Risk Analysis for Integrated Asset Modeling to Support Decision-making: A Real Case Application

Abstract

This paper shows a field application of the risked-based approach to an innovative tool based on a biogenetic algorithm for the integrated production optimization of surface facilities. The tool was applied to analyzed different solutions available in the PLEM configuration for a new well tie-in. Uncertainties related to a planned acid job on a well of the system has been taken into account in order to compare the probabilistic results of the analyzed configurations.The described tool has the ability to integrate in a unique environment the whole production system, handling a high number of optimization variables simultaneously. In the first phase, the integrated optimization process with genetic algorithm takes place. The result is an optimized field configuration characterized by a deterministic production increase. In the second phase, after having identified the uncertain input variables in the optimization process, a Monte Carlo simulation for the optimized field configuration is performed. The result is a probabilistic distribution of the production increase. Different PLEM configurations have been compared on the basis of the probabilistic results obtained. The integrated production model was developed for a FPSO treating the production from different subsea oil wells. An additional well was planned to be connected through an existing PLEM to the FPSO. Different configurations were analyzed to connect the well and the deterministic results from the optimization have been compared. Additionally, an acid job was planned for one of the wells in the system. The risked-based approach has been used to compare the different possible configuration to be applied, taking into consideration also the statistical distribution of the productivity index expected after the work-over. The probabilistic results obtained for the different configuration studied were characterized by a defined level of confidence and were used as a support in the decision making process for the tie-in of the new well.The tool is able to take into account uncertainties related to work-over on wells and to evaluate different scenarios with a desired level of confidence. Results from the study show the strength of the presented innovative risked-based approach to the integrated asset modeling, as a tool to support the decision making process.