Case History

3D PETROLEUM SYSTEM MODELLING

INTEGRATED ANALYTICAL TECHNIQUES FOR A GEOCHEMICAL STUDY

Fig.1 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

1

3D PETROLEUM SYSTEM MODELLING

Sometime, conventional geochemical techniques (GC, GC-MS and Isotopes) cannot be enough to completely describe the “genetical” features of oil samples. Consequently, only limited information on their origin and maturity can be extracted from the classical data set based on such techniques. An example is reported in the next slides where a case of a well with four oils levels is presented. Fig.2 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

2

3D PETROLEUM SYSTEM MODELLING

Example A case study of an exploration well The aim of a classical geochemical study performed on oil samples is to define the oil origin and maturity. Moreover, if necessary, hydraulic continuity (both lateral and vertical) from different oil levels can be object of the study too. Fig.3 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

3

3D PETROLEUM SYSTEM MODELLING

Oils characterization Data set Sample no.

Date

4,02 2,04 2,01 1,01

06/09/2002 04/09/2002 04/09/2002 03/09/2002

Bottle Pressure Chamber Depth Sample Volume Destination no. barg no. m nature cc PT 1183 TS 11214 PT 2067 TS10910

120 90 120 120

MRSC 187 MPSR 1045 MPSR 988 MRMS 1049

1773,5 1790,5 1712,3 1865,6

Oil Oil Oil Oil

410 230 410 420

Agip Milan Agip Milan Agip Milan Agip Milan

MDT run4 MDT run2 MDT run2 MDT run1

Fig.4 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

4

3D PETROLEUM SYSTEM MODELLING

Oils characterization – Classical Analytical Procedures - MPLC fractionations in SAT, ARO, RES and ASF (preparative) - GCMS analysis of SAT and ARO fractions (origin and maturity) - Carbon Isotopic analysis of SAT, ARO, RES and ASF fractions (origin) - GC-Fingerprint of whole oils (hydraulic communications in the reservoir)

Fig.5 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

5

3D PETROLEUM SYSTEM MODELLING GC-MS analysis 1712.3 m (PT2067)

1790.5 m (TS11214)

Abundance

Abundance TIC: 7955HCS.D

2000000

TIC: 7957HCS.D

1800000

1800000

1600000

1600000

1400000

1400000

1200000

1200000

1000000

1000000

800000

800000

600000

600000

400000

400000

200000

200000 10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

Time-->

10.00

Abundance

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

Abundance

Time-->

Ion 191.20 (190.90 to 191.90): 7955HCS.D

Ion 191.20 (190.90 to 191.90): 7954HCS.D

190000

95000

180000

90000

170000

85000

160000

80000

150000

75000

140000

70000

130000

65000

120000

60000

110000

55000

100000

50000

90000

45000

80000

40000

70000

35000 30000

60000

25000

50000 40000

20000

30000

15000

20000

10000

10000

5000

0 25.00

30.00

35.00

40.00

45.00

50.00

0 25.00

55.00

1773.5 m (PT1183)

Time-->

Time-->

30.00

35.00

40.00

45.00

50.00

55.00

1856.6 m (TS10910)

Abundance

Abundance TIC: 7954HCS.D

1800000

TIC: 7956HCS.D

2000000 1800000

1600000

1600000

1400000

1400000

1200000

1200000

1000000

1000000

800000

800000

600000

600000

400000

400000

200000

200000

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

Time-->

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

Time--> Abundance

Abundance Ion 191.20 (190.90 to 191.90): 7954HCS.D

Ion 191.20 (190.90 to 191.90): 7957HCS.D

95000 90000

80000

85000

75000

80000

70000

75000

65000

70000

60000

65000

55000 60000

50000

55000

45000

50000 45000

40000

40000

35000

35000

30000

30000

25000

25000

20000

20000

15000 15000

10000

10000

5000

5000 0 25.00 Time-->

0 30.00

35.00

40.00

45.00

50.00

55.00

30.00

35.00

40.00

Time-->

3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

45.00

50.00

55.00

Fig.6

6

3D PETROLEUM SYSTEM MODELLING

Oils Isotopic Characterization

-24,00

-25,00

Carbon Isotopic Ratio (Sat. v s. Aro.)

-26,00

1773,50

-28,00

1865,60

-27,00

13

1712,30

-29,00

1790,50

Carbon Isotopic Ratios in Oil Fractions -27,50

-30,00

AROM.

-31,00

-28,00

-32,00

13

-32,00

δ C

δ C ARO.

-27,00

-31,00

-30,00

-29,00

-28,00

δ

13

-27,00

-26,00

-25,00

-24,00

Legend: 1 = Saturates 2= Aromatics 3= NSO 4= Asphaltenes ASPH

SAT.

