Effects of Pressure on Low Liquid Loading Two-Phase Flow
Duc Voung, Research Assistant, Ph.D. Candidate
Low liquid loading is a widely encountered phenomenon in wet gas transmission pipelines. Understanding of low liquid loading is essential to proper pipeline and downstream facilities design and management of chemicals used for flow assurance purposes such as corrosion inhibitors. Several studies address the experimentation and modeling of two phase low liquid loading flow. However, they are typically limited to flow in small diameter pipes for low pressure conditions. In this study, low liquid loading gas-oil flow experiments will be conducted in a newly constructed 6-in. ID high pressure flow loop. This new large pipe diameter and high pressure facility is suitable to investigate the effects of pipe diameter and pressure on two-phase and three-phase flow behaviors.
In this study, the oil phase is Isopar L mineral oil because of its low viscosity and low specific gravity which are similar to properties of a typical gas condensate. The oil density corresponds to 760 kg/m3, while viscosity and surface tension are 0.0013 Pa.s and 0.024 N/m. The gas phase is nitrogen due to its relatively low safety risk. Nitrogen density and viscosity at different temperatures and pressures are obtained from Span et al. (2000) and Seibt et al. (2006), respectively. The main parameters to be investigated in this study and the associated instrumentation are:
- Flow Pattern and Visual Observation
- Canty Tubular System
- Wire Mesh Sensor
- Pressure Gradient
- Differential Pressure Transmitters
- Liquid Holdup
- Quick Closing Valves (QCVs) and Canty Tubular System
- Wire Mesh Sensor
- Wetted Wall Fraction
- Canty Tubular System
- Wire Mesh Sensor
- Droplet Entrainment
- Iso-Kinetic Sampling
- Wave Characteristics
- Wire Mesh Sensor
The test matrices of this study are as follows:
- Superficial oil velocity: 0.01, 0.02, 0.03, 0.04 and 0.05 m/s
- Superficial gas velocity: varying from 3 to 17 m/s depending on the operating pressure
- Operating pressure: 1.48, 2.17 and 2.86 MPa (200, 300 and 400 psig)
Experimental results will be used to evaluate and improve the available models and correlations.