ABSTRACT
Wax deposition endangers the flow assurance and safety of pipeline especially for crude oil with high wax content (high waxy crude oil), which contains up to over 25.0wt% wax content in China’s submarine pipeline. Present work aims to study the deposition behaviour of a high waxy crude oil in cold finger and flow loop. The deposit mass and thickness, under various temperature differences (wall temperature 30℃, oil temperature 40-50℃), rotational speeds (100-300rpm/min) and deposition time (1-9h), was determined gravimetrically using cold finger. Deposition results in cold finger were then converted to calculated deposit thickness under flow loop condition with Weispfennig model[1-2] based on Chilton-Colburn analogy, and further compared with the experimental deposit thickness from flow loop. Results indicate that the converted deposit thickness (from cold finger) is comparatively thinner than the measured thickness in flow loop. A hypothesis is proposed that wax crystal precipitation and latent heat release must not be neglected for high waxy crude oil, where Nusselt number considering Stefan number[3] and precipitated crystal amount for phase change material[4-5] is introduced into the Weispfennig model.
Figure 1. Comparison between converted deposit thickness (from cold finger) and thickness measured from flow loop experimental value (A1-A3: Original model result, B1-B3: Model with Nusselt number for phase change material)
References
[1] Weispfennig K. Advancements in Paraffin Testing Methodology[J]. SPE International Symposium on Oilfield Chemistry, 2001,2:13-16.
[2] Couto G H , Chen H , Dellecase E , et al. An Investigation of Two-Phase Oil/Water Paraffin Deposition[J]. SPE Production & Operations, 2008, 23(01):49-55.
[3] Dhaidan N S , Khodadadi J M . Melting and convection of phase change materials in different shape containers: A review[J]. Renewable & Sustainable Energy Reviews, 2015, 43:449-477.
[4] Kong M , Alvarado J L , Terrell W , et al. Performance characteristics of microencapsulated phase change material slurry in a helically coiled tube[J]. International Journal of Heat & Mass Transfer, 2016, 101:901-914.
[5] Andreas H . Numerical study of flow-through wall elements with phase–change materials[J]. Journal of Building Engineering, 2018,20:105-113.
Wax deposition endangers the flow assurance and safety of pipeline especially for crude oil with high wax content (high waxy crude oil), which contains up to over 25.0wt% wax content in China’s submarine pipeline. Present work aims to study the deposition behaviour of a high waxy crude oil in cold finger and flow loop. The deposit mass and thickness, under various temperature differences (wall temperature 30℃, oil temperature 40-50℃), rotational speeds (100-300rpm/min) and deposition time (1-9h), was determined gravimetrically using cold finger. Deposition results in cold finger were then converted to calculated deposit thickness under flow loop condition with Weispfennig model[1-2] based on Chilton-Colburn analogy, and further compared with the experimental deposit thickness from flow loop. Results indicate that the converted deposit thickness (from cold finger) is comparatively thinner than the measured thickness in flow loop. A hypothesis is proposed that wax crystal precipitation and latent heat release must not be neglected for high waxy crude oil, where Nusselt number considering Stefan number[3] and precipitated crystal amount for phase change material[4-5] is introduced into the Weispfennig model.
Figure 1. Comparison between converted deposit thickness (from cold finger) and thickness measured from flow loop experimental value (A1-A3: Original model result, B1-B3: Model with Nusselt number for phase change material)
References
[1] Weispfennig K. Advancements in Paraffin Testing Methodology[J]. SPE International Symposium on Oilfield Chemistry, 2001,2:13-16.
[2] Couto G H , Chen H , Dellecase E , et al. An Investigation of Two-Phase Oil/Water Paraffin Deposition[J]. SPE Production & Operations, 2008, 23(01):49-55.
[3] Dhaidan N S , Khodadadi J M . Melting and convection of phase change materials in different shape containers: A review[J]. Renewable & Sustainable Energy Reviews, 2015, 43:449-477.
[4] Kong M , Alvarado J L , Terrell W , et al. Performance characteristics of microencapsulated phase change material slurry in a helically coiled tube[J]. International Journal of Heat & Mass Transfer, 2016, 101:901-914.
[5] Andreas H . Numerical study of flow-through wall elements with phase–change materials[J]. Journal of Building Engineering, 2018,20:105-113.
Presenter(s)
Once the content has been viewed and you have attested to it, you will be able to download and print a certificate for PDH credits.
If you have already viewed this content,
please click here
to login.