Importance of Blocking in Petrophysical Interpretation

Proper determination of bed boundaries in layered reservoirs is vital for accurate petrophysical interpretation of conventional logs. In the wellbore, logs continuously measure physical properties of reservoir while the properties change stepwise. This continuous representation of logs may lead to ignorance of some high potential reservoir zones. The main reasons for continuous nature of logs in laminated reservoirs are the influence of shoulder beds on the reading of logging tools and low vertical resolution of these devices. In this paper we optimized a Laplacian filter to detect bed boundaries in conventional well logs. These blocking-based boundaries are validated with FMI derived bed boundaries. Then the calculated petrophysical properties including porosity and volume of minerals and fluids are distributed into the detected beds. Comparison of petrophysical interpretation of logs based on blocking and FMI derived bedding showed that the petrophysical properties realistically distributed into beds in layered reservoirs with the blocking technique. The results also showed that blocking reduces the uncertainties, because it realistically distribute the petrophysical properties inside real geological beds and alter the noises.