Pre/post-production uncertainty analysis applied on the Hyme field

Abstract

The objective of this master thesis is to quantify how the estimated uncertainty, associated with the Hyme field, will change as more data becomes available. This will be done by identifying the key uncertainties and comparing the pre/post -production estimated ultimate oil recovery and hence the long term potential of Hyme. Hyme is classified as a fast-track development, which means that limited technical subsurface work has been performed before the production start-up. There are limited data available, and no cores where taken. The objective was achieved through a process that involved three major tasks. The first task was to adjust geologic and reservoir simulation models to establish a working reservoir simulation model and to generate a model reference case to be used in the uncertainty analysis. Secondly, a stochastic pre-production uncertainty analysis was performed in order to quantify the range of ultimate estimated oil recovery and the governing parameters that affect this. The final task was to perform a post-production uncertainty analysis, which utilizes actual bottom hole pressure data with a computer assisted history matching process. The study concludes that the uncertainty associated with the Hyme subsurface was reduced with early data. Based on the results of the pre-production uncertainty analysis, the ultimate estimated oil recovery can be described within the range of 3.40 to 5.44 million Sm3. The post-production uncertainty analysis resulted in a range of 4.01 to 5.21 million Sm3. Hence the uncertainty range for the ultimate estimated oil recovery and the risk concerning the long term potential of Hyme was reduced.