Analysis and Optimization of Zama Field Development Using Integrated Production System Modelling

Abstract The Zama field, located offshore of Mexico, is one of the world's biggest shallow-water oil discoveries in the past 20 years. The field has recoverable volumes of over 700 MBBL of oil. The development plan will include 2 production platforms, 29 oil producers, and 17 water injectors with two 66 km long pipelines to carry the oil to an onshore facility. Given the significance of this field, the use of an IPSM (Integrated Production Systems Modelling) can provide an increased value from this development through better design and operational decisions. The reservoir has conventional 28 °API oil, located in a thick pay with a significant geothermal gradient - Which will have an impact on the performance of the waterflood as water properties will change with temperature. This requires thermal capability in the reservoir simulator. The wellbore and facilities models, including all relevant completions and equipment, were built in a steady-state integrated production system module, that is capable of handling any fluid model. For this project, thermal black oil in both reservoir and facilities was considered the right approach as it will have a better simulation performance than full EOS models. The integrated simulation used explicit coupling between the reservoir and production models, with a "smart" coupling frequency chosen by the integration tool. The workflow allows for multi-fidelity solution to IPSM - and this was utilized in areas such as well and pipeline models where there was a choice to use pressure drop correlations or pipe tables. Even though this is a greenfield development, the analysis had shown that water injection should begin from the start of field development. The base IPSM considered all these aspects, and was optimized for performance. Thereafter, the production and injection strategy (constraints, rates, scheduling, etc.) as well as the overall completion and facilities design (well tubings, pumps, pipeline, risers, etc.) were optimized in an integrated fashion - providing a range of outcomes from the chosen schemes. The workflow yielded a stable IPSM system capable of predicting long-term performance of the Zama field development plan. The workflow was able to integrate subsurface and surface disciplines on a collaborative platform, which drastically reduced the logistical and workflow inefficiencies that exist in traditional IPSM workflows. The advanced fluid handling capabilities, with thermal black oil models in both reservoir and production system proved valuable to enhance the predictability from the model. The workflow captured the complex interactions between facilities and reservoir and the entire system was optimized using a novel end-to-end uncertainty management framework.