PALEOENVIRONMENT PREDICTION IN TARANAKI BASIN USING GEOPHYSICAL WELL LOG DATA

Abstract

The understanding of Paleo-environment involves detailed assimilation of physical chemical and biological evidences encountered during the exploration phases in search of subsurface resources. Often these evidences are not available in abundance due to lack of planning, scarcity of time or economic limitation during the exploration phases. The three basic steps involved in paleoenvironmental analysis are data collection which involved the acquisition of Well Log data, data interpretation involving the interpretation of lithofacies, and integration with other data sources (Biostratigraphic data, stratigraphic tops, Cuttings and cores data, and Mudlogs). In this work, I scanned through some six hundred and fifty wells to select nine candidate wells to interpret Paleoenvironment scenario in Ngatoro Field in Taranaki basin. The results of this study is divided into two sections: 1) Ngatoro–1 and 2) Other remaining wells. From the available data we predicted different lithological units and its environments on the basis of Gamma Ray Log shapes with the integration of other data sources. The Paleoenvironment of the Ngatoro-1 well came out to be fluvial meandering river deposit to shallow marine and marine environment of deposition. Depositional environment for other remaining wells came out to be in the cycles of transgression and regression and the depositional environment can be concluded as Fluvio-marine environment.