Labuan Island Research Articles

An organic geochemical study of the Miocene sedimentary sequence of Labuan Island, offshore western Sabah, East Malaysia

Labuan is an island, located offshore west of Sabah, East Malaysia. The rocks on Labuan Island are divided into three main units; Temburong, Setap Shale and Belait formations. The relationship between these units is still unclear. An organic geochemical study was performed on ten samples from these main rock units. The main aim of this study was to determine the thermal maturity of these sediments and to differentiate between the formations based on organic geochemical parameters. The study suggests the thermal maturity is early mature to mid mature for oil generation, the Belait Formation being least mature and Temburong the most mature. Based on organic geochemical parameters and supported by vitrinite reflectance data, the Layang Layangan Unit I should be grouped within the Belait Formation. Abstrak: Labuan adalah sebuah pulau yang terletak di luar pesisir pantai di bahagian barat negeri Sabah, Malaysia Timur. Batuan di Pulau Labuan dibahagikan kepada tiga unit utama: Formasi Temburong, Syal Setap dan Formasi Belait. Hubungan di antara unit-unit ini masih kurang jelas. Suatu kajian geokimia organik dilakukan ke atas sepuluh sampel dari unit-unit utama batuan ini. Tujuan utama kajian ini ialah untuk menentukan tahap kematangan term a sedimen-sedimen ini dan untuk membezakan di antara formasi-formasi ini berdasarkan parameter-parameter geokimia organik. Kajian ini mencadangkan kematangan terma adalah diperingkat awal ke pertengahan bagi penjanaan minyak di mana Formasi Belait yang paling kurang matang dan Temburong yang paling matang. Berdasarkan parameter­ parameter geokimia organik dan disokong oleh data dari pantulan vitrinit, Unit I Layang Layangan sepatutnya diletakkan di dalam Formasi Belait.

Malaysia’s International Offshore Financial Centre: An Examination of Labuan’s Development and Operations

In 1990, Malaysia announced its plan for a regional financial centre to be established on the island of Labuan. The government invested substantial funds in providing the appropriate legislation, infrastructure, and other factors required for a financial centre. This article ex amines Labuan's history thus far, and its current operations in offshore banking, offshore insurance, trust and funds management, and tax planning. The article concludes that while Labuan has made considerable progress in improving its competitive position against other centres, significantly more investment is still required.

Labuan IOFC: The Legal Environment and its Challenges

To stimulate the financial sector further, the Malaysian government has established an International Offshore Financial Centre (IOFC) on the island of Labuan. The setting‐up of the IOFC provides new challenges for the enforcement community. Recent financial scandals involving offshore financial centres have highlighted the need to protect the IOFC from crimes and financial abuses and at the same time to ensure confidentiality is adhered to. In the paper, the Malaysian Offshore Banking Act 1990 is examined. The Offshore Banking Act, under certain conditions, allows a public officer to gain access to banking information. Stringent entry requirements are applied to banks and businesses but the bottom line is that bankers are expected to exercise responsible banking and a high standard of prudence.

Experience in Gravel Packing Long, Perforated Intervals in Deviated Holes (includes associated papers 12886 and 13309 )

Summary This paper presents the philosophy, criteria, and technique used in arriving at the gravel-packing method for Sabah Shell Petroleum Co. Ltd. 's(SSPC's) operations. It also analyzes and discusses problems and efforts to resolve them with the aid of an evaluation tool. Introduction All the gravel-packing operations were done in the South Furious field completions. The field is located offshore northwest Borneo, some 120 miles northeast of Labuan Island. The completion intervals comprise a series of inter bedded sands and shales with porosities between 20 and30% and permeabilities of 100 to 500 md. Hydrocarbon occurrences vary from 1,100 to 7,600 ft subsea (ss). Local experiences pointed out the need to gravel-pack most of the proposed completions. Previous efforts at gravel-packing intervals, typically of less than 50 ft, had been satisfactory. However, premature screen outs were noted in intervals that were initially only some 100 ft long. The difficulties increased with increasing interval length(single gross interval of 653 ft being the longest) and deviation angle(maximum of 52deg.) and also with differences in the permeabilities of the different sand layers. To understand the nature of the problem, a neutron log was used to locate the position ofthe gravel and the presence of voids. The placement technique was modified by trial and error until an acceptable technique was achieved. This paper discusses the evolution of this technique. Completion Philosophy The limited areal extent of the sands, which stacked to form very long hydrocarbon columns, resulted incompletions across large groups of sands having common pressure regimes. Two-phase vertical-flow calculations indicated optimal tubing size to be 3 1/2 in. We set 9 5/8-in. casing across completion intervals with 4 1/2- and 6 1/8-in. wire-wrapped screens(WWS) across bottom and subsequent intervals. The coupling of the 3 1/2-in. tubing restrictedthe use of the 4 1/2-in. screen to the bottom interval. The internal gravel-pack technique was preferred over under reamed gravel pack because of greater flexibility, satisfactory in flow performance (local experience), and shorter installation time. To alleviate the need for future recompletions and high work over costs. all possible oil sands were included in the initial completion. To ensure seal integrity and minimize complexity, there was a maximum of only four zones per well. Sand Failure Criteria Experience in northwest Borneo indicated that sand control is required for zones with sonic transit times At >90usec/ft. In South Furious field, this was placed at+5,000 ft ss. JPT P. 2079^

