Integration of sequence stratigraphy, rock physics and AI inversion to determine the prospective reservoir in the shelf environment of the Tarakan Basin, Indonesia

The Tarakan Basin is one hydrocarbon basin in Indonesia with approximately 40 discoveries and more than 1000 MBOE reserves. This study discusses an approach to integrate the sequence stratigraphy, rock physics and acoustic impedance (AI) inversion analysis to determine the prospective reservoirs in the basin. PRG-1 well data is used in the sequence stratigraphy and rock physic analysis. The sequence stratigraphy analysis of PRG-1 shows that there are three system tracts: transgressive, low stand tract and high stand system tracts. The integration of sequence stratigraphy, rock physics and log data analysis show that the prospective reservoir interval in PRG-1 well is located at a depth of 4730-4780 feet. It is characterized by low gamma ray, low NPHI, low density and high resistivity. The prospective interval was deposited in early Pliocene as Tarakan Formation in the low stand system tract of shelf depositional environment. The AI map shows that the distribution of the prospective is around the PRG-1 and in the eastern part of the area.

ECOLOGICAL ANALYSIS OF GELAM (Melaleuca cajuputi) ON PEATLAND IN SOUTH KALIMANTAN

Until now the raw material of wood especially Gelam (Melaleuca cajuputi) for supporting the construction of housing and other infrastructures is increasingly demand in Indonesia. On the Island of Borneo that partly consists of peat swamps needs Gelam very large and continuous, particularly for residential development. Ecological aspects are very important for supporting the silvicultural strategies. The aim of this study is to analyze ecological aspects which are very influence especially physical and chemical soil properties and microclimate as well. The utilization of study is to determine the silvicultural strategies for continuing production and conservation of Gelam in the future. The method was used a field survey around Gelam forest and did collecting samples and measuring there. The results showed in South Borneo the potency of Gelam is only 2,9-7,1 m3/ha and decreasing yearly. Normally Gelam with a diameter <4 cm have been cut down, as well as > 30 cm. Gelam can grow on the peat swamp forest where the soil was low pH 3.5-3.9. Most of pH of soil in these areas was influenced by phyrite (FeS2 of 0.4-2.2% and highest of Fe 90-302 ppm. C organic in the soil was included low-moderate 5.5-10.0%. Result of soil physic analysis showed composition of sand, dust, and clay of 9 : 54 : 57 % respectively. Temperature and humidity around peat swamp forest areas where was found Gelam were 31-33oC and 63-73% respectively. Most of areas around Gelam were grown Gelam Tikus (Syzygium inophylla) and some kind of shrubs.Key words: Gelam, potency, ecological aspects, silviculture