Page 109 - The Petroleum System From Source to Trap

5. Applied Source Rock Geochemistry 103

' OXYGEN HYDROGEN ORGANIC WELL i HYDROCARBON SOURCE RE HYDROCARBON
INDEX INDEX CARBON DATA i POTENTIAL I F LECTANCE i INDICATIONS
AND TMAX i
DEnH I 1 I
, .
I j .::�. · i .::. :: I ; J� � t; !: � � rooo11 , .. loooo1 .��� :!;q ��� �I / ! w� � � ��� MUD ., .. :� ·1! ""'"
.... !I
. J
' 1 : , � Ill ;:: g � �, I I II I I OIL IOC:l�VAI R ��EYAL
I' " ' 0 i I i'TMAX · 'i' LOG OC · '
;:!
C
O
FEET :! :t o HTDROCARBON" .
*T �: oo11 ,.(S�T: :� � TOC 'l.WT '1 < 2 5 �!I : 2 � � � ' . li. WT ! S, t S , 'l"'· , � ':' ."' : ? � I
lll ll:l, t � U _1GU5 2;0 �Gij GAS s, .. ...
I
ji! ' S , VELD
'i
•
J
.
.
� I , I 11 ' , ,�,u� 1.5 � , I ':5 1 , : 215 I; I I I ,I . •
I
! , I I i il
'I
I
•
000 ' I
, J!j 500
2000
Li lj ij 1000
lOOO
-:;: I
.rooo
' : I IJ
1500
} I ' lil_
50011
I
- i- {
6000 . �
i 2000
! 1\
•
7000 ; ! .
0
r l
8000
9000
. . l1- I
� I'
. :!;·
:
-
j r
10000 i -
llOO i
I • r
. •
··- i . I - " .
12000
I i I
! I
llOOO
:
HOOO !
4500
!iOOO
:
iiOOO
5000
' I
S, ;HCS ALREADY IN ROCK S, ;HCS FROM KEROGEN PYROLYSIS. S3 ;CQ2 FROM KEROGEN PYROLYSIS.
Figure 5.4. Geochemical log for well I, showing immature and mature source rocks in the Upper and Lower Cretaceous
(see Tables 5.1-5.3). Mud gas data were unavailable for this well.
II. High productivity indices (at 100-600 m and equivalent 0.5% for this unit). Because it is very thick, the
1820-2600 m) are an artifact of low S1 and S 2 values in Upper Cretaceous source rock still shows a high SPI of 15
rocks containing highly oxidized organic matter. t HC/m 2 . Variations in TOC and HI in the Upper Creta­
Well III is located about 80 km northwest of well I ceous source rock in this well are more obvious than in
(Figure 5.6). Sidewall cores are indicated by dotted bars, wells I and II and can be explained by local sea level fluc­
while ditch cuttings are indicated by solid bars. Only the tuations. Geochemical parameters on the logs in Figures
Upper Cretaceous potential source rock was penetrated 5.4-5.6 allow individual units to be correlated among
in this well. This unit is less oil prone than in wells I and these three wells, similar to conventional correlations
II, but it is approaching the onset of oil generation (R, using wireline logs and paleontology.