19. Acid Jobs That Do Not Work.

Acid treatments which fail to stimulate production have usually been troubled by one
or more of the following problems :
1. Using acid on formations which are inadequately perforated, or on
sandstones which are not damaged.
2. Using the wrong type of acid to remove the damage.
3. Using dirty water in the preflush or overflush.
4. Lack of Hydrochloric Acid Preflush when using Hydrofluoric Acid with
sandstones.
5. Inadequate mud acid volume, minimum volume should be 50 gallons
per foot of pay.
6. Lack of immediate clean-up with mud acid, even with acid post-flush,
allows deposition of precipitates.
7. Failure to clean the acid or water tanks.
8. Additive misuse or overuse.
9. Fracturing sandstones with acid (except with very small volume
perforation breakdown treatments).