Acidizing The Fundamentals

Acidizing

Damage Assessment

worckover &completion commonalities

uFluid is put into the wellbore and/or formation

u

uTubulars of some sort are run into the well

Fundamental Acid

 uWellbore clean-up (tubing/casing)

uMatrix acidizing (sandstone or carbonates)

uAcid fracturing (carbonates)

Types of Acid

uMineral

–Hydrochloric - HCl

–Hydrochloric/Hydrofluoric - HCl/HF

uOrganic (slower reacting – less corrosive)

–Acetic

–Formic

uPowdered (acid sticks)

–Sulfamic

Chloroacetic

Wellbore Clean-up

uClean-up

–Mill scale

–Corrosion scale

–Pipe dope

uPickled tubing

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The Pickle Job

uMinimum volume of aromatic solvent – 250 gallons

uScale basis 0.1 lb/ft in 5 ½” 20# casing (or 0.003” of 5.0 sg magnetite mill scale)

–400 gal/1000’ 5 ½”

–100 gal/1000’ 2 7/8”

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u15% HCl

uMinimum CI

uAromatic solvent  pre-flush

uNo iron control

u

uCatch return samples