Scale squeeze 1

[john1964]

Dear fellow engineers.......
I would like information on scale squeeze performed on oil producers to prevent scaling of the sub surface & surface equipment.
**What is the best combination of chemicals to be used?? Best recipe which will give a prolonged scale treatment?
**What is the best soak time???
**What is the pump in pressure & treat rate to be used, such that it has minimum damage to the reservoir & also surface equipment. The tree is a 5K tree.
**Do we have software for use of squeeze returns so as to prioritize the scale sqeeze tratment??

 

[DrillerNic]

I'm afraid this is a "how long is a piece of string" question!

The combination of chemicals depends upon what your scale is... salt, calcium carbonate, barium sulphate, asphaltenes...the worst scale to deal with is typically barium sulphate. It's not uncommon to pump a cocktail or chemicals, say a mutual solvent to make the scale water wet, an acid for calcium carbonate and some kind of chelating agent for barium sulphate.

The soak time again depends upon what you're trying to get rid of. Generally shorter is better, as you'll have less deferred oil!

Pump pressures and rates all depend on where you are trying to get the treament to, and what the wellhead and sand face pressure are: if you just want to treat the top 1000ft of tubing then the pressure will less than if you want to get the treatment to the bottom of the tubing at 10,000ft or whatever.

As for prioritising the scale treaments, I've worked at companies where they only did scale treaments when they noticed that production for a particular well had declined, and other places where they did regular preventative scale treatements according to a scale growth calculation using regular analyis of produced fluids. 6 and two 3's I think!

Speak to the likes of Petrolite, Roemex, Well Flow International and see what they try to sell you!