Cleaning Recommendations

Cleaning Recommendations as generated on: 03/28/23

Based on the data that you have input, the following recommendations are provided for cleaning well
“ww”.
The well is to be treated with a solution of NuWell-110 Granular Acid or NuWell-120 Liquid
Acid in combination with NuWell-310 Bioacid dispersant. The NuWell-310 increases the acid’s capability
to effectively remove the mineral scale and any biological material. The NuWell-310 will also reduce the
crowding that occurs on the reactive surface by keeping material in suspension and increasing acid
activity at the molecular level. In addition to the above NuWell-310 acts as an inhibitor to protect the
well materials and tooling during the well cleaning process. The NuWell-400 will help with deeper
penetration of the chemistry into the formation for better cleaning.

The treatment volume is calculated based on the input data also keeping in mind, the need to treat the
well casing, gravel pack and formation using appropriate chemicals and their concentrations at a
cleaning pH level of 3 or less during the treatment process.

Effective cleaning of the well is achieved by pushing the treatment fluids into the formation and allowing
the treatment fluids to react with the well blockage. This can be accomplished as follows:

Physically clean the inside of the well by removing any loose scale deposits. This can be done by brush,
jetting or other methods. Evacuate all of the loose material from the well after physically cleaning the
well.

A solution of 40% of the total treatment volume of clean, potable water (400x 0.4 = 88 gallons) should
be used to mix with the recommended treatment chemicals in the tank on the surface. The mixing tank
should have a capacity of at least 20% greater than the volume of solution to be mixed in the tank in
order to avoid spilling during the mixing and transfer or the chemials can be mixed in multiple batches.
Blend the acid into the water (not the water to acid); then add the NuWell-310 Bioacid dispersant and
NuWell-400 non-ionic surfactant, again and blend thoroughly.

Place 75% of the cleaning solution across the screen section by spotting it with a double surge block and
swabbing the solution into the screen. Also wash the casing with the cleaning solution in the well to help
clean the upper non-wetted portion of the casing.

Check the pH at 0.5 to one hour intervals especially in the beginning to be able to maintain a minimum
pH of 3.0 in the cleaning solution in the well. If the pH rises above 3, add approximately half of the
remainder of the cleaning solution to the well. After about 10 to 20 hours spot the remainder of the acid
solutions in the screen section and work it into the formation. Allow the solution to remain in the well
for a minimum period of 24 to 48 hours.

The well should be periodically swabbed to move the cleaning fluids into the formation to facilitate
cleaning. Use deliberate stroking to push volumes of cleaner into the area outside the screen.
Occasionally check the pH of the treatment solution and add an additional quantity of acid whenever
needed to maintain the pH near 3.

After the cleaning solution has worked in the well for at least 24 to 48 hours, pump the acid to a waste-
holding area and neutralize it prior to discharge.

If the well shows sign of mechanical blockage due to sediment infiltration or if the produced water is
exhibiting elevated occurrence of very fine sand, silts and clays Johnson Screens also recommends that
after a well has been cleaned, and all of the cleaning fluids have been removed, the well be redeveloped
using NuWell-220 Clay Dispersant. NuWell-220 can be swabbed into the formation for 2 to 12 hours to
remove clays and fines, especially in older wells that have either not been properly developed or that
fines are migrated due to disintegration of the formation.

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Recommendations