マレーシアのルバウン島における幼虫発生容器検査法によるヤブカ駆除実験の評価

A limited field trial was undertaken in Labuan Island Sabah to determine if larvicidal treatment of open containers of stored water could achieve effective control of Aedes aegypti, a vector of dengue fever and dengue haemorrhagic fever. The insecticide used was abate 1% sand granules and the method of evaluation was the single-larva-per-container method. The lethal effect on Ae. aegypti of each application of abate at a concentration of 1ppm lasted 3 to 3.5 months and was clearly reflected in the resurgence and reinfestation of the species. A higher proportion of the larvae collected from indoor containers were Ae. aegypti. Ae. albopictus larvae in outdoor water collections tended to increase markedly during the trial. The mean Breteau index of aegypti was reduced from 83.6 before larviciding to 24.7 four months after. The final Breteau index after 11 months was 10.5 and the mean premise index fell from 52.9% to 7.6%. Ae. aegypti comprized 64.8% of the larval collections, Ae. albopictus 28.3% and other species, principally Culex pipiens fatigans 6.9%. The single-larva-per-container technique provided a useful quantitative measure of the larval densities in the treated areas.

Miocene Trace Fossils from Borneo

In the Miocene Belait formation of northern Sarawak, Brunei and Sabah burrows ofOphiomorpha Lundgren were found, described here asOphiomorpha borneensis n. ichnosp. A few associated spiral tunnels of theXenohelix-type were also found. Two species ofHantzschelinia Vialov occurred on Labuan Island. A third type of structure was found in Brunei and it probably represents castings of an unknown lamellibranch. The burrows and castings were made in a brackish water environment, probably in the littoral zone of an embayment or delta.

Colour mutants of the Malay Short‐tailed Mongoose, Herpestes brachyurus Gray.

The systematic position of the mongoose named by Gray Herpestes semitorquatus, and based on a specimen collected by Sir Hugh Low on the mainland of Borneo opposite Labuan Island, i. e. Brunei, has always been somewhat of a puzzle. Very few typical specimens are known and all of these come from the distributional area of Herpestes brachyurus. The type skull in the British Museum which I have examined, shows no relevant differences from skulls of H. brachyurus of comparable age. There is also no difference in proportions, the nakedness of the soles, nor in the hair structure between the two groups. The only difference that remains is that in colour. Herpestes‐brachyurus is a very dark animal with a lot of black, whereas in H. semitorquatus the black pigment is greatly reduced, making the red ground colour predominant. The conclusion that I draw, is that the red and the blackish short‐tailed mongooses are colour mutants of the same species, the oldest name of which is H. brachyurus Gray. This conclusion is emphasized by the fact that both the black and the red mutants vary geographically, and that the characters by which “Herpestes brachyurus sumatrius” Thomas from Sumatra differs from “H. b. rajah” Thomas from Borneo, are the same as those by which “Herpestes semitorquatus uniformis” Robinson and Kloss from Sumatra, differs from H. s. semitorquatus Gray from Borneo. In both cases the Sumatran animal is more uniform in colour, with a dark tail, whereas the Bornean animal is more finely speckled, and has a tail that is lighter than the body.

XX.—Description of a new genus of Land-Shells from the Island of Labuan, Borneo

(1865). XX.—Description of a new genus of Land-Shells from the Island of Labuan, Borneo. Annals and Magazine of Natural History: Vol. 15, No. 87, pp. 177-177.

On the Geology of Labuan†

The Island of Labuan is composed of alternating beds of clays and sandstones, the former sometimes containing ironstone. Coal-seams are found in several places, and appear to be associated in groups. The principal beds of coal occur in the northern part of the island, between two ridges of sandstone hills, one of which, the most southerly and in some places upwards of 300 feet high, runs from the South Bluff of Tanjong Kubong (near the northern extremity of the island) in a S.S.W. direction to Luke Point on the western coast; and the second ridge, less regular, though at places higher than the first, commences a few hundred yards to the north of this Bluff, and runs parallel to the first ridge towards Heath Point. The beds dip conformably to the N.N.W., at angles varying from about 25° (at Tanjong Kubong) to about 70° (at Sawangan Pagar). The following is the succession of beds (in ascending series) seen in the cliffs at Tanjoug Kubong, going northward from South Kuboug Bluff:— The coal appears to be composed, for the most part, of prostrate trunks of large trees, slightly compressed, and crossing each other in all directions. The fossil wood is dicotyledonous, and exactly resembles in microscopical structure that of the Dipteraceous trees now forming the mass of timber growing on the island. What makes the resemblance of this coal to the wood of the Dipteraceae still more striking, says the author, is the existence of the thickly scattered masses of semitransparent

On the Discovery of Coal on the Island of Labuan, Borneo

Coal has been discovered near the river Gooty, on the east coast of Borneo. It resembles the best cannel coal, and burns readily, leaving a little ferruginous ash. The bed is about three feet thick, and is covered by grey shale and red sandstone. The island of Labuan consists of reefs of coral and beds of soft white sandstone with layers of blue clay. Near the north-east point of the island a bed of coal, six feet or more in thickness, has been discovered in several places. Some of this coal has been used on board the ship, and it is found to burn well and leave very little ash.