Harnessing Benefits of Integrated Asset Modelling for Bottleneck Management of Large Offshore Facilities in the Matured Giant Oil Field

Abstract

Abstract An offshore giant oil field in Abu Dhabi is producing from multiple developed reservoirs with large offshore facilities including complex subsea pipeline network. However, due to increasing associated gas and water production trend, facility capacity can be insufficient in the future. Therefore, it is challenging to achieve planned oil production target. This paper demonstrates how to achieve it with cost effective mitigation method and IAM (Integrated Asset Modelling). To achieve the objective, following organized methodology was applied. 1. Production network system modelling through history matching with the actual field observed data. 2. Integrating standalone reservoir models, production network and existing facility capacity constraint. 3. Simulating the model with specific field control method. 4. Analyzing the profile to identify the bottleneck for each period. 5. Preparing several debottlenecking options. 6. Assessment of the cost and impact on profile by debottlenecking options. 7. Proposing the most cost effective debottlenecking solution to achieve planned oil production target. Several bottleneck issues of the existing facilities were identified through the modelling work; capacities of offshore complex separation, flaring, gas export, water processing, and gas dehydration. IAM shows those capacity constraints may cause oil production short-fall without proper management. In addition to that, friction in the subsea flowlines are also concerned because it increases back-pressure for production wells. Therefore, several mitigation options were evaluated and optimum solutions were prepared for each issue such as additional gas export line installation, converting existing subsea line to flowline, unhealthy well shut-in and additional well potential requirement, change of subsea network configuration. The study with IAM concludes all of those bottleneck issues can be mitigated by those debottlenecking options. One of the IAM benefits is to enable us to evaluate production potential by bringing together existing information and models from all parts of the production system. It revealed various bottleneck issues within the existing giant offshore complex facilities. And it also showed how those issues can be managed by proper mitigation measures.