-28,50

C SAT

NSO

-29,00

1773,50 1712,30

-29,50

1865,60 1790,50 -30,00 1

2

3

Carbon Stable Isotopes Analysis shows homogeneous results which indicates a common origin (i.e. same organic matter and source rock) 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

4

Fig.7

7

3D PETROLEUM SYSTEM MODELLING

GC-MS and Isotopic analyses Conclusions

Based on GC-MS and Isotopic analyses, all the oils are similar one to each others and belong from the same source rock. The oils appears to be generated by a marine carbonate source rock deposed in a anoxic depositional environment. Maturity can be located in the first part of the oil window (Ro eq. about 0.8-0.9%). Fig.8 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

8

3D PETROLEUM SYSTEM MODELLING

GC-Fingerprint analysis

A/B 3.5

o/p

* * * * * H I E R A R C H I C A L

C L U S T E R

C/D

3

A N A L Y S I S * * * * * *

2.5

k/l

G/H

2

Dendrogram using Average Linkage (Between Groups)

1.5

Rescaled Distance Cluster Combine C A S E Label

Num

1773.5 QC

2

1773.5

3

1712.3

1

1790.5 QC

4

1790.5

5

1865.6

6

i/j

I/J

1

1712.3

0 5 10 15 20 25 +---------+---------+---------+---------+---------+

0.5

1773.5 QC 1773.5

0

1790.5 QC

g/h

K/L

1790.5 1865.6

a/b

M/N

Y/Z

Q/R U/V

S/T

Apparently, there are three vertically separated levels in the studied well Fig.9 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

9

3D PETROLEUM SYSTEM MODELLING

This is what can be said on the case under examination if only conventional techniques for the oil characterization are applied. In the following, results of some “less conventional” techniques applied to the oils (Light Hydrocarbons, Asphaltenes Tmax, Phenols and GC-MS-MS), with the aim to go deeper in the oil characterization, are shown.

Fig. 10 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

10

3D PETROLEUM SYSTEM MODELLING

Oils characterization – Unconventional Analytical procedures -Light Hydrocarbons analysis of whole oils (origin and maturity) - Phenols analysis of oils (migration) - Asphaltene Tmax analysis (maturity) - GC-MS-MS of saturates for specific age related biomarkers investigation (constrain the age of the source)

Fig. 11 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

11

3D PETROLEUM SYSTEM MODELLING Light Hydrocarbons Thompson Diagram

Ctemp

60.0000

0.1200

Supermature 0.1100 q/t (2,2-DMP+3,3-DMP/3-EP+2,3-DMP+2,4-DMP)

50.0000

Heptane value

40.0000 Aliphatic curve

30.0000

Mature 1865.6 m 1773.5 m 1790.5 m1773.5 QC 1712.3m mQC

Normal

Aromatic curve

20.0000 Biodegraded

1790.5 m QC 1865.6 m 1790.5 m

0.1000

0.0900 1773.5 m QC 1773.5 m 1712.3 m 0.0800

0.0700

10.0000 0.0600

0.0000 0.0000

0.5000

1.0000

1.5000

2.0000

2.5000

3.0000

3.5000

4.0000

4.5000

0.0500 105.0

5.0000

107.0

109.0

111.0

113.0

Isoheptane value

Mango Parameters

117.0

119.0

121.0

123.0

125.0

Mango Parameters

100000

250000

1790.5 m

1790.5 m

90000

1790.5 m QC

1790.5 m QC 1773.5 m 1865.6 m

80000

1773.5 m

200000

1865.6 m

70000

1773.5 m QC

1773.5 m QC 1712.3 m 60000

150000

50000

1712.3 m

P2

P3

115.0 Ctemp (2,4/2,3-DMP)

40000

100000

30000

20000

12

50000

10000

0 0

50000

100000

150000

200000

P2+N2

250000

300000

350000

0

0.5

0.55

0.6

0.65

0.7

0.75 N2/P3

3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

0.8

0.85

Fig. 12 0.9

0.95

1

3D PETROLEUM SYSTEM MODELLING

Light Hydrocarbons

- there are two groups of oils whose are different for both maturity and “kitchen” of the source rock; - not necessarily this means that there are two different sources in terms of age and/or organic matter faces.

Fig. 13 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

13

3D PETROLEUM SYSTEM MODELLING

Phenols and Asphaltenes Tmax analyses

Asphaltene T max was determined on two oil samples, each one representative of the two “groups” highlighted by the Light hydrocarbons analysis. Both the oils show exactly the same T max! 440°C …. and, consequently, the same maturity! Similarly, Phenols analysis was performed on the same samples. The results, expressed as Migration Molecular Index (MMI) are: 1.12 and 2.13. Indicating two different migration pathways from the sources to the reservoirs.

