Awang H. Satyana

SKK Migas, Executive Advisor

Outer Banda Arc, East Indonesia:Proven Petroleum & Prospectivity

SEMINAR BIDANG MIGAS, BADAN GEOLOGIJakarta, 25-26 Oktober 2017

Discussion

1. Regional Overview

2. Seram

3. Timor

4. Tanimbar-Kei

5. Summary

Discussion

1. Regional Overview

2. Seram

3. Timor

4. Tanimbar-Kei

5. Summary

Present Tectonic Setting of Indonesia

Collision of Australia Continent with Banda Arc

Eastern Indonesia: Tectonic Provinces and Structural Trends

OIL/GAS Pertamina & Corelab (1999)

Timor – Tanimbar – Seram

• Timor-Tanimbar-Seram are islands of the Banda Arc. They encircle the

Banda Sea. They represent the Pliocene collision zone between the margin

of the Australian continent and the Banda Arc. The Australian continental

margin now underlies the outer slope of Timor-Tanimbar-Seram.

• The geology of Timor-Tanimbar-Seram shows the structural characteristics

of a foreland fold belt, consisting of thrust-imbricated sequences of the

Australian outer continental margin, and post-collision molassic deposits.

• In this area, Seram Island is productive with Bula and Oseil oil fields, and

Timor Island has numerous oil and gas seeps. Proven play types are

collided Mesozoic Australian sequences and post-collision Pleistocene

molassic deposits. In several areas Seram are still prospective, Timor-

Tanimbar-Kei needs more G&G works to know better their prospectivities

(onshore-offshore). Productive play types in Seram Island may occur in

Timor-Tanimbar-Kei considering their geologic similarity.

Pertamina & Corelab (1999)

Pertamina & Corelab (1999)

Stratigraphy of Banda Outer Arc

(Charlton, 2004)

Howes and Tisnawijaya (1995)

Areas in Eastern Indonesia proven and prospective for exploration

Abadi (2000)

Lofin (2015)

Howes and Tisnawijaya (1995)

Howes and Tisnawijaya (1995)

Discussion

1. Regional Overview

2. Seram

3. Timor

4. Tanimbar-Kei

5. Summary

O’Sullivan et al (1985)

SERAM

30 km

Deformation of the Seram Collision Zone

Pairault et al. (2003)

O’Sullivan et al (1985)

Kemp (1995)

Duplex – imbricated structures of Seram collision

Australian Basement-Involved Inversion in East Seram

F

Tertiary Bula BasinSeram Series

Pre-TertiaryAustralian Series

OSEIL FIELD

BULA FIELD

Seram pre-collision, syn-collision, post-collision

Pre-Terriary(Australian Continent Series)

Tertiary Bula Basin(Seram series)

Thrust Faults

Unconformity

NESW

Nilandaroe et al. (2002)

Jurassic Manusela Carbonates, Seram Island

transversal normal faults around the well

Kemp and Mogg (1992)

Oil Generation & Migration in Eastern Seram

Proven Petroleum and Prospectivity of Seram Island

Seram Oils

API: 15-23°sulfur content: 0.94-2.95 %wtpristane/phytane: 0.48-0.77oleanane index: 0C29 norhopane > C30 hopane

source

Discussion

1. Regional Overview

2. Seram

3. Timor

4. Tanimbar-Kei

5. Summary

Australian –Timor Arc collision

Timor Trough is not a subduction trench but a foredeep within the Australian margin

Hall and Wilson (2000)

Charlton (2002)Surface geologic map of Timor Island

Timor: Distribution of Oil Types and Source RocksTimor Leste Govt. (2006)

Timor: Oils to Sources Correlation using Carbon Isotopesmod. after Timor Leste Govt. (2006)

source

oil

Correlation using Carbon Isotopes

DIAGRAM KOMPOSISI STERANA

Oil Seeps of Belu Regency, West Timor: Pre-Tertiary Carbonate Source

Lemigas (2012)

Livsey et al. (1992)Facies map – Triassic/Lower Jurassic

Stratigraphy of Timor, showing the main source and reservoir sequences

Charlton (2002)

source

Untested sub-Kolbano large

inverted structure

Charlton (2002)

Charlton (2002)

Sani et al. (1995)

Banli-1 dipmeter

Discussion

1. Regional Overview

2. Seram

3. Timor

4. Tanimbar-Kei

5. Summary

Tectonic setting of Tanimbar-Kei area

Pertamina BPPKA (1996)

Geologic cross section across Tanimbar-Kei areaPertamina BPPKA (1996)

Stratigraphy of Tanimbar area

Pertamina BPPKA (1996)

Play concepts of Tanimbar areaPertamina BPPKA (1996)

Semai Area

• Lengkuas -1 (Murphy Semai II, 2010): Jurassic & Paleocene sandstones, Miocene carbonate objectives: dry well, thin & tight Jurassic sandstone, no Paleocene sandstone, no show at Miocene carbonate.

• Andalan -1 (Hess Semai V, 2011): Jurassic & Triassic sandstones objective: dry well, 30-60 ft Jurassic sandstone, Triassic, tight, water-bearing.

• Andalan -2 (Hess Semai V, 2011): Miocene carbonate, dry well, encountered reworked carbonates, poor reservoir quality, no show.

• Serai -1 (Murphy Semai II, 2014): Jurassic sandstone objective: dry well, 17.8 m Jurassic sandstone, 9.6 % porosity, water-bearing.

• Bawang Putih -1 (Murphy Semai II, 2014): Jurassic sandstone objective: dry well, very tight sandstone to metasandstone.

LENGKUAS-1

SERAI-1

ANDALAN-1

ANDALAN-2

BAWANG PUTIH-1

Wells of Semai Area

Geologic Risks

• Deeply buried reservoir rocks-poor quality reservoirs, later uplifted.

• Late-formed structures, post-dating main charging period.

Prospecting for the Future

• Look for Early Jurassic sandstones which has not undergone later subsidence and thick burial covering.

• Look for early-formed structures (in Late Miocene or Mio-Pliocene time), pre-dating main charging period.

• Ways to do: do many stratigraphic and structural reconstructions, seismic attribute (inversion) analysis before drilling later well.

What should we do for later exploration of Semai

Discussion

1. Regional Overview

2. Seram

3. Timor

4. Tanimbar-Kei

5. Summary

Pertamina and Corelab (1998)

Oseil

A B C

D

E

2

1

34

51. TANGGUH FIELD COMPLEX2. ABADI3. ASAP-MERAH-KIDO4. LOFIN5. DONGGI-SENORO-

SUKAMAJU-CENDANAPURA

PLAY TYPES OF EASTERN INDONESIA

picture is mod. after Nayoan et al. (1991)

Satyana (2016)

SIGNIFICANT DISCOVERY

Thank you for your attention.

e-mail: aharun@skkmigas.go.id aharunsatyana@gmail.com

free download of Awang’s papers (80 papers)https://unpad.academia.edu/AwangSatyana/Papers