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Outer Banda Arc, East Indonesia: Proven Petroleum & Prospectivity

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Outer Banda Arc, East Indonesia: Proven Petroleum & Prospectivity SEMINAR BIDANG MIGAS, BADAN GEOLOGI Jakarta, 25-26 Oktober 2017 Outer Banda Arc, East Indonesia: Proven Petroleum & Prospectivity Awang H. Satyana SKK Migas, Executive Advisor 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) Areas in Eastern Indonesia proven and prospective for exploration Lofin (2015) Abadi (2000) Howes and Tisnawijaya (1995) Howes and Tisnawijaya (1995) Howes and Tisnawijaya (1995) Discussion 1. Regional Overview 2. Seram 3. Timor 4. Tanimbar-Kei 5. Summary SERAM O’Sullivan et al (1985) Pairault et al. (2003) 30 km Deformation of the Seram Collision Zone O’Sullivan et al (1985) Kemp (1995) Duplex – imbricated structures of Seram collision Seram pre-collision, syn-collision, post-collision Australian Basement-Involved Inversion in East Seram F OSEIL FIELD BULA FIELD Pre-Tertiary Australian Series Tertiary Bula Basin Seram Series SW NE Tertiary Bula Basin Unconformity (Seram series) Pre-Terriary (Australian Continent Series) Thrust Faults Jurassic Manusela Carbonates, Seram Island transversal normal faults around the well Kemp and Mogg (1992) Nilandaroe et al. (2002) Oil Generation & Migration in Eastern Seram Proven Petroleum and Prospectivity of Seram Island Seram Oils API: 15-23° sulfur content: 0.94-2.95 %wt pristane/phytane: 0.48-0.77 source oleanane index: 0 C29 norhopane > C30 hopane Discussion 1. Regional Overview 2. Seram 3. Timor 4. Tanimbar-Kei 5. Summary Australian –Timor Arc collision Hall and Wilson (2000) Timor Trough is not a subduction trench but a foredeep within the Australian margin Charlton (2002) Surface geologic map of Timor Island Timor Leste Govt. (2006) Timor: Distribution of Oil Types and Source Rocks Correlation using Carbon Isotopes source oil mod. after Timor Leste Govt. (2006) Timor: Oils to Sources Correlation using Carbon Isotopes Oil Seeps of Belu Regency, West Timor: Pre-Tertiary Carbonate Source DIAGRAM KOMPOSISI STERANA Lemigas (2012) Facies map – Triassic/Lower Jurassic Livsey et al. (1992) Stratigraphy of Timor, showing the main source and reservoir sequences source Charlton (2002) Untested sub- Kolbano large inverted Sani et al. (1995) structure Charlton (2002) Banli-1 dipmeter Charlton (2002) 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 area Pertamina BPPKA (1996) Stratigraphy of Tanimbar area Pertamina BPPKA (1996) Play concepts of Tanimbar area Pertamina BPPKA (1996) Semai Area BAWANG PUTIH-1 SERAI-1 LENGKUAS-1 Wells of Semai Area ANDALAN-2 ANDALAN-1 • 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. What should we do for later exploration of Semai 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. Discussion 1. Regional Overview 2. Seram 3. Timor 4. Tanimbar-Kei 5. Summary Oseil Pertamina and Corelab (1998) SIGNIFICANT DISCOVERY 1. TANGGUH FIELD COMPLEX 5 2. ABADI 1 3. ASAP-MERAH-KIDO 4 4. LOFIN 3 5. DONGGI-SENORO- SUKAMAJU-CENDANAPURA D 2 E A B C picture is mod. after Nayoan et al. (1991) Satyana (2016) PLAY TYPES OF EASTERN INDONESIA Thank you for your attention. free download of Awang’s papers (80 papers) https://unpad.academia.edu/AwangSatyana/Papers e-mail: [email protected] [email protected].
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