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Structural development and complex basin forming mechanism in Pattani Basin may have formed naturally fractured basement reservoirs. The basement of the South Pattani Basin is poorly understood, as a result of low seismic resolution in its deeper part and lack of wells that reach the basement. Hence, seismic interpretation may improve the understanding of South Pattani Basin basement fracture systems. This paper aims to investigate the geological and seismic characteristics of the fractured basement reservoir, identify the relation between basin evolution and fracture network and development, and proposed a play concept for naturally fractured basement reservoir. Seismic attributes exhibit prominent N-S fault and fracture trends in the study area. Three basement high areas revealed that open fractures distribution identified using seismic ant-tracking technology has good correlation with regional maximum horizontal stress direction (N-S), but the intra-basement (central) area exhibits strong alignment with pre-existing fabrics (NW-SE). Open fracture networks in Zone A and B developed around major fault swarm features. Integrated qualitative and quantitative seismic analysis suggests that the three basement high areas have the potential for fractured basement reservoirs, with a complex fracture configuration and development due to poly-phase deformations. [ABSTRACT FROM AUTHOR]

We examined temporal variability in benthic metabolism and nitrogen (N) cycling in the subtropical Brunswick Estuary, Australia from December 2000 to December 2002. Benthic metabolism was tightly coupled to the production of labile carbon (C) in the water column (phytodetritus) and temperature, both of which increased in summer, resulting in increased rates of benthic metabolism and a shift to sulfate reduction. C : N ratios of remineralized material showed a consistently low return of N relative to 'Redfield'-type material over the 2-yr study period (up to 84 : 1 and averaging 31 : 1). The highest remineralized C : N ratios occurred at a sediment C[O.sub.2] productivity/ respiration of ~0.4, which corresponds to maximum respiration and maximum productivity, and also when water-column dissolved inorganic nitrogen concentrations were lowest, reflecting potential N limitation. The 'missing N' was most likely assimilated by heterotrophic bacteria and autotrophic benthic microalgae (BMA). Extracellular organic carbon extruded by the BMA and subsequently decomposed may also account for some of the high remineralized C : N ratios. Net [N.sub.2] effluxes were controlled by a complex interaction between the supply of N[O.sup.-sub.3] from the water column and nitrification, the supply and decomposition of labile C, benthic productivity, and macrofauna abundance. A N mass balance for the sediment over the 2-yr study period showed that a significant proportion of the mineralized nitrogen may have been removed from the microbial loop and passed up to the metazoan levels of the food chain. About 22% of the remineralized N was permanently removed via denitrification. This active competition for limited N resources between heterotrophs, autotrophs, and chemoautotrophs appears to be a mechanism by which N-limited oligotrophic subtropical estuaries tightly recycle and conserve N.