Forward_C: A Refinery Scheduling System based on CHIP
FORWARD_C provides a single interactive environment to address Crude Scheduling, Process Unit Scheduling, Blending and Offsite Scheduling. It combines the expertise of the refinery scheduler and the power of a semi-dynamic, event-driven simulator to evaluate scenarios (either user-supplied or automatically modified by expert rules) and generates warnings (e.g. levels exceeding thresholds, hydraulic limit violation) and guides him to take proper action, who always remains in full control of the system.
FORWARD_C simulates refinery operations for a few days to several weeks. It foresees inventory variations for crudes, components and finished products based on the latest information (e.g. stocks, estimated dates of receipts and liftings, planned shutdowns). Over a span of a few days, the user defines a production scenario and generate operational instructions to be processed either manually (process units) or automatically (e.g. movement data handled by an Oil movement system). By bridging the gap between production plans and daily operations, it enables the user to give detailed operating instructions without loosing track of optimum mid-term plans. Users can identify potential problems and dynamically modify the scenario to react quickly to events like production deviations or changes in vessel arrivals or market demands.
LONG TERM USES
FORWARD_C can also be used for longer term horizons (i.e. 1-3 months) and shows trends (inventory variations, product pools evolution, production modes) to support the Marketing department in preparing the Supply and Lifting programs, which have long lead times.
It also provides valuable on-line information to the trader, when facing unexpected business opportunities, by checking that sufficient ullage is available for receipts and sufficient products are available on time for shipment.
Standard Forward_C Modules
FORWARD_C Network Configuration Module defines the model of the physical plant to be scheduled. This is supported by a library of standard refinery process units, connected by streams.
FORWARD_C Simulator Module computes yields and other physical properties of the process units within the model defined in the preceeding module.
FORWARD_C Scheduling Manager to develop the schedule and iterate through different scenarios.
FORWARD_C Data Exchange Module: built around ORACLE, it interfaces FORWARD_C with the refinery database.
FORWARD_C Initial status Module: prepares stock inventory, such as tank levels and stock qualities at the beginning of the scheduling period.
FORWARD_C Blending Module: using various linear and non-linear blending laws, this module computes optimal blends with different objective functions. It also allows users to relax conflicting constraints.
FORWARD_C Rule Editor allows the refinery scheduler to create/update rules that are triggered when special events occur. These rules define actions the system has to take.
Additional modules have been developed on demand to cover more advanced requirements such as crude tank allocation optimization, optimization of crude mixture to topping.
Ease of integration
FORWARD_C complies with de facto standards like UNIX, XWINDOW, SQL and TCP/IP. Although FORWARD_C can be used in a standalone mode, it runs typically as a part of a Refinery Information System. The user retrieves the previous schedule, imports data from the refinery database and enters only a limited amount of data. Similarly the results of FORWARD_C can be exported to the refinery database to be used by other applications.
Due to the large amount of data that it manipulates, FORWARD_C provides its full capabilities when integrated in a refinery information system.
FORWARD_C: an advanced productivity tool for refinery operations
FORWARD_C technology applies advanced artificial intelligence and optimization techniques to remove the burden of repetitive tasks so that the user can concentrate on solving the core problems that require human intervention.
FORWARD_C is fully integrated with CHIP. Logic programming techniques combined with Constraint Solving help in keeping simple the definition of complex problems and in limiting the area of investigation, thus reducing the computation time.
FORWARD_C's rule editor enables users to define his own set of expert rules using a very flexible grammar system with a large vocabulary based on the full refinery model. Expert rules offer the possibility to increase the productivity of the user, by automating many of the otherwise-manual tasks.
FORWARD_C has been installed and is in regular use at the following sites:
- FINA, Refinery at Antwerp, Belgium,
- ERG Petroli, Refinery at Syracuse, Italy,
- BP, Refinery at Lavera, France.
TECHNIP designs and builds industrial and service facilities in a large range of sectors: production and processing of hydrocarbons, petrol-chemicals and fertilisers, industry infrastructures etc.
Number One in France in Engineering and Construction, TECHNIP is second in Europe.
- Worldwide : 5600 people
- Business Turnover : US$ 1.98 billions (1996)
Major operational bases in France, Italy, Malaysia, Abu Dhabi, Russia, Venezuela, Columbia and Brazil.
Authors: F. Glaisner, L.M. Richard