Technical Papers

SUPERCRITICAL FLUID FLOW IN PIPELINES – A DENSE PHASE CASE STUDY

There is a discontinuity in the tabulated thermodynamic properties as the fluid is going across the critical point. In this paper, utilizing regularization techniques, correlations are established to continuously determine fluid properties during the transition through the critical point and into the supercritical region.

PERFORMANCE OF CPM BASED LEAK-DETECTION ALGORITHMS IN THE PRESENCE OF SLACK

Leaks may occur at any time and location in a liquid transmission pipeline. One of the significant complexities in the leak detection process arises when the leak happens in a pipeline in the presence of phase change. A set of experiments are conducted on a 374-meter (1227-ft) pipe to examine the performance of CPM-based Leak-Detection algorithms.

A MATHEMATICAL MODEL FOR THE SPATIAL PREDICTION AND TEMPORAL EVOLUTION OF THE COLUMN SEPARATION IN A FLOWING HYDROCARBON TRANSMISSION PIPELINE

A novel model is used to predict the inception moment and location of a phenomenon known as the column separation or slack line. The existing models for prediction of the cavitation phenomenon in internal flow systems in general are primarily formulated for the capture of the inception moment and initial location of the event only. Hence questions such as where the incepted cavities and bubbles tend to go, or the detailed state of a slack line in time should be addressed using a different approach.

COLUMN SEPARATION IN A SHUT-IN LIQUID HYDROCARBON TRANSMISSION PIPELINE

Crude oil transportation pipelines depend on Computational Pipeline Monitoring (CPM) systems for leak detection. Accurate prediction of the volume of vapor phase in the pipeline is very challenging when crude oil goes though phase change (column separation) in the pipeline. It is also challenging to accurately predict the vapor phase volume when the pipeline is started from extended shut-in period during which thermal cooling or heating can occur depending on the season of the year. Pipeline operators rely on the accuracy of CPMs to make decisions on column separation and to avoid the masking of a leak during column separation. The column separation can happen due to heating and/or cooling during extended pipeline shut-in, or due to elevation changes or due to flow transients.