Petroleum systems in Southeast Asian Tertiary basins

Abstract

Productive Tertiary basins in Southeast Asia have essentially similar geodynamic developments, and share many hydrocarbon habitats and active petroleum systems. In order to facilitate understanding of the essential elements that contribute to the success of petroleum systems I have classified them into a number of groups or 'associations' according to their sedimentary facies. This facilitates use of them as valuable analogues. Five such facies associations, containing characteristic and distinct petroleum parameters have been recognised: (i) lacustrine (ii) paralic (iii) open marine shelf (iv) deeper marine and (v) pre-Tertiary. They belong to particular cycles or stages in basin development that provide the context within which the depositional environments and palaeogeography evolve. Lacustrine facies typify the early stages of synrift development in basins closer or more proximal to the Sundaland province in northern and western SE Asia. Open marine facies, on the other hand, typify the early postrift period and basins in palaeogeographically more distal areas, such as eastern Indonesia and The Philippines. Paralic and bathyal facies characterise the later stages of the synrift and postrift cycles and are widespread throughout the proximal and intermediate parts of the area. Pre-Tertiary source facies, which provide charge in parts of eastern Indonesia and Thailand, are mainly terrestrial in nature. These differences have important implications for petroleum occurrence, which can be summarised accordingly: • More proximal basins are dominated by lacustrine to paralic facies in the synrift cycle and have a mainly nonmarine sedimentary fill. Petroleum systems with oil charge are dominant. • More distal basins are dominated by rapid postrift subsidence. In the open marine facies carbonate reservoirs are well-developed, while petroleum systems are mainly gas-prone. • Around Borneo thick late postrift passive margin delta sequences with oil-and gas-prone coaly source rocks and clastic reservoirs are developed in delta-top environments. Transported terrigenous organic material is commonly found in related deep marine environments and contributes to a marine source facies. Both give rise to prolific petroleum systems. • Many basins in the Sunda Shelf area lie in an intermediate situation, where a non-marine synrift is followed by a marine postrift cycle. Such basins benefit from lacustrine and paralic source rock and reservoir sequences in both the syn-and the postrift, and are often characterised by multiple petroleum systems. Evaluation of petroleum potential in Southeast Asian Tertiary basins requires a special approach: in most parts of the World, such as the Middle East and Northwest Europe, source rocks are of marine origin, are relatively consistent in type and quality and are located in well-defined formations of regional extent. In SE Asia the terrestrial and lacustrine source rocks are more difficult to locate, are variable in quality and are often distributed in thin beds throughout thick sequences. These...

Major structural unconformities across Malaysia: geodynamics and basin development of Lawin, Perak

“…A deep-faulted opening, as observed on cross-section (Figure 4). It was further extent regionally in the E-W direction following a N-S compression which could be due to the extrusion of the Southeast Asia after the collision of India and resulted in N-S normal faults and subsidence in the area of the area of a Perak Valley [20] (Figure 3b). Along the N-S dip-slip fault which formed space for accumulation, the low region had deposited the Lawin conglomeratic series.…”

The Integration of Geochemical Characteristics and Stable Isotopes Analyses of δ2H and δ18O in the Paleogene Carbonate Rocks Unit of the M-Field, Ciputat Sub-Basin, North West Java Basin, Indonesia

“…The Ciputat Subbasin was also formed and affected by the North West Java regional tectonic as well as subduction system of Southern Java. There were at least 4 stage of tectonics related to rifting process (Doust and Noble, 2017) which driven the geology and stratigraphy of the North West Java Basin, the early synrift, the late synrift, the early post rift and the late post rift. The Ciputat Sub-Basin presumed to start developed during the pre-rift tectonic event on the North West Java Basin upon the pre-Tertiary basement as described in the previous regional study shown in Figure 2.…”

A Workflow to Define, Map and Name a Carbonatite- or Alkaline Igneous-Associated REE-HFSE Mineral System: A Case Study from SW Germany

“…The Mineral System Definition stage is based upon geological processes. The objectives are to: (a) Define, map, and name any carbonatite or alkaline igneous-associated REE-HFSE mineral system at province scale, (b) determine the spatial and temporal distribution of the system's critical components, (c) genetically link REE-HFSE occurrences to each other and to their provenance, and (d) apply a contextual mineral system approach to evaluate the boundaries and uncertainties within which undiscovered plays and prospects may occur (modified from Reference [52]). It is a province-scale screening technique, so does not calculate any resource volumetric value, i.e., no detailed economic considerations.…”

“…For example, a magmatic mineralization may be used as a locus for proximal fluvial deposits, whilst lateritic deposits may indicate a location of under cover magmatic mineralization. These four facies associations incorporate the lithofacies associations concept and methodology of Reference [52], and maintain alignment with "magmatic-related", "metamorphic-related", and "basin-and surface-related" "mineralizing system families" [25]. They also parallel the four REE "mineral system associations" [42], except that we expand those authors' Regolith "Mineral-system association" [42] to Weathering, to accommodate the possibility of karst-associated mineralization in weathered carbonatite bodies.…”