The call came in at 9pm UK time. Our site engineer reported that the live leak test was going ahead. On a frosty night in January, I drove to the office in Stockton, to meet up with the rest of the team. Across the globe, in a warmer and more humid climate, a team from Oil Search in Papua New Guinea were preparing to remove product from an oil pipeline to establish the viability of the latest technology in which they had recently invested. This paper describes a shared experience: the successful implementation of a model based solution for leak detection using a new liquid model, a team spread out over four continents and how a simulated pump was used to reduce false alarming across an open valve with an abnormal pressure lift! The team had been working for several weeks to commission the leak detection system and had faced a fist-full of problems. ESI's creative engineers worked with Oil Search and produced a flexible model based solution that overcame problems with data outages, spiking pressure measurements and other abnormal measurements. Now all of that effort would be tested. Oil Search's previous Rupture Detection System used two methods:
Comparing differences in calculated mass of oil into and out of the pipeline, allowing for packing, in 30 second time frames.
A differential flow alarm if the line pressure fell and the differential rate of flow was greater than 2,000 BPD Oil Search performed a leak test on this system in August 1994 with satisfactory results.
However, it was accepted that during normal operations of start-up and shutdown, false alarms were experienced. This paper addresses:
Benefits of a model based leak detection system
Flexibility of using a model based leak detection system
How advanced analysis tools can identify optimum leak detection sensitivity for all operations
Procedures for performing a live leak test
Problems overcome during the project implementation
The benefits and pitfalls of a globally diverse team
Oil Search Limited (OSL) is an oil and gas exploration and development company that have been operating in Papua New Guinea (PNG) since 1929. It is PNG's largest oil and gas producer, and operates all of PNG's producing oil and gas fields. In 2006, Oil Search was responsible for generating 16% of PNG's gross domestic product and 22% of its export revenue. As PNG's largest oil and gas producer, Oil Search moves over 16 million barrels per year through 168 miles (270 km) of pipelines between its Central and Gobe processing facilities and its Kumul Marine Terminal, where product is loaded onto ships. Crude oil is periodically moved in 650,000 barrel batches (103,350 m3)
