Hydrofluoric Acid 2

[jmcgrath]

Dear All,

Does anyone know if Hydrofluoric Acid is used in any well bore treatments such as acidising, or is there any way that it can be naturally occurring in a well bore?

Regards,

John McGrath

 

[samlukeben]

Hydrofuoric Acid is normally produced from a mixture of Fluorospar and Sulphuric Acid and subsequent fractional distillation process. On this basis I would assume HF is not naturally occuring. It is classed as a "weak" highly undissociated acid which will attack glass or silica on contact. It is used for acid fracs when appropriate, depending on the formation type.

Hope this helps..

 

[pa24pilot]

I spent a summer with Schlumberger-Dowell and we used Hydrofluoric Acid in acid jobs from time to time. I think it was for wells that had sanded in.

 

[ArtLift]

Hydrofluoric acid (HF) is used routinely in sandstone acidizing. It's one of the staples of the stimulation industries. However, I have not heard of natural occurances in the wellbore.

 

[malkibs]

HF can used for matrix acidizing or acid fracturing and it used only with sand but with low concentrations in some well it may damage the reservoir. In addition, HF has strong effect on sand and metal that might cause corrosion in drill pipe or coil tubing.

 

[arbo]

usually hf is used when silicates are present in order to dissolve them

 

[rguill5]

This is often called "mud acid" or "clay acid". We used it sometimes when we are encountering a real shaly sand with a lot of damage. Most people try to stay away from it b/c it often causes upsets with the processing system.

 

[arbo]

hf is mostly used to dissolve silicates however a combination of hf with some acid blends gives good results in elimination of sulphates or other non carbonates deposits which cause a lot of trouble in drilling

 

[bnw]

Iam sure HF use for sand stone formation

 

[johnchrc]

I know of a job coming up where 28% HCL is being pumped into sandface to try and improve skin and productivity. It is common stimulation fluid.

It is not naturally occuring in fomrations but I'm no expert.

 

[JAFCO]

HF acid is most common in "Mud Acid" Packages, depending on the service provider the mud acid mixture can very significantly but commonly a mix of 15% HCL, 5% HF, and corrosion, antislude, and Iron Control additives. The use of Mud Acid to clean up perforation tunnels immediately after completion is quite common. The key factor in using HF acid in sandstone reservoirs is the timely removal of spent acid. If the HF acid spends on quartz, and is allowed to remain in the formation the quartz can precipitate out of solution again and form an insoluable product that can be very damaging

 

[Yashoo]

Be careful if you use HF. If it contacts your skin it will remove calcium from your bones unless a special injection is administered.