Eng-Tips is the largest engineering community on the Internet
Intelligent Work Forums for Engineering Professionals
-
Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
Calcium Napthanate
- Thread starter BHUX
- Start date
Hi BHUX,
This message is late, but maybe useful. Calcium Napthenates precipitate when the pressure is relieved from the oil. The reason is that CO2 then leaves the liquid, which causes the pH to increase. The solution is to process the oil at high pressure (20 barg) instead of atmospheric, possibly to dose acid.
"Trond Erik Havre" <treh@statoil.com> has worked on it, but I don't know if he can help you.
Regards,
Erik.wolff@no.abb.com
This message is late, but maybe useful. Calcium Napthenates precipitate when the pressure is relieved from the oil. The reason is that CO2 then leaves the liquid, which causes the pH to increase. The solution is to process the oil at high pressure (20 barg) instead of atmospheric, possibly to dose acid.
"Trond Erik Havre" <treh@statoil.com> has worked on it, but I don't know if he can help you.
Regards,
Erik.wolff@no.abb.com
Erik,
Your statement is not completely true as this phenomena has many faces. Unfortunately for me I had the pleasure of working on West Brae in the North Sea which has severe Calcium Naphthenate emulsion problems. What occurs is that with high TAN (Total Acid Number) crudes and produced water with even normal concentrations of sodium, calcium etc. at the oil water interface you have an extremely stable emulsion that can be up to 70% water. I have flowed this emulsion out of a separator in chunks and actually held it in my hands and you can tear it like a very heavy cloth and what you will notice is that it dehydrates very very quickly and turns ROCK HARD!! We treat with loads of acetic acid whereby the hydrophobic and hydrophilic ends of the acid chain the hydrophilic (water loving) end dips into the emulsion to bond with the water and continuously break the emulsion as the pH is contained around 5, but it only manages the emulsion as it forms just as quickly as it is broken. We let this get out of control once and filled a separator with 20 tons and had to literally chip and chisel it out not to mention undercarring it into a hydrocyclone vessel and throwing away a liner bundle.
Interesting part is that once the water cut reaches somewhere around 60% the emulsion reverses and goes away. Also Akzo Chemical manufactures this stuff and it is put into paint to help it dry and kinda makes some sense.
Jep Bracey
Flow Assurance Specialist
Marathon Oil
jtbracey@marathonoil.com
Your statement is not completely true as this phenomena has many faces. Unfortunately for me I had the pleasure of working on West Brae in the North Sea which has severe Calcium Naphthenate emulsion problems. What occurs is that with high TAN (Total Acid Number) crudes and produced water with even normal concentrations of sodium, calcium etc. at the oil water interface you have an extremely stable emulsion that can be up to 70% water. I have flowed this emulsion out of a separator in chunks and actually held it in my hands and you can tear it like a very heavy cloth and what you will notice is that it dehydrates very very quickly and turns ROCK HARD!! We treat with loads of acetic acid whereby the hydrophobic and hydrophilic ends of the acid chain the hydrophilic (water loving) end dips into the emulsion to bond with the water and continuously break the emulsion as the pH is contained around 5, but it only manages the emulsion as it forms just as quickly as it is broken. We let this get out of control once and filled a separator with 20 tons and had to literally chip and chisel it out not to mention undercarring it into a hydrocyclone vessel and throwing away a liner bundle.
Interesting part is that once the water cut reaches somewhere around 60% the emulsion reverses and goes away. Also Akzo Chemical manufactures this stuff and it is put into paint to help it dry and kinda makes some sense.
Jep Bracey
Flow Assurance Specialist
Marathon Oil
jtbracey@marathonoil.com
- Status