Scrutiny of Porosity information from Well-log in the South Eastern Niger Delta Region

Raw well data from oil wells J and K in some parts of the Niger Delta were used for estimating porosity in sandstone and shale units. Porosity is seen as an important parameter for estimating the appreciable volume of hydrocarbons and other fluid content that may be accessible in the reservoir. Gamma ray log and sonic log with respect to depth were generated using Microsoft Excel for analysis. The results of these suites of log were used to estimate porosity. The major outcomes resulting from the porosity estimates revealed that the average porosity values are about 35% for well J and 30% for well K. This study shows that the increase in sonic transit time gives rise to an increase in porosity irrespective of the lithology. However, sonic transit time decreases with increase in depth; depth having a strong coefficient of determination of about 0.9 with temperature, implies an increase in temperature also leads to a decrease in porosity. The Depth-Temperature relation shows T = 0.0228D + 16.671. The porosity which has been obtained in the study is appreciable as it is in the excellent class. Also, a Porosity-Transit Time Equation has been obtained. This model satisfies and improves porosity estimates irrespective of the value of sonic in microsecond per foot for the South Eastern part of Niger Delta Basin.