Seismic Atlas of SE Asian Basins

Gorontalo Basin

Location map of Tomini Bay
and Gorontalo Basin

Seismic section across Gorontalo Basin (Source: Fugro)

Gorontalo Basin is located under the Tomini Bay and is limited by the neck and the north and east arms of Sulawesi Island. The basin opens to the east towards the Molucca Sea. Maximum water depth in the basin goes deeper than 2000 m and sediment thickness is up to about 7 km. The basin still lacks of hydrocarbon exploration activities at the moment, therefore there is no accurate information about the ages of basin-fills.

Regional tectonic reconstruction of Hall (2002) shows that part of the proto-Gorontalo Basin was most likely located in a fore-arc setting since Middle Eocene to Early Miocene, with the arc being the north arm of Sulawesi.

Tectono-stratigraphic Evolution of Western Gorontalo Bay, Indonesia
Parinya Pholbud (PTTEP)
Abstract, MSc in Petroleum Geoscience, Royal Holloway, University of London, Department of Earth Sciences,

Fugro seismic survey in Gorontalo Basin

Gorontalo Bay exists as one of eastern Indonesia’s mystery basins in terms of its tectonic evolution and stratigraphy. Detailed interpretation of newly acquired regional 2D seismic data provides an understanding of the tectono-stratigraphic evolution of the western part of Gorontalo Bay.

The formation of western Gorontalo Bay and adjacent areas is related to thermal subsidence initiated during the Early Miocene, associated with plate tectonic collision in Sulawesi (—23 Ma). This event initiated the development of the fore-arc basin along a NE-SW trending zone of weakness in Oligocene and older basement rocks. The NE-SW trending basin was filled by thick deep marine sediments. Subsidence was interrupted by a later uplifting event along the southeastern margin.

Carbonates became dominant in this basin following the formation of a thick carbonate platform. The shallow marine carbonates were developed widely in the basin before rapid subsidence to the present-day deep water (2 km depth). This rapid subsidence is the result of the Celebes Sea subduction and trench rollback during the Pliocene (—5 Ma) to Recent.

Example of seismic data from the Gorontalo Basin
(source: Fugro / searcherseismic.com)

The results from this study imply that this basin potentially has a petroleum system for future hydrocarbon exploration according to the depositional environments. Hydrocarbon could be sourced from mature deep marine sediments in the basin centre. Mixed grain rocks, fractures and local unconformities within the sedimentary mega sequences potentially form economical stratigraphic plays. These should be the major targets for hydrocarbon exploration in this area.

Supervisor: Robert Ha1l, Marta Pérez-Gussinyé & Chris Elders
Data provided by: Searcher Seismic, Fugro Multi Client Services PTY Ltd & TGS-Nopec

South Java Basins

South Java Basins
The western Indonesian fore-arc basins extend more than 1800 km from northwest of Aceh to southwest Java. The width of the basins varies from less than 70 km south of the Sunda Strait to about 120 km in the west off northern Sumatra. The basins form a strongly subsiding belt between the elevated Sumatra Paleozoic–Mesozoic arc massif cropping out along Sumatra and Java, and the rising outer arc high.

(Contributor: Dieter Franke, BGR)

Seismic Sections:

Figure 1. Location map of line ABB-SO-137-31, south of Banten, West Java.

Figure 2. NW-SE oriented uninterpreted section of line ABB-SO-137-31. Data courtesy: BGR

Figure 3. Interpreted section of line ABB-SO-137-31. Data courtesy: BGR

Figure 4. Location of line ABB-SO-137-36

Figure 5. SW-NE orientation seismic line ABB-SO-137-36. Data courtesy: BGR

Figure 6. Interpreted seismic line ABB-SO-137-36. Data courtesy: BGR

Data Provider

The main data provider for this online atlas are:

The committee are thankful for their contributions

Sandakan Basin

Sandakan Basin is located in the northern part of Borneo Island. Similar to other circum-Borneo basins, the Sandakan Basin is dominated by shallow to deep marine clastics sequences.

Fig. 1. NW-SE Seismic Section of part of Sandakan Basin (Petronas, 2000).

Foreset features of Sehabat Formation, indicating sediment transport from NW to SE. Source: Petronas 2000 in Tate, 2001.

Fig. 2. Manalunan-1 geoseismic interpretation after Wong, 1993.

A scetch of a seismic section across Manalunan-1 well which penetrated the Sehabat formation (Modified after Wong, 1993)

Fig. 3. NW-SE orientation seismic section (Petronas 2000)

NW - SE orientation seismic section

shows Pad Basin which is bounded by 2 flower structure system (Source: Petronas 2000 in Tate, 2001)

Fig. 4. Seismic section and well distribution of Futalan et al. (2012) study.

Futalan et al.(2012) published 2 seismic lines in the Philippines territory of Sandakan Basin (Fig. 4).

