L51554 Field Observations on the Two-Phase Hovenweep CO2 Gathering System During Summer Operation

While laboratory-scale studies of single-phase flow have resulted in good correlations for the design of large-diameter pipeline systems, similar approaches for two-phase flow have not been as useful. Although theoretical modeling and simulation of single-phase turbulent flow has not yet been accomplished, empirical observation of many small-scale examples has lead to effective correlations through dimensional analysis. These correlations for a single-phase often do scale-up adequately for design of pipelines. However, when an additional phase is present, this approach has not worked well. It is likely that a better understanding of the fundamental interaction of two-turbulent phases will be necessary if small-scale studies are to be used for the design of large, high-pressure pipeline systems.

A more immediate way of gaining some knowledge of two-phase flow in large diameter pipes of the complexity present in the field is to over-design a pipeline system and construct it, field tune it to specifications, then observe its behavior. This is obviously a risky and expensive approach. However, many such systems have been constructed. It is on these successful two-phase pipeline systems that our attention should be focused in the immediate future if we are to improve two-phase pipeline design now of new but similar systems. Such is the focus of this study of the Hovenweep CO2 Gathering System.

The Hovenweep CO2 Gathering System was selected for study as a pipeline system that could add to the knowledge of the nature of steady-state two-phase flow in large diameter high pressure pipeline systems with hilly terrain. Characterization includes measurement of the following variables: 1. gas and liquid flow rates; 2. typical gas and liquid compositions; 3. liquid volume fractions; 4. pressure drop across each test segment; 5. temperature.