With the aim to fulfil a more comprehensive and effective water injection optimization strategy in a giant carbonate reservoir, the asset carried out a dedicated study for a giant carbonate unit (Unit-M) to evaluate the specific challenges and define mitigation actions to improve the reservoir performance.
This paper outlines the experience of the successful integration and strong collaborative environment between Reservoir Management Surveillance-Studies, Water Handling, Optimization and Production Operations teams through the project execution leading to optimal solutions in a short period, in accordance with a long-term plan oriented to effectively manage future injection requirements. These actions allowed a favorable impact on the operating costs associated to the new and more efficient water balancing.
Water injection, oil production, and reservoir pressure performance in addition to surveillance data for Unit-M have been analyzed at region and well scale. A better-detailed understanding about Peripheral and pattern injection Balance using streamline simulation and material balance analysis provided the support to implement actions that include: reactivation of the pilot pattern WI wells, redistribution of Water Injection in the periphery, maximize the efficiency of the Water injectors (Roll Up, re-utilization in other units, P&A) and Optimize clusters utilization. Moreover, the reservoir simulation was used to verify the impact of the new Water Injection strategy in pressure maintenance, sweep efficiency and the ultimate recovery expected.
The conformation of a dedicated task force team between Water Handling Operations and Development teams enable the alignment to common goals and a successful integration that led to define short term actions and mitigate present challenges of waterflood reservoir management. Effective and timely application of these solutions resulted in significant reduced maintenance cost (+/-30%) of the wells and clusters involved.