ICE 2022


This study investigates the net sand distribution of the Pliocene Forest Formation topsets of the Orinoco Delta within a section of the Southern Basin, Trinidad. The primary objectives were to understand the Forest Formation sand distribution and determine its deltaic regime by focusing on three units of interest: Upper A-B, Lower A-B and the C-D Unit, all picked from well data. To achieve this a series of steps were done as well as basic principles such as delta morphology and regime (wave-tide-fluvial) along with regressive and transgressive cycles were considered and played a major role in building this project. Before correlating wells, a 1D analysis was created to understand periods of regression and transgression. Units were picked and sand maps create, followed by deltaic regime interpretations. Facies distribution maps were also made for the same units using the distribution of well log facies which were represented by pie charts. This allowed for distinct trends to be observed regarding the distribution of specific well log characters throughout the area. Based on their associated depositional environments, an appropriate deltaic regime was then assigned, as well as estuary networks were now able to be interpreted. Next, GDE models were made for the units of interest. To justify if there were estuaries present, a sequence stratification interpretation was done for a few wells where down cut areas were compared to the networks created from the facies maps. Finally, the value of this study is such that it can be useful for future projects in terms of understanding reservoir geometry and quality since the facies analysis method gave a more detailed and defined resolution as to locating the area with the best sand. This is essential when placing a well since I learnt that despite the net sand map showing obvious sand thicknesses, it does not consider regime and the presence of estuaries which can affect flow because of there being stacked sequence boundaries. Recommendations to improve this study includes the incorporation of production data and seismic, as well as the creation of a database for the facies to test if the same results can be replicated for another delta. This study has the potential for further development as it can assist in accurately modeling GDEs and reservoir geometry for well placement.