West Palawan Basins

The West Palawan Basin is located in the west of Palawan Island, southwest of the Philippines. A lateral fault called  Ulugan Bay Fault separates the basin to NW and SW Palawan Basin. The NW Palawan basin is known for its Nido Limestone formation which is the reservoir of the Malampaya Field. The age of Nido Limestone formation is range from Late Oligocene to Early Miocene. The SW Palawan Basin is dominated by a younger limestone formation called Likas Formation which was deposited in the Upper Miocene until Early Pliocene.

• Northwest Palawan Basin

A seismic section displayed in Pictin Petroleum website is an example of a 3D seismic in Block or Service Contract (SC) 6A, Octon Block, Offshore NW Palawan, Philippines. This seismic line is NW-SE in orientation across East Berselisa and West Malajon structure. The Nido Limestone formation is displayed here as a blue horizon.

There are more seismic available which cover the Malampaya Field. This seismic lines show the character of the carbonat. It is possible to observe its carbonate framework and facies development within the limestone based on seismic.

• SW Palawan

Location of seismic lines in Ma Corazon Victor Sta's thesis, 2006

The Southwest Palawan basin has more Neogene Limestone deposit, which is called Likas Formation. A thesis by Ma. Corazon Victor Sta. Ana include a number of good quality seismic lines which show interesting carbonate features and structures.

The seismic displayed covers the southern part of the SW Palawan Basin.

Seismic profile along the southern portion of strike line DPS93-4b. (a) Unintrepreted
(b) Interpreted. Note generally steeper south-facing side of platform is steeper and north-facing
margin has gentler slopes, which reflects prevailing wind direction during platform growth.
Faults above the carbonate strata could be due to compaction. Vertical scale is in milliseconds
two way time.

Source: Ma. Corazon Victor Sta. Ana (2006)

Seismic profile along strike line PA-105. (a) Uninterpreted. (b) Interpreted.
The profile shows a broad, flat-top platform with late growth stage pinnacle reefs at the margins.
Note steep slope and high platform-to-basin relief at the northern edge of the platform.
Clinoforms in the northwestern part of the line shows syntectonic platform growth. Vertical scale
is in milliseconds two way time. Seismic profile along dip line

Source: Ma. Corazon Victor Sta. Ana (2006)

Seismic profile along strike line PA-107 showing the backstepping carbonate
platform. Platform top of Pink sequence shows higher platform-to-basin relief. Vertical scales is
in milliseconds two way time.


Source: Ma. Corazon Victor Sta. Ana (2006)

Seismic profile along strike line PA-113 showing basinal and platform margin
facies. (a) Uninterpreted (b) Interpreted. Note onlap of basinal facies on flanks of the isolated
platform. Vertical scale is in milliseconds two way time.

Source: Ma. Corazon Victor Sta. Ana (2006)

Seismic profile along dip line PA-134. (a) Uninterpreted (b) Interpreted. This profile
shows the tilted platform on the eastern part of the study area. Notice the chaotic seismic facies
at the zone of uplift. This is probably due to fracturing caused by the uplift or karstification.
Vertical scale is in milliseconds two way time.

Source: Ma. Corazon Victor Sta. Ana (2006)

PA-136 showing varied platform morphology. (a) Unintrepreted (b) Interpreted. Faults significantly affected the platform architecture. Vertical scale is in milliseconds two way time.

Source: Ma. Corazon Victor Sta. Ana (2006)

Seismic profile along dip line PA-138. Faulting significantly modified the platform morpholody. Note the differences in platform morphology. Vertical scale is in milliseconds two way time

Source: Ma. Corazon Victor Sta. Ana (2006)

Seismic profile along strike line SP97-01. (a) Uninterpreted, (b) Interpreted. Faulting controlled seismic facies location (arrows) which indicate a strong tectonic effect during the platform growth. Vertical scale is in milliseconds two way time.

Luconia / Sarawak Basin

Luconia Basin is located offshore Sarawak, Malaysia


NW-SE seismic profile across Luconia Platform and Mid. Miocene Balingian Delta and rift in deewater. Rectangle shows location of the following seismic line (Source: Thies et al., 2006)

Detail of part of seismic line above, showing listric fault bounding half graben, with rift and post-rift deposit (Source: Thies et al., 2006)

Seismic line showing rift cycles in half graben.

Seismic line CD89-110 (Mulu-1 Tie Line) showing log of Mulu-1 and rift cycles 1 and 2 on horst.

Reference: Structural and Stratigraphic Development of Extensional Basins: A Case Study Offshore Deepwater Sarawak and Northwest Sabah, Malaysia, By: Kenneth Thies, Mansor Ahmad, Hamdan Mohamad, Richard Bischke, Jeffrey Boyer, and Daniel
Tearpock, Search and Discovery Article #10103 (2006)

Phu Khanh Basin

Phu Khanh Basin, Vietnam

Phu Khanh Basin is located in the offshore east Vietnam. The bathymetry in this area is relatively steep as it change from several tens of meters to more than 1000 m in less than 100 km.

Key seismic sections are displayed here.
A. Seismic section showing the northern margin of Phu Khanh Basin, towards Song Hong Basin. These two basins are separated by basement high. (source AAPG)

B. Seismic section showing the southern margin of Phu Khanh Basin. The section crossed the basement high which separate Phu Khanh Basin and Cuu Long Basin. (source AAPG)

C. W-E Seismic section in the north of Phu Khanh Basin from Vietnam shallow water to deeper offshore showing relatively steep slope.

D. W-E Seismic section in the north of Phu Khanh Basin

References:
Bojesen-Koefoed, J. A., Nielsen, L. H., Nytoft, H. P., Petersen, H. I., Dau, N. T.,  Hien, L. V.,  Duc, N. A., Quy, N., H., 2005, Geochemnical characteristics of oil seepages from Dam Thi Nai, Central Vietnam: Implications for hydrocarbon exploration in the offshore Phu Khanh Basin, Journal of Petroleum Geology, Vol 28 (1), January 2005, pp 3-18

A. Song Hong - Phu Khanh Seismic Section (source: AAPG)
Nortern margin of Phu Khanh Basin

B. Cuu Long - Phu Khanh Seismic Section (source: AAPG)

Southern margin of Phu Khanh Basin

C. W-E Seismic Section in the north of Phu Khanh Basin (Bojesen-Koefoed et al, 2005), showing potential kitchen area and its migration path.

D. W-E Seismic Section in the north of Phu Khanh Basin (Bojesen-Koefoed et al, 2005). Horst-grabben system develop below the Lower Miocene horizon. A major progradational feature developed in the upper Miocene.







Reference:
Bojesen-Koefoed, J.A., Nielsen, L.H., Nytoft, H.P., Petersen, H.I., Dau, N.T., Hien, L.V., Duc, N.A. & Quy, N.H., 2005: Geochemical characteristics of oil seepages from Dam Thi Nai, central Vietnam: implications for exploration in the offshore Phu Khanh Basin. Journal of Petroleum Geology 28, 3–18.