Formation Evaluation and Well Log Correlation

5/22/2018 Formation Evaluation and Well Log Correlation

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Formation evaluation and well logcorrelationS W A P N I L P A L

I M T G E O L O G I C A L T E C H N O L O G

I N ! I A N I N S T I T " T E O F T E C H N O L O G # O O # $ E E


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OverviewWell log de%inition and it& im'ortance

Fundamental& o% (ualitative and (uantitative log inter'retation

Formation evaluation wit) well log&

Proce&&ing and inter'retation o% well log data

Conclu&ion


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Well log

The continuousrecording of ageophysical parameteralong a boreholeproduces ageophysical well log.

The value of themeasurement isplotted continuouslyagainst depth in thewell.


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Basic Logs Tools and theirMeasurements

Gamma Raylog


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Calliper log


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lectrical log


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!ensity log


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"eutron log


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#etrophysical $nterpretation

%ualitative assessment %uantitative assessment

&ssessment of

reservoirproperties' (uid typeform log pattern.

"umerical estimation

ofreservoir propertiesvi). * of oil' water etc.


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Basic steps for +uic, loo,evaluation

R-C

Reservoir

"on/

Reservoir

0ydrocarbo

n bearing

Water

bearing

Gas

bearing

-il

bearing


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%ualitative $nterpretation

$denti1cation of Reservoir or "on/reservoir

Low gamma ray(Reservoir rock)


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$denti1cation of hydrocarbon or water bearing )one


Low gamma ray +High Resistivity value


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Low gamma ray +High Resistivity value +

Large deviation in RHOB and NPHI value(crossover region)

$denti1cation of oil or gas bearing )one


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Gas bearing )one

-il bearing )one

Water bearing )one


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%uantitative $nterpretation

stimation of e2ective porosity 3permeability.

stimation of volume of clay fraction. stimation of hydrocarbon saturation. !etermination of the depth and thic,ness

of net pay.

stimation of reserves of hydrocarbon.


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stimation of porosity


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!epth4m5 6sh #0$! #0$dc #0$" #0$nc

e2ective4Gas5

789: :.;7: :.=;?;?? :.7:> :.7;


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!epth4m5 6sh #0$! #0$dc #0$" #0$nc

e2ective4Gas5

78;: :.>@>9 :.:;>?;9 :.@> :.:8>?9= :.:?>?


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!epth 4m5 6sh #0$! #0$dc

=:=< :.=@>?9= :.=;?;?? :.=7=; :.=>:>:> :.7??

=:@7 :.@9=7:< :.=9=9=9 :.7?;9

=:@< :.==@>?9 :.=>:>:> :.=:=@7@

=:@> :.==@>?9 :.=>:>:> :.=:=@7@

=:@; :.78;@>? :.=@>@>9 :.7?8;7@

water !earing "one


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stimation of hydrocarbon saturation

#an not !e measured directly !ut in$erred $romdetermination o$ %&'R &'*R&'ION (w) $romRI'II', and POROI', logs-

w. /raction o$ 0ore s0ace occu0ied !y water- h . /raction o$ 0ore s0ace occu0ied !y

hydrocar!on-

Ah Aw 7

-il

Water


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&rchieDs e+uation


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Calculation of formation water resistivity E Rw

Fsing Inverse &rchie1s e2uation

Rt

0.95

0.7

0.1

0.8

0.9

0.7

0.7

0.7

0.85

Rw

0.073837

0.037128

0.0045

0.054332

0.052893

0.054406

0.047541

0.047541

0.047488

Depth

2025

2028

2029

2030

2031

2034

2035

2036

2037

Water bearing )one

Rw= 0.05' this is used in &rchieDs e+uation to calculate watersaturation in oil and gas bearing )one


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Depth

1940

1945

1948

1950

1953

1957

1958

1970

1972

1974

1976

1978

1980

1982

1984

PHId

0.2787

88

0.4181

82

0.3818

18

0.424242

0.4848

48

0.3272

73

0.2666

67

0.2363

64

0.2121

210.2727

27

0.2727

27

0.2545

45

0.2727

270.2909

Rt

0.65

15

35

48

33

0.9

0.85

1

1.5

2

4

2.9

3

1.2

0.8

Sw

(Archie)

0.99484

3

0.13806

2

0.09899

10.07607

6

0.08028

3

0.72020

1

0.90950

9

0.94602

9

0.86070

70.57975

1

0.40994

6

0.51584

7

0.47336

50.70167

Calculation of water saturation in oil and gas )ones

78@: 789: 78: 78;: 78?: 788::

:.=

:.9

:.>

:.?

7

7.=

!epth 4m5

AwE water saturation


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Gas bearing )one

-il bearing )one

Water bearing )one

78=: 789: 78>: 78?: =::::

:.=

:.9

:.>

:.?

7

7.=

!epth 4m5

AwE water saturation

0urray

-ilfound

6Hs%uantitative $nterpretation


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Conclusion

Well logs contains ,ey information about the formationdrilled in di2erent petro/physical measurements. i.e.

#rospective )ones of hydrocarbon. Reservoir type and thic,ness. stimation of #orosity' permeability. Iluid type present in the pores and saturation level.

'o economically esta!lish the e3istence o$0roduci!le hydrocar!on reservoirs (oil 4gas)-


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References

Archie II lectrical conduction in hydrocarbon bearing )one. 4n.d.5. $nRoc, #hysics 46ol.@>5.Archie III lectrical conduction in shaly sand. 4n.d.5. $n Roc, #hysics 46ol.75.Archie!" #$w lectrical conduction in clean' water bearing roc,. 4n.d.5. $n

Roc,physicsH0istory 46ol. @>5.H$##i%&rt'. 4n.d.5. Log $nterpretation Charts. H Rider. 478875. The Geological $nterpretation of well logs. GlasgowEWhittes #ublishing.(1989). *pe h'#e we## #'++i+ Iterpret$ti'. TeJasE Achlumberger

Wireline 3 Testing.Serr$, *. 478?95. Iundamentals of well log interpretation. &msterdamElsevier.


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Than, you

Formation Evaluation and Well Log Correlation

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