Many phenomena in pipeline operations exhibit two phase characteristics, such as slack line, liquid formation, wet gas operation, separation processes, etc. In order to correctly simulate these operations it is important to have a transient two phase model. This paper will outline the two phase model used on the Trans-Alaska pipeline and provide comparisons to slack he data provided by the Alyeska Pipeline Service Company. The transient involves starting the pipeline at tight line conditions. Pressures in the pipeline are then reduced to create slack line conditions. After operation in this region the pressures are increased to recover the tight line condition. The paper will provide comparison of pressure, flows and void to actual pipeline operation data, and will include a transient demonstration of the slack line formation and recovery. The paper will also discuss the application to other two phase operations.
Alyeska Pipeline Service Company is responsible for operation and maintenance of the
Alyeska was formed in 1970 to design and build the pipeline, and act as agent for the seven companies which own the Trans-Alaska pipeline. From 1969 to 1977 a work force of about 70,000 people joined forces to construct the pipeline that required 515 Federal permits and 832 State permits at an approximate cost of $8 billion. The Alyeska Pipeline Service Company is a consortium of BP Pipelines, ARC0 Transportation Alaska, Exxon Pipeline, Mobil Alaska Pipeline, Amerada Hess Pipeline, Phillips Alaska Pipeline, and Unocal Pipeline. Trans.Alaska Pipeline The Trans-Alaska pipeline is one of the largest pipeline systems in the world. Its design and construction is considered to be one of the most difficult engineering feats of our time. The pipeline carries crude oil from Prudhoe Bay and other oil reservoirs on the North Slope, over 800 miles of rugged Alaskan mountains, rivers and harsh terrain to Valdez - the northern most ice-free port in North America. (Fig 1) Building a pipeline from the Arctic had never before been achieved, and operating it in such an isolated region is a continuing challenge. The United State depends on the Trans-Alaska pipeline to deliver more than 20% of its domestic oil production, Without this vital link to North Slope oil fields, the entire nation would be affected. Alyeska Pipeline Service Company has the tremendous responsibility of keeping this oil flowing in a safe, efficient, and environmentally sound mamrer. To do this Alyeska is at the forefront of technologies and regulations. The latest is the purchase of an advanced training simulation to allow the training of controllers to better understand the operation of the pipeline during normal and abnormal operating conditions. Overview of Two phase Model SimSuite PipelinerM is designed to be extremely flexible pipeline modeling tool, allowing it to handle the wide variety of pipeline systems in the pipeline industry. It has components for calculating the dynamics for Gas, Product and Crude oil Pipe lines.