FILL REMOVAL FROM HORIZONTAL WELLBORE USING FOAM IN COILED TUBING

Coiled tubing is extensively used in oil industry to clean the wellbore to increase
the productivity of oil/gas well by removing the fill/sand downhole. Well cleanup
operation for large diameter well with low bottomhole pressure is problematic and
common cleanout fluids are not effective as a circulation fluid due to severe pressure
losses and low suspension capability. In order to mitigate such effect, foam is used as
a circulation fluid because it has the highest suspension power. Foam is formed by
mixing water, air and additive. Due to complexity of foam rheology, it is challenging
to accurately predict foam-solids flow behaviour during coiled tubing cleanout
operation.