oa Volumetrics Analysis and Field Development Planning

The process of estimating hydrocarbon-volumes-in-place is usually based on a probabilistic approach<br>that integrates whatever reliable and relevant data such as geologic/ geophysical interpretations, well<br>log and core data is available. This approach makes use of the prior (statistical) knowledge of<br>parameters such as prospect area, reservoir thickness, porosity and permeability - the intrinsic<br>parameters. The result is a probability (or cumulative-probability) distribution for a range of volumes;<br>companies typically report the 10%, 50% and 90% probable hydrocarbon volumes.<br>For field development purposes, we further exploit this approach to plan the exploitation by analysing<br>which intrinsic parameters “dominate” along different parts of the S-curve, or in other words where to<br>find the “quick wins” (pick the lower-hanging fruits first) and leave the more risky parts of the field for later.<br>The method comprises three steps: i) sensitivity analysis, ii) generating a range of scenarios and iii)<br>generating a development-risk map for the field.<br>The method will be illustrated by results from an actual field development project.