neutron log tools and characteristics

7/25/2019 Neutron Log Tools and Characteristics

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Asriza

Dimas

Almer

NEUTRON LOG


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OUTLINE Definition.

Types

Units & Presentation Theories of measurement

Tool and Characteristics

Quantity and Quality Using on Neutron Porosity


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NEUTRON LOG Neutron log is a porosity log that measured the concentration of

hydrogen ion in rocks formation

Used for determined the total porosity of rocks, regardless of

whether the pores filled by hydrocarbons and water in a formation


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NEUTRON LOG

Neutron logs all emit neutrons

from a source at the bottom of

the tool. (Americium atau

Berillium), that emitted to rocks

formation


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THE PRINCIPLES O NEUTRON LOGGING

Neutron source emits a continuous flu of high!energy

neutrons"

#ollisions with formation nuclei reduce the neutron energy

!thereby slowing it down, mostly in hydrogen" Neutrons are slowed sufficiently to be captured by

nuclei, at thermal energy le$els (approimately %"%&' e)


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*+ -.N#./+0 12 N+U-1N /133.N3

Neutron capture results in an emission of gamma rays"

Capturing nuclei become excited and emit gamma

rays The detector will captured the gamma radiation, and

if the amount of gamma rays per second quite bit

high so the porosity will very low


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EL!STIC !N" INEL!STIC SC!TTERING


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NEUTRON LOG TOOLS !N"

CH!R!CTERISTICS


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GAMMA A! N"UT#N $#G %GNT

.s the first generation of neutron log" .t use the

basic measurement using the principle of neutron

logging" .gnore bore hole diameter, only source

and detector with no configuration


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'(D")A$$ N"UT#N P##'(T! %'NP

borehole effects minimized

automatic corrections

applicable to empty holes

4 -ugosity and mudcake effects


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C#MP"N'AT"D N"UT#N $#G %CN$

Neutron 0ource emitting , and causing

scattering of gamma ray" wo detector

detect with distance to gi$e a proper

measurement with less error


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C#MP"N'AT"D N"UT#N $#G %CN$

thermal neutron detection instrument

wo detectors minimize borehole effects

ertical resolution ! & ft

-adial in$estigation f(porosity) No porosity ! 5ft"6*igh porosity less

#ased or openhole

0tatistical in nature, logging speed &%!7% fpm

#an be run with other logs


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DUA$ N"UT#N $#G %DN$

he 0ame with #N/, gi$es proper

measurement " -adial scattering cause

more effect on gamma radiation from all

sides


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SNP #S CNL


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$U!NTIT% !N" $U!LIT% USING ON

NEUTRON POROSIT%


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QUANT(T! U'(NG

orosity formula 8

with 0igma 9 true porosity 6 a : B 9 constant 6 N 9 Neuron read

o determine the porosity $alue of formation


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&e can 'etermine

(orosit) of formation

*ith gra(h +


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G!S EECT TO NEUTRON LOG

3as content $ery low

hydrogen, so the

neutron log turn to right

etreamly


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NEUTRON LOGGING APPLICATIONS

Neutron tools are used primarily to determine8

orosity, usually in combination with the density tool

3as detection, usually in combination with the density tool, but alsowith a sonic tool

0hale $olume determination, in combination with the density tool /ithology indication, again in combination with the density log and;or

sonic log 2ormation fluid type"


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$U!LIT% USING

o determine the litology, we ha$e

to knowing distribution of

hydrogen in a formation *ydrogen that detect on neutron

log are hydrogen on hydrocarbon

and hydrogen on water

/ecture notes for + 7


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CONCLUSION

Neutron log measure porosity of the formation

Neutron log is an active sensor, its emit neutron and detect

gamma rays

Neutron log can be used both open and closed hole for some

equipment like CNL To determine formation, usually neutron log combine with other

log


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REERENCE

+ngler, "=", &%5&, /ecture notes for + 7ournal, p"5&!7

neutron log tools and characteristics

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