Fig. 5. Seismic section of Futalan et al. (2012)

Fig. 6. Seismic section across Hippo-1 well (Futalan et al., 2012)

Seismic interpretation along a seismic section by Futalan et al., 2012.

A zoom in and detail seismic interpretation across Hippo-1 well is shown in Fig. 6.

References:
Futalan, K., Mitchell, A., Amos, K., & Backe, G., Seismic Facies Analysis and Structural Interpretation of the Sandakan Sub-basin, Sulu Sea, Philippines, Search and Discovery Article #30254 (2012) Posted October 29, 2012

Natuna Sea and Sarawak Basin

The Natuna Sea area is the southern extension of the South China Sea, mainly in the Indonesian territory. This area is divided by two parts by Natuna Arch, namely West Natuna Basin which extend to Malay Basin in West Malaysia and East Natuna Basin which extend of Sarawak Basin in East Malaysia

The West Natuna Basin was formed as an intra-continental rift basin within the Sunda Platform, the southern margin or Eurasian Plate. The basin has undergone Eocene-Oligocene extension, followed by Miocene to present day contraction and inversion.

In Late Cretaceous-Early Eocene reconstruction, East Natuna Basin was part of a large fore-arc basin extending from offshore Veitnam, across Natuna Sea to Sarawak. The SW-NE trending structures in East Natuna Basin are controlled by extensional faults and half grabens similar to the ones found in West Natuna Basin, but the rift magnitude is generally less than the ones in the West Natuna Basin.

West Natuna Seismic Sections
Seismic reflection section over the Anambas graben. Tectonic inversion over the graben occurred during the Miocene. Brown marker is the top Oligocene, Gabu formaion wheras the blue marker represents the Pliocene unconformtiy after inversion. The bright spots near basement may represent lacustrine source rocks with high TOC. Source: Fenstein, 2000.

Play concepts for West Natuna basin (Netherwood R., 2000, after Fainstein and Meyer, 1988)

East Natuna Seismic Sections

Seismic reflection section of East Natuna. No inversion occurs in this area. Blu marker represents top of carbona te reservoirs. Bursa is an oil field and Alpha-D is teh giant Natuna gas field (source: Fainstein, 2000).

Play concepts for East Natuna basin (source: Netherwood R., 2000, after Fainstein and Meyer, 1998)

ION Geophysics acquired deep seismic in Natuna area. The sections go as deep as 40 km. Below are a map and a sample section from their brochure

References:
Netherwood R., 2000, The Petroleum Geology of Indonesia, in: Blunden, T. (ed.), Indonesia 2000, Reservoir Optimization Conference, Schlumberger

Makassar Strait Basins

Tectonic provinces in the Makassar Strait Region (Darman, 2014)

Makassar Strait is located between Borneo and Sulawesi Island. In general the region is separated into two parts by NW-SE Adang - Paternoster Lateral Fault. The northern part compose of Kutei Basin in the west, North Makassar Basin in the centre and two basins in the east called Lariang and Karama Basins. Palu-Koro Fault set the northern boundary of the northern part. Paternoster Platform and the South Makassar Basin is located in the southern part of this region.

Fig. 2. PGS-1 South-North Seismic section across across Makassar Strait (Source: PGS)

PGS has processed and published a NS seismic line which cross different tectonic unit in the Makassar Strait. PGS-1 line goes across Muara Sub-basin of Tarakan Basin in the north, Mangkalihat Platform, North Makassar Basin, South Makassar Basin, Paternoster Platform and Lombok Basin.

Fig. 3. Location map fo PGS-1 seismic line

1. Palu Koro Fault

Fig. 4. TGS seismic line which shows the Mangkalihat Platform

and the Palu Koro Fault system (right; Baillie, 2005)

The NW-SE oriented Palu Koro Fault system developed in the north of Makassar Strait. This fault is still active and generated a number of significant earth quake in Sulawesi onshore. The seismic section offshore shows a rough seabottom. Figure 4 shows a seismic section across the Mangkalihat Platform on the left and rough sea-bottom topography on the right, which is caused by the Palu-Koro fault system. Figure 5 provide the zoom-in image of Figure 4 to show the detail of the Palu-Koro fault system.

Fig. 5. TGS Seismic line, showing the detail of the Palu Koro

Fault in Fig. 4 (Baillie, 2005)

2. Offshore Kutei Basin

Fig. 6. TGS MDD99 Line 19, showing the eastern margin

of offshore Kutei Basin.

The majority of Kutei Basin covers the eastern part of Borneo onshore. The drainage basin supplied sediments to the paleo-Mahakam Delta which develop further as deepwater system in the Makassar Strait. TGS MDD99 Line 19 (Fig. 6) shows the margin between the offshore Kutei Basin and the Northern Makassar Strait. The seismic section shows minimum deformation in the Northern Makassar Strait (right of Fig. 6) and potential toe-thrust system developed in the outer margin of the offshore Kutei Basin (left of Fig. 6).

