Southeast Sumatra Research Articles

Investigating the haze transport from 1997 biomass burning in Southeast Asia: its impact upon Singapore

The 1997 Indonesia forest fires was an environmental disaster of exceptional proportions. Such a disaster caused massive transboundary air pollution and indiscriminate destruction of biodiversity in the world. The immediate consequence of the fires was the production of large amounts of haze in the region, causing visibility and health problems within Southeast Asia. Furthermore, fires of these magnitudes are potential contributors to global warming and climate change due to the emission of large amounts of greenhouse gases and other pyrogenic products.The long-range transport of fire-related haze in the region is investigated using trajectories from the CSIRO Division of Atmospheric Research Limited Area Model (DARLAM). Emission scenarios were constructed for hotspot areas in Sumatra and Kalimantan for the months of September and October 1997 to determine the period and fire locations most critical to Singapore. This study also examines some transport issues raised from field observations. Results show that fires in the coastal areas of southeast Sumatra and southwest Kalimantan can be potential contributors to transboundary air pollution in Singapore. Singapore was directly affected by haze from these areas whereas Kuala Lumpur was heavily affected by the haze coming from Sumatra. In most cases, Singapore was more affected by fires from Kalimantan than was Kuala Lumpur. This was mainly a result of the shifting of monsoons. The transition of monsoons resulted in weaker low-level winds and shifted convergence zones near to the southeast of Peninsular Malaysia. In addition to severe drought and massive fire activity in 1997, the timing of the monsoon transition has a strong influence on haze transport in the region.

Short-chain carboxylic acids from the anal glands of the binturong, Arctictis binturong (Viverridae, Mammalia)

The binturong (Arctictis binturong) is a large, arboreal viverrid (subfamily Paradoxurinae) with a coat of long coarse hair and a prehensile tail that inhabits the dense forests of Southeast Asia, Palawan, Sumatra, Java, and Borneo. This species, as with most Carnivora, possesses paired glands that open on both sides of the anus (Story, 1945). These anal glands are used by both sexes to scent-mark (Kleiman, 1974).

The occurrence of the flat-headed cat Prionailurus planiceps in south-east Sumatra

AbstractThree incidental sightings of the flat-headed cat Pnonailurus planiceps, a little-known species, were made in south-east Sumatra. Sightings were on lowland floodplains in two distinct habitats, primary peat swamp forest and secondary lowland forest, the latter suggesting some tolerance to modified habitats. Sightings were along or near waterways. A dead adult male found in Berbak National Park is the first confirmed record for the park. Morphometrics of this individual were consistent with other published measurements for the species. Museum specimens indicate a wide historic distribution in south-east Sumatra. Recent information confirms the species's presence in protected areas of eastern, southern and western Sumatra, although this is mostly limited to presence/absence data, and the conservation status and habitat requirements of the species in south-east Sumatra are unknown. Regional degradation of riparian habitats and the isolation of protected areas warrant concern for the conservation status of the species.

The occurrence of the flat-headed cat Prionailurus planiceps in south-east Sumatra

The occurrence of the flat-headed cat Prionailurus planiceps in south-east Sumatra

ABSTRACT: Re-development of structural-stratigraphic traps in the Wanda Area, Sunda Basin, Southeast Sumatra, Indonesia

ABSTRACT: Re-development of structural-stratigraphic traps in the Wanda Area, Sunda Basin, Southeast Sumatra, Indonesia

ABSTRACT: Creative interdisciplinary team's effort results in economic development of a previously sub-economic field, South Zelda Field, offshore Southeast Sumatra

ABSTRACT: Creative interdisciplinary team's effort results in economic development of a previously sub-economic field, South Zelda Field, offshore Southeast Sumatra

Cenozoic thermotectonic history of the Sunda–Asri basin, southeast Sumatra: new insights from apatite fission track thermochronology

The tectonic and thermal history of Cenozoic rocks from four wells (Asri-1, NE Ria-1, Hariet-1 and Yani-2) in the Sunda–Asri basin has been reconstructed using apatite fission track (AFT) analysis combined with modelling of previously determined vitrinite reflectance (VR) measurements. The wells all penetrate Recent to middle Eocene successions, in which only the Eocene to Oligocene successions have been subjected to temperatures suitable for partial annealing, due to rapid late Miocene to Recent burial. With respect to organic thermal maturities, the zone of minimum annealing coincides with undermature heating and records provenance AFT ages, whilst the zone of partial annealing agrees well with mature heating suitable for generation of hydrocarbons. The integrated AFT and VR data suggest that the Sunda–Asri basin continues subsiding, probably due to extension initiated in the late Eocene, and the successions near the base of the wells were recently exposed to the high present-day temperatures. The recent heating of rocks is consistent with up to 800 m of Plio–Pleistocene burial. Both the AFT and VR results indicate that geothermal gradients remained relatively constant through the Cenozoic.

