Smith said he arrived one morning about 30 years ago at a construction site outside Tulsa, Oklahoma, and saw a frightened calf dash out of an unfinished oil line. “Ive heard stories of deer and other animals cleaned out during construction,“ said Smith, president of Texas-based Inline Services. Smith and others in his niche industry spoke on Thursday about the importance of flushing out pipelines and the widely available technologies that London-based BP PLC could have used to prevent damage that halved production this summer at Prudhoe Bay, the nations largest oil field. “Were always trying to improve. Were here to share successes and misses and were here to learn,“ said BP spokesman Daren Beaudo. “Thats our objective today, to fully take advantage of all the expertise in the room.“ BP failed to regularly clean some of the lines in the field on Alaskas North Slope with spool or bullet-shaped devices known as “pigs.“ The British oil giants operational lapses were discovered after a spill in March--the North Slopes largest--and a smaller spill in August that prompted the company to cut Prudhoes 400,000 barrel-a-day output to less than 200,000 barrels a day. Production has returned to 400,000 barrels a day, the company said Thursday. BP operates the field on behalf of two other major owners, Exxon Mobil and ConocoPhillips. One speaker urged the audience of more than 100 oil field engineers and managers, and state environmental regulators to build pipelines that can accommodate cleaning pigs. The North Slopes aging pipelines are difficult to pig because of sharp turns. Elevation changes cause water and debris to collect at the base of inclines. Pipelines are fat in some places and skinnier in others. They are harder to clean because the pig must fit the diameter of the pipe. “If you can make it piggable, make it piggable,“ said Derek Clark, a business development manager for BJ Process and Pipeline Services Company. “Dont experiment with your pipeline.“ Representatives from a handful of international pipeline maintenance companies came to the conference hosted by the state Department of Environmental Conservation, BP and ConocoPhillips. Larry Dietrick, who directs the states Department of Environmental Conservation, said Governor Frank Murkowski called for the technical conference after the August spill. The state will be using information from the meeting to craft regulations on 1,500 miles (2,400 kilometers) of pipelines on the North Slope, Dietrick said. Meanwhile, the federal Department of Transportations Office of Pipeline Safety is writing regulations for the 16 miles (26 kilometers) of transit lines that BP will replace because of leaks. Steve Marshall, president of BP Exploration Alaska Inc., has said the company had believed its corrosion control program, which costs millions annually, was adequate. He said the company runs more than 350 pigs a year on other lines previously deemed more vulnerable to corrosion than the transit lines. Oil is pulled from the ground and goes to a flow station, which removes impurities that can cause corrosion--water, gases such as carbon dioxide, hydrogen sulfide and oxygen, and solids. With those materials removed, Marshall said, the company did not expect corrosion to be so severe in the transit lines. All kinds of deposits can build up in a line, everything from sand, wax and scaly calcium carbonate, to salt water from oil extracted offshore. The material can slow the flow of oil down a pipe and can shield varieties of bacteria that corrode the metal. Many operators turn to pigging only when a problem is apparent, a practice that can lead to safety and environmental risks, or jeopardize a multimillion-dollar pipeline. PIN/AP