: : DetectorDetector responseresponse

similarly:

BoreholeBorehole geometry:geometry:

( ))(

,,

GNPf

PLfI apapmapth

=

Σ=

Źródłoneutronowe

Lm

DetektorLmap

( )P,,LfI

ree

LLPQr

amth

dL/rsL/r

dsath

Σ=

−−Σπ

=φ−−

224)(

Neutronsource

Detector

Lm

HomogenousHomogenous infiniteinfinite medium:medium:

GGeneraleneral NNeutron eutron PParameterarameter

Tool

resp

onse

General Neutron Parameter

Por

osity

A B C

A, B, C - Borehole diameter

CalibrationCalibration ofof thethe NeutronNeutron--Neutron Neutron ToolTool

GNPGNP::-- slowingslowing downdown lengthlength-- diffusiondiffusion lengthlength-- absorptionabsorption crosscross sectionsection((i.ei.e.: .: integralintegral neutronneutron

parametersparameters))

NeutronNeutronmeasurementmeasurement

GeologicalGeologicalparameterparameter


ProceduresProcedures

SimulationSimulation measurementsmeasurementsMonte Monte CarloCarlo

RealReal measurementsmeasurementsCalibrationCalibration FacilityFacility

NNTElogging-

l

water

block

concrete

Nucleartool

Water

Standardrock

Concrete

AnalyticalAnalytical solutionssolutions ofof thethe neutron transport neutron transport phenomenaphenomenainin a a boreholeborehole geometrygeometry

necessarilynecessarily not necessarilynot necessarily


TheThe importantimportant parameterparameter ofof thethe rock medium rock medium indispensableindispensable for for thethe geologicalgeological interpretationinterpretation

ofof thethe neutron neutron –– neutronneutron tooltool::

ThermalThermal neutron neutron absorptionabsorption crosscross sectionsectionofof thethe rock rock matrixmatrix

ΣΣaa

Laboratorymeasurent

on core samples

LaboratoryLaboratorymeasurentmeasurent

on on corecore samplessamples

in situ:Neutron

Lifetime Log

inin situ:situ:NeutronNeutron

LifetimeLifetime LogLog

in situ:Improved

neutron-neutron toolNNTE

inin situ:situ:ImprovedImproved

neutronneutron--neutron neutron tooltoolNNTENNTE

Rocksample Moderator Cadmium

surrounding

ΣΣaa LaboratoryLaboratory measurementmeasurement … …



…… usingusing a a pulsedpulsed neutron generatorneutron generator

((Czubek’sCzubek’s methodmethod))

Neutron Neutron lifetinelifetine logginglogging::boreholeborehole pulsedpulsed neutron generatorneutron generator


source: http://www.spwla.org/library_info/glossary/

http://www.spwla.org/library_info/glossary/

NeutronNeutron--neutron neutron thermalthermal--epithermalepithermal well logging well logging tooltoolNNTENNTE

Nearepithermaldetector

źródło Am-Be

Farepithermaldetector

Nearthermaldetector

Prototype: AGH University and Geofizyka Kraków Company

Idea Idea ofof thethe ComplexComplex NuclearNuclear ToolTool CxNTCxNT

During last three years we made field measurements using the NNTE, SNG and SNA methods, working as the separate experimental tools.

These works confirmed that expected valuable geological information can be retrieved from this kind of measurement.

It became clear that the new complex tool must be made because of the optimisation of the time service.

Thin – bedded, shaly – sand gas formation in Carpathian Foredeep, Poland was place of experiments.

Cable (7 wires, 5000 m)

Digital data transmission block (at least 25 channels)

Spectral Gamma-Ray Log SGRSGR (BGO, 0.2 – 2.8 MeV)

3He Far detectors (thermal/epithermal)

3He Near detectors (thermal/epithermal)

AmBe neutron source (6 – 18 Ci)

Spectral Neutron-Gamma SNGSNG (BGO, 0.4 – 8 MeV)

Neutron Activation SNASNA (BGO, 0.2 – 2.8 MeV)

K, U, Th

Σa, porosity

Σa, porosity

Si, Ca, FeCl, S

Al

NNTENNTE

DEP

TH [

m]

QUARTZ

CLAY

POROSITY(WATER, HYDROCARBONS)

LIMESTONE


Each log is described by the equation which joint porosity, satuEach log is described by the equation which joint porosity, saturation ration and various mineralogical components with the tool response:and various mineralogical components with the tool response:

( ) miVaMLn

jjiji ,...,1

1== ∑

=

VolumeVolume fractionfractionofof thethe jj--thth componentcomponent

MeasuredMeasured signalsignalofof thethe ii--thth tooltool

SolutionSolution ofof thethe set set ofof equationsequations MLMLii ::

Vj : Φ – porosityS – saturation (water, hydrocarbons … )Vm – mineral components (rock marix, clay … )


Documents

Neutrons as a multifunctional tool for geophysicists · Neutrons as a multifunctional tool for geophysicists Urszula Woźnicka Tomasz Zorski H. Niewodniczanski Institute AGH University