Maximizing The Value of Simulation Models by Effective Geological Updates – A Successful Strategy for a Complex Offshore Saudi Arabian Oil Field

Nieto, Jorge E.¹; Sultan, Ahmad J.; and Miller, Randy W.
¹[email protected]

Optimized updates of geological and simulation models allow for the generation of pragmatic and opportune scenarios for field development in a timely manner based on adequate operational conditions, best practices, and management requirements. The availability of this methodology allows for incorporation of the latest newly acquired data, such as local structural updates and logging information. The workflow developed in this study facilitates updating an existing geological model with newly acquired data that prolongs the usefulness of a dependable geological model. Full implementation of this process will provide the most up to date, accurate model available for effective field evaluation and development.

This approach applies primarily to mature fields with robust data sets where new information does not deviate drastically from adjacent domains. The process assumes that conceptual stratigraphic, sedimentological, structural, fluid, and initial dynamic conditions are still valid. This methodology was applied to an integrated study in a major oil field in Saudi Arabia which has undergone extensive reservoir simulation. The workflows followed to update the model at history match level were used to evaluate development strategies in a very complex and heterogeneous interval. The model was continuously updated with newly acquired data and the results utilized to optimize well placement (laterals) according to simulation forecasting. Modeling and simulation results were evaluated based on cumulative oil production, ultimate recovery, and/or production acceleration.

A tangible advantage realized from this practice has been the increased percentage of reservoir contact (NTG ratio) obtained in recently drilled wells. Since the model is monitored and updated based on pilot wells, and final well paths are designed and planned according to geological and dynamic-simulation evaluation, better drilling results are expected . Keeping models alive by effective and practical updates greatly aids in our understanding of a complex, highly heterogeneous reservoir. This reduces uncertainty in geological factors, drainage anomalies and productivity issues. If a model has a solid framework built by a multi-disciplinary team with robust interpretations, it is our task to keep such a complex model functional, avoiding characterization re-launching which creates a disruption of the synergism needed to formulate effective development strategies for the field.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013