Exploration history of the offshore Southeast Sumatra PSC, Java Sea, Indonesia

Abstract The Offshore Southeast Sumatra Production Sharing Contract (PSC) is situated in the Java Sea, just north of Indonesia’s capital, Jakarta. It was the first to produce offshore oil in Indonesia and has so far produced over 0.8 × 10 9 BOE. The crude is low sulphur, waxy and sourced by Oligocene lacustrine shales. Over 200 exploration wells have been drilled from 1970 to the present, with 21 commercial accumulations discovered. Reservoirs are Oligocene to early Miocene in age with around 25% of the reserves in carbonates and 75% in fluvial-alluvial clastics. The main basins, Sunda and Asri, are retro-arc, N-S-oriented, asymmetric half-grabens situated between the stable Sunda Shield and the active volcanic arc on Java island. This paper describes the acquisition of the area and traces its history from the initial discovery at Cinta-1 in 1970, through the oil price rise and fall of the 1980s, to the discovery of a new productive basin in 1987. Exploration is not only reliant on technological advances and available budgets, so other factors relevant to the history of exploration are also included.

Ties That (Un)Bind: Families and States in Premodern Southeast Asia

Although in recent years newspapers and journals have been full of reports about family politics in the Philippines, the growing economic might of President Suharto's children and the business holdings of the Thai royal family, the “family” has only recently emerged as a subject of serious study in the historiography of Southeast Asia (McCoy 1993 and Andaya 1992 and 1994). Barbara Andaya's study of Southeast Sumatra in the seventeenth and eighteenth centuries is the first sustained examination of the significance of kinship for understanding political and economic relations in the history of any part of Southeast Asia (Andaya 1993). One of the most important reasons for the neglect of the family as a major historical topic, to extend the argument made by Craig Reynolds in a recent critique of writing on modern Thai history, is that historians of Southeast Asia generally have tended to focus less on gender or power relations in the region, and more on questions of male “power” and historical “structures” (Reynolds 1994).

An example of 3-D AVO for lithology discrimination in Widuri Field, Asri Basin, Indonesia

Abstract Drilling offshore Southeast Sumatra in the area of the Widuri Field, Asri Basin has demonstrated that the oil producing Upper Gita sandstones within the Lower Miocene Talang Akar formation correlate with bright seismic amplitudes on 3-D stack data. Seismic amplitude maps at the Base Upper Gita horizon are interpreted as either a network of distributary channels or a meandering fluvial system. Channel fill lithologies vary considerably and are difficult to interpret from conventional seismic stack data. Carbonaceous shales, likely deposited during the abandonment phase of channeling, have acoustic impedances similar to sandstones. Dipole sonic log measurements of Poisson's ratio are significantly higher in carbonaceous shales than sandstones. Based on raytraced models, carbonaceous shale has a strongly decreasing AVO while sand has flat AVO response (no change in amplitude with offset). AVO attributes P and G or intercept and gradient inverted from 3-D prestack seismic data are used for detection of carbonaceous shale. Based on mapping, good correlation exists between well data and the AVO product attribute P*G. The stratigraphic model of shale abandonment fill in a meandering fluvial system is interpreted to be supported by the 3-D AVO data. This interpretation will be tested with future drilling.

Elaeocarpus for Flora Malesiana: Notes, New Taxa and Combinations in sect. Elaeocarpus: 2

Elaeocarpus kjellbergii is described as new and the complex for which the oldest name is E. robustus Roxb. (Elaeocarpus sect. Elaeocarpus) is discussed; it includes material from the South East Asian mainland and Sumatra (described here as vars. megacarpus and collinus) together with Bornean variants here described as E. roslii subspp. roslii, opacus, bracteolatus and terajanus. Infraspecific taxa are recognized but the problems are not satisfactorily soluble in the Herbarium alone and will need a worker with extended field experience. E. longibarbatus Warb. is reduced to a subspecies under E. valetonii Hochr.