PGS 3D seismic reprocessing in the southern part of offshore Kutei Basin (Fig. 7) provide some detail images of the deltaic - deepwater system.

Fig. 7. Location map of the 3D seismic reprocessed by PGS.

Fig. 8. Dip line of PGS 3D seismic

Fig. 9. Strike line of PGS 3D seismic

3. Lariang Basin

Fig. 10. Seismic expression of North Makassar Strait (left) and

Majene thrust belt (right). After Baillie, 2005.

Structural Styles of the West Sulawesi Deep-Water Fold and Thrust Belt, Makassar Straits, Indonesia

by Jose de Vera & Ken McClay Fault Dynamics Research Group, Royal Holloway, University of London, Egham, United Kingdom

Southeastern part of Makassar Basin, Deepwater fold

belts. Source: TGS

The offshore margin of West Sulawesi (eastern Makassar Straits) is characterized by an active, Late Miocene/Early Pliocene to present day, NE-SW-trending and NW-verging deepwater fold and thrust belt. The fold and thrust is approximately 250 km long and as much as 75 km wide and consists of an Oligocene to present day succession that was deposited on subsiding, thinned, rifted continental crust and is now deformed by SW-to NE-verging thrust fault-related folds deformed on multiple detachment layers. Based on the across strike variations in structural style and bathymetry changes, the West Sulawesi fold and thrust belt can be divided into five across-strike main structural domains. From northwest to southeast these are: the abyssal plain, the deformation front, the folded domain, the thrust domain and the inversion domain. The abyssal plain is solely deformed by Pliocene to Pleistocene, low-displacement, planar extensional faults, which are interpreted to be the result of flexural subsidence ahead of the advancing thrust front. The structural styles of the deformation front are strongly controlled by inversion of the Pliocene to Pleistocene extensional faults. Inversion of pre-existing faults controls fault localization and fold vergence, giving rise to complex wedge and triangle zone geometries.

Southeastern part of Makassar Basin, Deepwater fold

belts. Source: TGS

The structural styles of the folded and thrust domains are characterized by complex NW- to SE-trending detachment and fault-propagation folds, with multiple detachment levels developed in Oligocene and Miocene mudstones. The inversion domain is the innermost and oldest element of the thrust belt and consists of large anticlines that resulted from reactivation of Paleocene rift structures. The results presented in this work are based on the structural analysis of 3480 km of regional 2D seismic lines.
The structural patterns described here have implications for understanding fault-fold geometries and growth in other deepwater fold and thrust belts.

Reference:
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009

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South Sumatra Basin

The South Sumatra Basin is most southern back arc basin of Sumatra Island. It is bounded to the west by an active volcanic arc along the Sumatra Fault System.The basin has long petroleum history. Significant number of oil and gas fields were discovered in this basin. Example of several seismic section across several fields in this basin are displayed here:
1) Suban Field
2) Kaji Semoga

Depth to basement map of South Sumatra Basin shows the isochrone contours in Two-Way-Time. The map shows the position of oil and gas fields relative to the depocenter (Darman & Yuliong, 2020)
1. Suban Field
The Suban Field is located on top of a basement high as shown the following regional section prepared by Hennings et al, 2012 (in Marino Baroek, 2015). The stratigraphic units described in this section are:
6. Upper Nuicebe-Pliocene sandstone, shale, coal, volcanic - Kasai Formation
5. Middle-Upper Miocene sandstone and shale
4. Lower-Middle Miocene organic shale and rare sandstone - Telisa Formation
3. Lower Miocene platform and reefal (3a) carbonate - Batu Raja Formation
2. Paleogene/Neogene granite wash and clastic sequences - Lemat and Talangakar Formations
1. Sub-Cenozoic crystalline and metamorphic basement

Hennings et al, 2012 also prepared a field scale seismic section, showing several segments of the field, named Southwest, Centre and Northeast Domain, shown on the following figure.

2. Kaji Semoga Field

Hutapea et al., (2000) published some information about Kaji-Semoga field in South Sumatra Basin.

Two seismic sections of Kaji and Semoga Field are displayed here:

Section A went from West to East, crossing both Kaji and Semoga Field.

The lowest horizon in red is the top of the granitic basement. Both Kaji and Semoga Field are consist of carbonate reefs of Baturaja Formation, which built on top of basement high.

Section B is a North-South section across Kaji Field. Generally the basement is getting deeper southward in this part of the basin.

Below are some seismic sections after Team Kepmen / Minister Decree Team, who did the South Sumatra Basin (SSB) remaining potential evaluation in 2023. The report is published by SKKMIGAS.

Seismic-well tie at East Ketaling-1 well location. This section shows the thickening of Talang Akar - Benakat Formation. The top of basement picking is as its best for the given seismic data.