Overview of Malay Basin petroleum system

2. (adapted from OGJ, 2018)

3. Semicratonic Indosinia and Sundaland of Southeast Asia. The Malay Basin is
underlain by a segment of the Three Pagodas fault zone (H. D. Tjia, 2010)
a) Pre-Miocene or possibly earlier than Oligocene
- which represent extensional phase of basin development
b) Early to Middle Miocene - period of thermal subsidence that
accompanied by compression which resulted in local inversion
c) Late Miocene to Quaternary of minor subsidence
- which represents a tectonically quiescent period
Extrusion of Malaya and Indochina continental blocks
resulted from collision between the India plate and the Eurasia
plate (Tapponnier et al., 1982)

4. (adapted from Mansor et al., 2014)

5.  subdivided informally based on
seismostratigraphic unit known as "Group" (Group
A to Group M)
The stratigraphic development of Malay Basin is
related to its structural evolution which occurred
in 3 phases:
i. Pre-Miocene
ii. Early to Middle Miocene
iii. Late Miocene to Quaternary

6. Extensional / Synrift phase
(Pre-Miocene)
 Group M-K
 Development during subsidence,
which controlled by faulting
 Sedimentation took placed in isolated
half graben depo-centres and
deposited thick synrift successions of
alternating sand-dominated and shale-
dominated
Lacustrine shales are accumulated in
many of the isolated graben
(modified from Madon, 1999)

7. Thermal subsidence phase
(Early to Middle Miocene)
 A cyclical succession of offshore
marine, tidal-estuarine, coastal plain and
fluvial sediments was deposited
 Group J & I
-progradational to aggradational fluvial to
tidally-dominated estuarine sands
 Group H & F
-dominant with marine to deltaic sediments
with fluvial or estuarine channel
 Group E & D
- deposited by the progradational
stacking of dominantly fluvial or estuarine
channels
(modified from Madon, 1999)

8. Subsidence phase
(Late Miocene to Quaternary)
 gentle subsidence without
significant tectonic activity happen
 open marine environment
 Group A & B
 consist of marine clay and silts
which were deposited during
marine transgression in near shore
to shallow marine
(modified from Madon, 1999)

10. a) Lacustrine
b) Fluviodeltaic
-Shale rich in algal component
- Oligocene to Early Miocene
- South: Group J, K, L and M within
oil window
- North towards basin centre: Group
K the most oil-prone lacustrine shale
- coastal plain shales and coaly
/carbonaceous shale
- Lower to Mid-Miocene in Group I&E
- Group E: immature HC
- Group I: Closed petroleum system,
the oil window extends as ring around
entire basin Summary of source rock characteristics (hydrogen index, HI vs total organic
carbon, TOC) and potential source rock with different group (adapted from
Madon, 1999)

11.  Sandstone from Group D to K
 Group K, L, M mainly fluvial channels in non-marine lacustrine effects
 Group I & younger is fluvial deltaic to estuarine channel complex
 Group J is the best quality reservoir
contains 40% of total reserves in basin
 middle group J is estuarine & high energy subtidal deposits
 deposition occured during sea level fall
the grains are coarsening upward

12.  Traps associated
with normal
faults (1)
 Compressional
anticlines (2)
 NE ramp margin
(3&4)
Schematic cross sections of Malay Basin showing different trapping styles
(adapted from Madon, 1999)

13.  In Malay Basin: South is oil-prone (middle late Miocene) and North is gas-
prone
 Hydrocarbons occur in Group L to D. Group E, I, J and K are the most prolific
 Stratigraphic distribution of oil and gas primarily controlled by basin
morphology
 Main factors controlling oil and gas distribution including source rock quality
and maturity, and relative timing of generation and structuration.

14. • Bishop, M., (2002). Petroleum systems of the Malay Basin province, Malaysia. USGS
• Madon, M. (1999). In book: Petroleum Geology and Resources of Malaysia. Chapter: 8
• Mansor, M. Y., Rahman, A. H., Menier, D., & Pubellier, M. (2014). Structural evolution of Malay
Basin, its link to Sunda Block tectonics. Marine and Petroleum Geology, 58, 736-748
• Tapponnier, P., Peltzer, G., Ledain, A.Y. & Andarmijo, R. (1982). Propagating extrusion tectonics
in Asia: new insights from simple experiments with plasticine. Geology 10, 611-616
• Tjia, H. D. (2010). Growing evidence of acitve deformation in the Malay basin region. Bulletin of
the Geological Society of Malaysia 56 (2010) 35-40