TGP is owned by El Paso Energy which operates a coast-to-coast natural gas pipeline system. TGP operates three interstate pipeline systems that serve 20 states, principally in the Northeast and Midwest. TGP supervises all three pipelines (about 16,000 miles of pipe and more than 70 compressor stations consisting of 1.5 million horsepower) from a single control center.

Four controllers operate the entire system. In seeking additional ways to help the controllers operate the pipelines in a safe, reliable and efficient manner, an expert system was identifie d that could help controllers meet operational objectives. The original goal for the expert system was fuel minimization. However, as the project evolved, programmers realized that only imagination, time and money limited the expert application. Consequently, operating consistency, improved reliability and safety were placed on an equal footing with efficiency. As with all analytical systems, data integrity is a critical issue. Gas controllers and engineers have developed several techniques for resolving inconsistent data and replacing erroneous data with reasonable values "on-the-fly".

The company applied Gensym’s object-oriented expert-system programming language as a tool for maintaining and improving quality and reliability in pipeline operation. The company created a small team of gas controllers and engineers to develop ProCA.

The controllers’ pipeline operating knowledge is re-created in the expert system in the form of rules and procedures in ProCA. One expert programmer, supporting the gas control room, adds information to the ProCA knowledge base daily. The result is a dynamic, constantly improving system that not only supports the controllers in their operations but also facilitates the writing of special studies for the communications, marketing and measurement and transportation planning departments. The ProCA’s development focus was in the following areas:

• Alarm management
• Pipeline efficiency
• Reliability
• Fuel efficiency
• Development, documentation and education
• Real-time volume balancing
• Unit operating efficiency
• Data integrity.

ProCA’s development and implementation has helped Tennessee Gas and Pipeline in numerous ways. "With ProCA, there is no need to wait until an alarm is triggered. The company strives to alleviate potential situations before they reach the problem stage. ProCA not only warns the controller when a parameter is moving in an undesirable direction, but it also suggests possible changes based on past experiences of the best controllers. This improves efficiency, reliability and safety, states Anders Johnson, an engineering consultant for the Tennessee Gas Pipeline Facility and Capacity Planning Department.

This story was condensed from an article published on the Pipe Line & Gas Industry Web site. Click here to read the entire article.