CONTROLS ON POROSITY IN SANDSTONE RESERVOIRS IN SOUTHERN PATTANI BASIN, GULF OFTHAILAND
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Abstract
The reservoir rock in southern Pattani Basin, Gulf of Thailand is sandstone, which was deposited in various environments from fluvial to marginal marine. This study integrated conventional core, side-wall core, wireline data, and petrographic data to recognize and better understand the factors that control porosity in this area. The porosity can be divided into 3 zones (west, central and east). The west and east zones has one porosity trend, but the central zone has two porosity trends, which has the increased porosity shift in the lower reservoir section. The central zone has better reservoir quality in the lower section than the others. The nearby fields also have two porosity trends. Compaction, clay content, and cementation are the major influences on porosity in this area, while lithology, composition, sorting, and dissolution have less impact. Dissolution enhances porosity while the others destroy porosity. Dissolution pores are normally filled or partially filled with authigenic clay. The two porosity trends in this area are probably caused by different cement agents in the upper and lower sections
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Copyright © 2008 Department of Geology, Faculty of Science, Chulalongkorn University. Parts of an article can be photocopied or reproduced without prior written permission from the author(s), but due acknowledgments should be stated or cited accordingly.
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