The Sunda-Banda Arc Transition - First results from recent marine geophysical investigations offshore eastern Indonesia (Part 2)

Sub-Bottom Profiling (SBP) records and results of geochemical analysis of 12 surficial sediment cores from various water depths collected from the offshore Waropen Basin-Papua are presented. Presence of gas is clearly observed on sub-bottom profiler records. Shallow gas was identified through acoustic response due to gas accumulation and gas escape on sub-bottom profiles. Acoustic evidences of gas accumulations within near surface geology consist of high amplitude reflections and associated acoustic blanking, gas plumes and morphological features like pockmarks. Total organic carbon analysis of 12 surface sediment cores varies between 0.5% to 1.3% which indicate that the sediments have an abundance of organic matters. Gas chromatographic analysis of hydrocarbon composition detected only methane, a biogenic origin of shallow gas. Acoustic and geochemical evidence in the Waropen Basin indicates extensive shallow gas accumulations in the Late Quaternary sediments, some trapped within these deposits and some escape from seabed into the water column which then created a high distribution of pockmarks.

Seabed

Petroleum seep

10.7186/bgsm71202110

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OIL AND GAS IN MARINE MESOZOIC OF CHINA SEA AREAS

Marine Geology Letters (2003)

Cai Qian-zhong

The already proved oil and gas in offshore China is mostly found in the continental Tertiary. With the going on of the exploration work especially geophysical prospecting, breakthroughs have been made in the understanding of the possible marine Mesozoic through seismic surveys in the deep water areas in the south of the East China Sea and in the north of the South China Sea (including Chaoshan depression and Taixinan basin). Together with the regional geologic background, the survey results indicate that the marine Mesozoic sediments mainly came from the invasion of the Tethys from west to east. Searching for marine petroleum will become an important object in the future explorations.

Prospecting

China sea

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A Seismic Gap Study in the western offshore of Sumatra, Indonesia

EGU General Assembly Conference Abstracts (2012)

Haekal Azief Haridhi Syamsul Rizal Muhammad Arif Fadhly Ridha C. S. Lee

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PROCEEDINGS, INDONESIAN PETROLEUM ASSOCIATION Thirty-Third Annual Convention & Exhibition, May 2009 HYDROCARBON PROSPECTIVITY OF THE SAVU SEA BASIN

Steve Toothill David Lamb

The Savu Sea Basin is a highly underexplored basin situated between the islands of Flores to the north, Sumba to the west, Timor to the east and the Australian continental shelf to the south. It lies within the southern limb of the Banda Arc, which is the collision zone between the northern margin of the Australian Shelf to the south and the oceanic island arc system which borders the Eurasian plate to the north. Two seismic surveys, acquired in 2002 and 2007 now reveal details of the basin and the surrounding tectonic regimes revealing potential for successful hydrocarbon exploration. The basin covers an area in excess of 50,000sq.km. and in its deepest parts has up to 4.8km of sediment. The surrounding islands have been the subject of detailed geological surveys, in some cases dating back to the late 19th century. However, no wells have been drilled in the basin itself and correlation of seismic horizons is dependent on regional considerations and extrapolation of onshore geology to the offshore. The origin of the basin is highly complex, being situated within an area affected by four to five phases of rifting and interspersed phases of uplift and erosion and overprinted in recent geological time by collision tectonics. It is likely that the oldest rocks in the basin are at least Late Triassic age similar to those on the island of Seram, situated on the northern limb of the arc. The Australian shelf to the south is an established petroleum province as is the Island of Seram. Oil seeps are prevalent on the island of Timor and are scattered across the offshore region as well. The seismic data recently acquired across the basin shows a significant number of gas chimneys and bright amplitudes which may be associated with hydrocarbon migration and trapping. Further evidence for the existence of a petroleum system in the basin comes from satellite seep data. Numerous seeps are evident across the basin and

Prospectivity mapping

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