Fig. 14 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

14

3D PETROLEUM SYSTEM MODELLING

GC-MS-MS of saturates Taking into account the age of the possible sources as well the stratigraphic sequence of the study area, some specific agerelated biomarkers were investigated. In particular, because Triaromatic Dinosteroids were proved to be absent in samples coming from Permian sources while they were found in hydrocarbons extracted from sources younger than Permian and older than Carboniferous, particular attention was focused in searching for these compounds. Fig. 15 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

15

3D PETROLEUM SYSTEM MODELLING

GC-MS-MS of saturates 2a & 3b-Methyl-24-EthylSteranes 4a-Methyl-24-EthylSteranes

DINOSTERANES

Devonian Oil

Studied Oil

Fig. 16 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

16

3D PETROLEUM SYSTEM MODELLING

Consequently, the fact that no Triaromatic Dinosteroids were detected in the oils, was used as an indication that Permian-Carboniferous sources should be considered as the most suitable candidates to the generation of the oils themselves.

Fig. 17 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

17

3D PETROLEUM SYSTEM MODELLING

Oil characterization Conclusions A main oil family was recognized to be responsible for the four studied oils. A mature, marine carbonate source rock, probably Permian-Upper Carboniferous in age, is the most suitable source. Nevertheless, some small but significant differences, both in terms of maturity and source rock dependent parameters, between the two shallower oils and the deeper ones were highlighted. Two hypothesis can be suggested to explain these differences .....................................................................

Fig. 18 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

3D PETROLEUM SYSTEM MODELLING

Oil characterization a) there is a single source rock in terms of age and organic matter as suggested by biomarkers and isotopes, but physically separated into two different kitchens (source dependent light HC’s and Phenols), one more deep and more mature than the other (maturity dependent Light HC’s); b) there are two different source rocks, one younger and less mature (mainly responsible for asphaltenes Tmax, isotopic and biomarker data) and another one, older, deep seated and very mature (depleted in biomarkers and asphaltenes). This second source has generated a light oil which has mixed with the former one modifying drastically its light HC’s fraction and introducing all the elements of diversity discussed before. Depending on the mixing between the two oils, it is also possible to explain the differences in maturity between the shallower and the deeper oils. Fig. 19 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

18

3D PETROLEUM SYSTEM MODELLING

Oil characterization

Considering the two hypothesis already proposed about the origin of the oils, the Permian-Carboniferous sequence should be considered as the only single source but separated into two different kitchens at slightly different maturity (hypothesis a) or, at least, the younger co-source in case of a multiple source origin (hypothesis b). Fig. 20 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

19

3D PETROLEUM SYSTEM MODELLING

When available rock samples can be used for a source rock evaluation study aimed to select samples suitable to perform a “direct” oil-source rock correlation

Fig. 21 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

20

3D PETROLEUM SYSTEM MODELLING

Source rock evaluation CASPIAN SEA - BLOCK XI - 5a WELL: KALAMKAS 1

Exploration & Production Division

GEOCHEMICAL LOG Stratigraphy

TOC

700 P

F

G

S2

700 VG

P

F

HI

700

G

III

VG

II

TMAX

700

I

IMM

M

Ro

700

VM

IMM

M

V M

LOWER CRETACEOUS

?

Depth (m)

UPPER JURASSIC

MIDDLE JURASSIC

900

900

900

900

900

1100

1100

1100

1100

1100

1300

1300

1300

1300

1300

1500

1500

1500

1500

1500

1700

1700

1700

1700

1700

1900

1900

1900

1900

1900

2100

2100

2100

2100

2100

2300

2300

2300

2300

2300

L. JURASSIC TRIASSIC

ASSELIAN

ASSELIAN (Carb.) CARBONIFEROUS

Serie1

Serie1

2500 (%)

F= Fair

G= Good

VG= Very Good )

1.0

2.0

3.0

4.0

5.0

0

(kg HC/ton of rock)

( III= Type III

II= Type II

2500

2500 0.0

I= Type I )

(IMM= Immature

200

400

600

800

1000

400

420

440

(mg HC/g TOC)

M= Mature

Caved Vitrinite

Serie1

Serie1

2500 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

LEGEND (P= Poor

Indigenous Vitrinite Vitrinite "B"

T.D. 2360

VM= Very Mature)

460

(°C)

480

500

Oxidated Vitrinite

2500 0.1

0,55 1.0 1,35

10.0

(%)

MARCH 2003

Fig. 22 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

21

3D PETROLEUM SYSTEM MODELLING

S2 vs T.O.C.

