Experimental investigation of hydrodynamic slug mitigation potential of an intermittent absorber

• Published in: Chemical engineering research & design 2016-09, Vol.113, p.50-60
• Main Authors: Ehinmowo, Adegboyega B., Ogunleye, Oladipupo O., Orodu, Oyinkepreye D.
• Format: Article
• Language: English
• Subjects: Choking; Hydrodynamic slug flow; Intermittent absorber; Slug attenuation
• ISSN: 0263-8762
• DOI: 10.1016/j.cherd.2016.07.006

[Display omitted] ⿢We present a new method for stabilising hydrodynamic slug flow in pipeline-riser system.⿢We present theoretical background and proved the concept through experimental and numerical studies.⿢We built stability maps and bifurcation maps showing the influence of the mitigation device.⿢We proposed a method for quantifying stabilising benefits due to the device. The need to handle hydrodynamic slugs in a more efficient way becomes important as oil and gas activities shift deep offshore. This study describes the use of a vessel coupled to the pipeline-riser system upstream of the first stage separator for hydrodynamic slug attenuation. The experiments were carried out in a 2⿳ pipeline-riser system which comprises of a 40m long horizontal pipe connected to a 11m high vertical riser followed by a 3m horizontal topside section. Air and water were used as experimental fluids. Bifurcation maps and slug attenuation index (SAI) have been used to quantify increase in oil production and the slug attenuation potential of this concept. The device was observed to reduce the pressure fluctuations characterising hydrodynamic slug flow up to 22%. The device also provides additional benefits of stabilising the flow at higher valve opening (choke setting) and lower pressure compared to traditional choking. This in practice translates to increase in oil production. Special case of hydrodynamic slugs which exhibit overchoking induced slugging (OIS) was also observed to be relatively attenuated by the introduction of the absorber.