Writing the History of Southeast Sumatra: A Review Article

Writing the History of Southeast Sumatra: A Review Article

To live as brothers: southeast Sumatra in the seventeenth and eighteenth centuries

Andaya (Asian studies, U. of Hawaii) examines how the arrival of the Dutch and English impacted the relationship between two kingdoms in Sumatra, the Jambi and the Palembang, who had a long history of cyclical hostility and reconciliation. She focuses on three themes culled from legends and folklore

Does ‘jungle rubber’ deserve its name? An analysis of rubber agroforestry systems in southeast Sumatra

Jungle rubber is a blanced, diversified system derived from swidden cultivation, in which man-made forests with a high concentration of rubber trees replace fallows. Most of the income comes from rubber, complemented with temporary food and cash crops during the early years. Perennial species that grow spontaneously with rubber provide fruits, fuelwood and timber, mostly for household consumption. Jungle rubber enables lower incomes per land unit or man-day than weed-free plantations using selected rubber clones. Yet it requires much less input and labour since wild woody species protect rubber from grass weeds and mammalian predators. With a structure and biodiversity similar to that of secondary forest in its mature phase, jungle rubber belongs to complex agroforestry systems. It has accommodated increasing population densities, while preserving a forest-like environment. Yet farmers' income from jungle rubber is declining due to the exhaustion of forest reserves and reduced land availability. New research and extension options could help in improving the productivity of jungle rubber. Better transportation and marketing are needed for increasing the income from non-rubber output. Short-term, small-scale credit schemes could help farmers adopt high-yielding rubber varieties. Research should participate in creating new management methods for selected rubber based on agroforestry to reduce maintenance costs, enabling smallholders to plant high-yielding rubber at lower cost, and without losing too much of the present biodiversity and economic diversity.

Tertiary Reservoirs Offshore Southeast Sumatra--Sunda Giants Revisited: ABSTRACT

Tertiary Reservoirs Offshore Southeast Sumatra--Sunda Giants Revisited: ABSTRACT

Origin and assembly of south-east Asian continental terranes

Abstract The pre-Tertiary continental core of south-east Asia is a composite of at least four tectonostratigraphic terranes; Sibumasu (Shan States of Burma, north-west Thailand, Peninsular Burma and Thailand, Western Malaya, and north-western Sumatra), Indo-China (east Thailand, Laos, Vietnam south-west of the Song Ma-Song Da zone and Kapuchea), East Malaya (including south-east Sumatra and Natuna) and south-west Borneo. These terranes are separated from each other by sutures, and are now joined to South China along the Song Ma-Song Da zone. Stratigraphic, palaeontological, and palaeomagnetic evidence suggests that all of these crustal blocks probably had their origin on the north-eastern margin of Gondwanaland where they formed part of a complex continental margin. The Indo-China and East Malaya terranes both have typical late Palaeozoic Cathaysian floras, which indicate that they were close to South China in the Permian. Stratigraphic studies in northeast Vietnam suggest that Indo-China and South China may well have sutured as early as the late Devonian to early Carboniferous. Carboniferous and Permian faunas and floras of these blocks do not appear to be related to those of north-eastern Gondwanaland, indicating that they rifted away at some earlier time. The Sibumasu block remained on the north-western Australian margin of Gondwanaland until the late Lower Permian, and was in continuity with the Tibetan Lhasa and Changtang blocks (south of the Langcangjiang Fracture Zone) and the proto-Kreios microcontinent further to the west. Late Carboniferous and Lower Permian sediments of the Sibumasu, Lhasa, and Changtang blocks, and the Iranian and Afghan portions of proto-Kreios include extensive glacial-marine deposits. Early Permian shallow-marine faunas were of cold-water type until a major change occurred in late Lower Permian times, with Middle Permian faunas becoming typically warm-water Tethyan in aspect. It seems most likely that Sibumasu (still attached to the Lhasa and Changtang blocks and proto-Kreios) rifted from Gondwanaland in the late Lower Permian. Amalgamation of the south-east Asian blocks was probably completed by the end of the Triassic. This is indicated by terrestrial vertebrate biogeography and palaeomagnetism. It is still a matter of debate whether Indo-China sutured to South China in the Devonian-Carboniferous along the Song Ma line, or in the late Triassic along the Song Da zone. Evidence seems stronger for a late Triassic suturing of Sibumasu to the other ‘Cathaysian’ southeast Asian blocks, although a Permian closure of ‘palaeo-Tethys’ has recently been proposed for the Shan-Thai-Indo-China region. The south-west Borneo block probably rifted from the margin of Indo-China in the Cretaceous, and travelled south to its present position during the opening of the proto-South China Sea.

