Dynamic Reservoir Uncertainty Evaluation for Production Delivery Assurance

A new production development scheme was proposed for one of the major offshore fields in the Gulf. To assist building assurance of the delivery of this scheme, subsurface uncertainty evaluation was initiated; firstly based on an in-house approach and later through the use of commercial softwares. The proposed study is primarily focused on dynamic reservoir uncertainties. The objective of this study is to evaluate the impact of the reservoir uncertainties on plateau duration period in the prediction phase. The workflow, based on experimental design and response surface, advantages and outcomes of this study are presented and its limitations discussed. This study was completed over a short period of time, thanks to an optimization of the CPU resources. This was a key advantage obtained while carrying large models with long history exceeding 50 years. The study resulted in successfully delivering probabilistic profiles (P90, P50, P10) in order to assure the production delivery of the proposed development scheme and enables to develop risk mitigation plans. A ranking of the most influential uncertainty parameters with quantification of their interactions is obtained. Consideration is also given to the history match quality, which results in reducing the parameters distributions and highlights the value of the data acquisition.