Automated Pattern Water Injection Optimization Using Streamline Simulation

Abstract Introducing a reservoir with multiple complexities such as faults and challenging geological characteristics, a study was catered to focus on optimizing water injection in an onshore field in the United Arab Emirates using the Pattern Flood Management (PFM) methodology. The primary goals are twofold: to maximize the utilization of available water injection resources for meeting production targets and to enhance hydrocarbon recovery. The scope encompasses a comprehensive assessment of current production and injection practices, studying the optimal distribution of water injection, evaluating injection rates for individual wells, and demonstrating the added value at both field and reservoir unit levels. The study was carried out during 2023, where two sub-reservoirs were chosen to assess optimum water injection scheme by utilizing the available water injection with the aim to meet the required oil sustainable rate targets in the short term and increase recovery. The methodology commences with an exhaustive sensitivity screening, followed by optimization utilizing the full field model. The sensitivity runs delve into various parameters' impact on PFM optimization results, with a particular emphasis on optimizing oil production. Key parameters such as Constraint Handling undergo thorough evaluation, identifying options that provide flexibility. Areal analysis is conducted to pinpoint short-term injection optimization opportunities. Subsequent optimization using the full field model underscores the criticality of selecting suitable parameters and candidate injector groups. The recommended approach for optimizing production is the implementation of pattern injection PFM over GPMAINT guide rate, which has been proven to be more effective. This strategy has led to a substantial economic gain, fully compliant with the Shareholder's guidelines, amounting to 48 MMUSD. Additionally, introducing more flexibility in injection rate limits beyond the Shareholder's guideline could potentially yield an even greater economic value, estimated at 150 MMUSD per well with higher injection than Shareholder's guideline and 650 MMUSD with increased injection volume. Moreover, areal analysis has indicated the possibility of additional injectors in the north-western flank of one of the sub-reservoirs, warranting further study to ascertain the number of wells and their precise locations. This paper showcases the outcomes of one of the sub-reservoirs that were studied, emphasizing on the importance of optimizing water injection by utilizing up-to-date technologies such as PFM. PFM technique is a powerful tool in managing the optimum water injection volumes and schemes in order to reach an ultimate goal reflecting production mandates required whilst not jeopardizing the health of the reservoir.