100.0

Poor

Very Poor

Fair

Good

1000

Very Good

HI vs Tmax

immature

oil zone

gas zone

Ro 0,5

Very Good

Type I

800

MATURITY PROFILE

Fair

2,0

Poor

1.0

0,5

LOWER CRETACEOUS UPPER JURASSIC MIDDLE JURASSIC

600

Type II

QUATERNARY- TERTIARY

Indigenous Vitrinite

LOWER JURASSIC TRIASSIC

Vitrinite "B"

PERMIAN (ASSELIAN) PERMIAN (ASSELIAN Carbonates)

Caved Vitrinite

CARBONIFEROUS 400

Oxidated Vitrinite

500

Ro 1,35

200

LOWER JURASSIC

0

MIDDLE JURASSIC

?

Type III

TRIASSIC

LOWER CRETACEOUS

0.1

UPPER JURASSIC

UPPER CRETACEOUS

Good

HYDROGEN INDEX (mgHC/g TOC)

LOWER CRETACEOUS

4, 0

Very Poor

Petroleum Potential (Kg Hc/Ton of Rock)

10.0

PERMIAN (ASSELIAN)

1000

CARBONIFEROUS 0.0 0.0

0.1

0,2

0,5

2,0

1.0

10.0

0 380

100.0

Total Organic Carbon (T.O.C. %)

400

420

HI vs OI

1000

440

460

Tmax (°C)

480

500

520

Depth (m)

PERMIAN (ASSELIAN Carbonates)

Type I UPPER JURASSIC

1500 800

HYDROGEN INDEX (mgHC/g TOC)

MIDDLE JURASSIC Type II

2000

600

L. JURASSIC

LOWER CRETACEOUS UPPER JURASSIC

ASSELIAN (Carb.) CARBONIFEROUS

MIDDLE JURASSIC

400

LOWER JURASSIC

T.D. 2360

TRIASSIC

2500

PERMIAN (ASSELIAN) PERMIAN (ASSELIAN Carbonates)

0.1

0,55

1 1,35

2

10

Ro%

CARBONIFEROUS 200

Type III

0 0

100

200

300

TRIASSIC ASSELIAN

400

OXYGEN INDEX (mg Co2 /g. T.O.C.)

3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

Fig. 23

22

3D PETROLEUM SYSTEM MODELLING

Hydrocarbons were extracted from all the source rock intervals identified in the source rock study. The best oil-source rock correlation was obtained with Permian extracts as shown by the next slide

Fig. 24 3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

23

3D PETROLEUM SYSTEM MODELLING

DIRECT OIL-SOURCE ROCK CORRELATION Abundance

Abundance TIC: 8137TQ.D 550000

450000

400000

350000

TIC: 7956HCS.D

2000000

HC’s Extracted from Permian source

500000

1856.6 m (TS10910)

1800000 1600000 1400000 1200000

300000

1000000 250000

800000 200000

600000

150000

400000

100000

200000

50000

10.00

Abundance 10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

55.00

Time-->

60.00

Time-->

Abundance

Ion 191.20 (190.90 to 191.90): 7956HCS.D Ion 191.20 (190.90 to 191.90): 8137TQ.D

100000

14000

90000

13000 12000

80000

11000

70000

10000 9000

60000

8000

50000

7000 6000

40000

5000

30000

4000 3000

20000

2000

10000

1000 0

35.00

40.00

45.00

50.00

55.00

60.00

0 25.00

65.00

Time--> Abundance

35.00

40.00

45.00

50.00

55.00

Time--> Ion 217.20 (216.90 to 217.90): 8137TQ.D

8000

35000

6000

30000

5000

25000

4000

20000

3000

15000

2000

10000

1000 0 42.00

Ion 217.20 (216.90 to 217.90): 7956HCS.D

40000

7000

5000

43.00

44.00

45.00

46.00

47.00

48.00

49.00

50.00

51.00

52.00

0

53.00

Time--> Abundance

33.00

34.00

35.00

36.00

37.00

38.00

39.00

40.00

41.00

42.00

43.00

Time--> Abundance

Ion 218.20 (217.90 to 218.90): 8137TQ.D

8000

35000

6000

30000

5000

25000

4000

20000

3000

15000

2000

24

10000

1000 0 42.00

Ion 218.20 (217.90 to 218.90): 7956HCS.D

40000

7000

Time-->

30.00

Abundance

5000

43.00

44.00

45.00

46.00

47.00

48.00

49.00

50.00

51.00

52.00

0

53.00

33.00

Time-->

3D BASIN Eni Corporate University – Eni E&PMODELLING Division GROUP

34.00

35.00

36.00

37.00

38.00

39.00

40.00

Fig. 25 41.00

42.00

43.00