Production engineers frequently use back allocation to estimate actual production volumes from wells based on frequent well test data or theoretical calculations using well and reservoir characteristics. PETRONAS executed a centralized production data management system from early days of production to establish a scalable and reliable workprocess among the organization. The production and operation data management system of the field supports data collection, QC, validation and production back allocation as well as production downtime optimization. The new system provides a means to visualize complex networks, verify the production streams, track gathering systems functionality through time and derive the allocation networks. The various downtime coding and quantifications, helped Petronas to quantify the root cause of production shortfalls and optimized the unwanted shut downs. The new system has improved the data quality and reliability and has made the data transparently available to the various stakeholders in the organization. After the new back allocation system became fully operational, Petronas started to realize the following benefits from this successful implementation. Determine the production quantities of each well and reservoir for production accounting.Quality check and approval for the test data before being used for further calculationsAbility to allocate production, where accurate measurements are not possible or cost effective.Ability to determine fluid flow quantities through every strategic point in the network The current paper describes the challenges and benefits of the subjected system implementation.

This paper describes the workflow where wells and production network (15 platforms and 100 active wells located in the Cheleken Block offshore Turkmenistan) are automatically modeled daily in a steady state and transient tools to finally be analyzed in a web based surveillance system. Contributing in the daily well production surveillance, optimization and core field operational processes like flushing and pigging pipelines, dewaxing wells, etc. The Cheleken Block Central Data Gathering System (CDGS) was fully integrated with steady state and transient models (wells and network). These models are updated and run automatically on daily basis from the CDGS. The close monitoring of the frequent routing diversion of wells and flowlines, separators, flares, etc. was solved with the implementation of a workflow to automate the updating of these routing in the database and in the Field Network models, enabling proper rollup of production, feeding into the transient model and analyze results in a web based integrated surveillance tool. The implemented tools and workflows improved production surveillance and analysis with the gained comprehensive insight into the operations through overall asset. Analysis and reporting of performance indicators including trends of actual production against plan, downtime analysis and other operational workflows in a reduced timeframe compared with conventional methods of analysis. The implemented web based integrated surveillance tool provided a single way to integrate operations from a broad range of disciplines with cross domain workflows and integration with different software and systems. This integration, allowed to dramatically reduce the time of analysis of models results from weeks to hours. This was possible with the automation all manual tasks in a single environment. This paper details the implementation of integrated field surveillance and modeling workflows which can be assessed on daily basis. This integration was implemented using open source concept allowing multiple engineering software and databases (from different vendors) to operate simultaneously