Optimal sidetrack time evaluation by segmented proxy model

Sidetrack operations which involves accessing a new zone and commingling production gives rise to
uncertainties and proxy models have shown to be able to incorporate uncertainties and mimic real-life
scenarios to an acceptable degree of accuracy. In this paper, a time-based proxy model which integrates the uncertainties that emerge as a result of several reservoir parameters was developed using
NPV as the objective function. A black oil simulator was used to generate the production profile and
NPV computed using certain economic parameters. The Box-Behnken response surface design was
used to generate a combination of variables with which the experiment was carried out. Non-linearity
of the NPV which was caused by the impact of time was corrected using segmented regression and the
split design was based on visual observation of the main effect plot. The segmented proxy models
obtained were reasonable to an acceptable degree of accuracy in mimicking the simulation model.