Commissioning and Operational Experiences of Java Seawater Treating Facility

Summary This paper summarizes the design, commissioning, and operational experiences of Pertamina/ILAPCO's Java seawater treating facility in the Southeast Sumatra Contract Area. Commissioning problems such as deaeration by gas containing 20 mol% CO2, mitigation of bacterial contamination, and water quality/suspended solids measurements are reviewed. The effects of radical pH depression on biocide requirements, corrosion rates, and oxygen seawater requirements are examined. Introduction Pertamina/ILAPCO's seawater treatment facility for Pertamina/ILAPCO's seawater treatment facility for pressure maintenance/secondary recovery of the Rama pressure maintenance/secondary recovery of the Rama field reservoir is located on Pabelokan Island. Pabelokan Island, in the Thousand Islands chain, is approximately 7 miles [11.3 km] southeast of the Rama field and approximately 55 statute miles [88.5 km] offshore and northwest of Jakarta, in the Java Sea. In Nov. 1975, crude production from the Rama field began with the Rama A satellite platform. Rama field development has continued through March 1983, with current production from nine Rama satellite platforms. A Rama reservoir model study, completed in 1980, indicated that recovery by natural depletion would approximate 80 million bbl [ 12.7 × 10 6 m3 ] of oil, or 13 % of the estimated oil in place. The study further indicated that pressure maintenance could increase recoverables by 80 pressure maintenance could increase recoverables by 80 million bbl [ 12.7 × 10 6 m3 ]. Pressure maintenance began during the last quarter of 1982, with injection into nine wells at a total rate of 200,000 B/D [31 797 m3/d] water. Suspended solids content of the treated seawater has averaged 0.01 mg/L. Water of this quality, when applied to the Barkman/ Davidson' formulas, gives an injection half-life of 6.5 years. Water Quality Requirements Millipore filter studies applied to the Barkman/Davidson equations and published laboratory/field experiences of other operators were used in developing water quality specifications. Of particular importance were injection studies done in the Brent and Forties fields of the North Sea, 2 because of similarities in seawater mineral content and reservoir permeabilities. (See the review of seawaters worldwide in Table 1.) The Rama field reservoir is composed of three limestone facies:the Lower Batu Raja (LBR) reefal,the Lower Batu Raja (LBR) marine, andthe Upper Batu Raja (UBR) reefal. Eight of the nine injection wells are completed in the UBR. Porosity of the UBR averages 23 %, with permeability ranging from 7 to 95 md. The LBR, with one permeability ranging from 7 to 95 md. The LBR, with one injection well, is of leached vuggy porosity and is highly fractured, with a porosity of 21 % and permeability ranging from 5,000 to 2 md. Java seawater was tested for solids content and plugging tendency by using Millipore filters. During the test plugging tendency by using Millipore filters. During the test procedure, 0.45 m Millipore filters were used. The procedure, 0.45 m Millipore filters were used. The filters have a calculated permeability of 14 md, which is the approximate mean permeability of the Rama field reservoir. The filter cake that forms on the Millipore membrane filter can be directly related to the filter cake that forms at the formation face and within the formation. The permeability of the filter cake is correlated, by mathematical formula (Barkman and Davidson), to the permeability of the formation, and an injection half-life permeability of the formation, and an injection half-life is calculated. Water Treating Facilities The Pabelokan treating facility was custom designed to provide water quality with a maximum suspended solids provide water quality with a maximum suspended solids content of 0.2 mg/L and removal of 95 % of all solids mu m and greater, as determined by injectivity calculations. The treating facility consists of eight major components, described in the following paragraphs. (For facility layout see Fig. 1.) Seawater Intake Sump The seawater sump, located on Pabelokan Island, is a V-shaped, concrete-reinforced Pabelokan Island, is a V-shaped, concrete-reinforced structure approximately 26 ft [7.9 m] deep, and is designed to handle 240,000 B/D [38 157 m 3 /d] water. Raw seawater is fed into the intake sump through a 36-in. 10.91-m] siphon line, which extends approximately 300 ft [91.4 m] offshore, with the inlet 65 ft [19.8 m] subsea. Hypochlorite Generator Hypochlorite, or chlorine, is injected at two locations:the inlet of the 36-in. [0.91 -m] siphon line, to prevent the buildup of crustacea, andat the seawater intake sump. The treating facility has two hypochlorite generators, one for 100% standby capacity. JPT P. 1276

