Uncertainty Management in the Development of MOT Reservoir, X Field, Niger Delta

Abstract

MOT reservoir has a unique case of uncertainties as a result of data paucity being in a field where no production has occurred, and there is need to reduce the uncertainties associated with the key evaluation parameters required for making investment decisions. This paper presents how a multidisciplinary team resource was leveraged on in managing the identified uncertainties to deliver a robust development plan for the reservoir of interest. The approach deployed emphasize on integration and collaborative interpretations from the constituting disciplines in the study team. Early focus was placed on uncertainty identification, quantification and management. Iterative efforts were necessary to achieve consistency of results and preservation of physical meaning as the study moves from one domain to another. A consistent framework for quantifying the respective impacts of the identified uncertainties was developed, and realizations were constrained by the most impacting parameters to generate a probable representation of the subsurface. Subsurface development concepts were tested and suitably selected to optimize recovery using the base case realization as a control, and preliminary economic evaluations were also performed to determine the project robustness to risk and the magnitude of the investment. The experience from this work provides a reliable approach to handling the development of a green field reservoir with limited data availability. An approach to overcoming several limitations on how to predict a fit-for-purpose PVT-table, developing a representative SHM were also presented, and the success obtained further emphasize the advantage of integration in a multidisciplinary team. The results showed that the high impacting uncertainties were structure, fluid contacts, and relative permeability, and the identified uncertainties were managed by building realizations to adequately capture the possible outcomes, and the preliminary project economic evaluations suggests that the project would be viable even for the Low-Case outcomes, hence adding value to the company portfolio.