Research On Creeping In The Offshore Pipeline And The Determination Of Its Track

China's offshore petroleum exploration & exploitation are making great progress. The offshore pipeline is dominating means to transport oil and gas, and its basic requirement is safety and high efficiency. The offshore pipeline inspection has been given more and more attention. But there is no offshore pipeline inspection unit at present in China. The research on creeping technology in the offshore pipeline and the determination of its track has been made under the support of the National High Tech Research and Development Program(863 Program) to break the overseas technological blockage and solve the technical problem of our offshore pipeline inspection.This paper analyses and summarizes the creeping and positioning technology both domestic and abroad, concerning against the characteristic of our country's offshore pipeline. Two sets of technological schemes with respective features were researched and proposed: combining the in-line inspection together with the position measuring which driven by electric creeper, and combining the ultra-low frequency electromagnetic signal positioning technology together with intermittently moving in-line.Concerning about the position measuring which driven by electric creeper, magnetism test was made. The electrical crawler, trouble-rescuing butt structure and their intelligent control system also have designed. On the basis of the above-mentioned technical research and emulational test, the simulation prototype has bee triumphantly developed. A set of designing technology of electrical creeper in offshore pipeline has come into being.Under the support of the National High Tech Research and Development Program Youth Fund, the real-time positioning test with ultra-low frequency electromagnetic signal has been made. The in-line intelligence leading device and offshore pipeline determining system have been researched and designed. The systemincorporates the strong points of global positioning system, inertial navigation system and ultra-low frequency real-time positioning system. The offshore pipeline determining system characterized by high precision, long- distance -inspecting and independent of the interval reference points of pipeline, etc. The research has been checked and accepted by experts of in October 2004.The technology of creeping in the offshore pipeline and determining of its track will play an important role in the safe running of our offshore pipeline.