Offshore Installation and Maintenance of Submersible Pumps

Verdina, G.G., SPE, IIAPCO Div. of Natomas Intl. Corp. Summary Pertamina/IIAPCO operates a large offshore production Pertamina/IIAPCO operates a large offshore production complex in the Southeast Sumatra Contract Area of Indonesia. The use of submersible centrifugal electric pumps both for artificial lift and for pipeline transfer of pumps both for artificial lift and for pipeline transfer of produced fluids has played an important role in the produced fluids has played an important role in the success enjoyed by this contract area during its 10-year producing life. This paper describes the conditions and producing life. This paper describes the conditions and considerations contributing to the initial selection and eventual standardized use of these pumps by the company. Also included are a discussion of operational experience gained and a summary of the submersible pumps performance record. performance record Introduction The operational area of the company lies in a region of the Java Sea roughly bounded by the southeastern shore of Sumatra on the west and by the string of islets known as the Pulau Seribu, or Thousand Islands, on the east (Fig. 1). In this area of relatively shallow. normally calm waters, the company over a period of 10 years has built a production/process/export facilities complex, which to production/process/export facilities complex, which to date consists of 33 platforms in 9 fields over a north-to- south distance of 30 miles (Fig. 2). Although the first wells initially were produced by natural flow. Early rapid decline in bottom hole pressures (BHP's) and production rates soon indicated the need for artificial lift. Downhole submersible pumps were introduced into the system, and eventually became an integral and standard part of all Southeast Sumatra Contract Area well completions. As of Nov. 1, 1981, 167 pumps were in service in the contract area, making this pumps were in service in the contract area, making this operation one of the largest offshore applications of its kind. Facilities Overview Produced fluids in the contract area are conveyed by Produced fluids in the contract area are conveyed by means of three-phase flow through insulated subsea pipelines from remote production satellite platforms to a pipelines from remote production satellite platforms to a central treating complex located in the Cinta field. The treatment facilities provide for gas/oil/water separation and deliver crude to a 1,000,000-bbl barge for storage and terminal export. The typical production platform in the contract area is a nine-slot, four-pile, steel template structure (Fig. 3). The platform deck is engineered to accommodate a production manifold, a well test separator, electrical production manifold, a well test separator, electrical switchgear for the submersible pumps, a hydraulic unit for the downhole safety valve system, and an emergency generator set. Power for the submersible pumps is supplied to the platform through submarine cables from the generating plant located at the central complex. Rationale for Use of Submersible Pumps The early production history of the first, naturally flowing, wells in the Cinta field indicated the need for a method of artificial lift to cope with increasingly large volumes of water and rapidly declining BHP'S. Since sufficient gas was not available for gas lifting, submersible pumps were selected on the basis ofestablished repair and replacement service facilities in the general area andlimited space requirements for pump ancillaries on the platforms. Installation of these pumps on initial completion offered the additional advantage of controlling production from the on set. thus eliminating the later need to pull completion strings and install pumps once BHP's had dropped and/or water cuts had become excessive. As the facilities complex expanded and additional remote satellite platforms were installed, the use of submersible pumps became even ignore important. Submersible pumps then became the standard mechanism for assisting fluid transmission through pipelines. In other words, a pump installed in a given pipelines. In other words, a pump installed in a given well would be designed to develop sufficient head not only to lift fluids to the surface, but also to deliver these fluids by three-phase flow to process facilities several miles away. JPT p. 222

Remote sensing applications in the Southeast Sumatra coastal environment

The coastal lowland swamps, rivers and estuarine areas north of Palembang, South Sumatra constitute a resource base likely to be extensively exploited during the next several years. Activities such as swamp forest logging, extensive fisheries, movement of government sponsored transmigrants and Buginese settlers into the area have intensified in recent years. Palembang is an important port which is difficult to maintain at sufficient depth to allow use by deep water ships, thereby creating interest in a coastal port location. In the near future it will be necessary to develop a multiple resource use management strategy based on national priorities, local needs and ecological constraints. Landforms, vegetation patterns, sediment and erosion sites, land use dynamics, settlement patterns and albedo are analysed from a time series of aerial photographs and LANDSAT imagery. The results, correlated with field data, indicate patterns of ecological constraints and resource use dynamics that have implications for development over much of the eastern coast of Sumatra.