Salt/Chlorides ppm or gpg
The salt or chlorides concentration of the mud is monitored as an indicator of contamination. The salt contamination may come from water used to make mud, salt beds or from saline formation waters. The test is conducted on mud filtrate.
One or more milliliters of filtrate is added to a titration dish and 2 or 3 drops of phenolphthalein solution is added. Drops of 0.02 nitric or sulfuric acid solution are then added while stirring to remove the pinkish color. One gram of pure calcium carbonate is then added and stirred. Next, 25 - 50 ml of distilled water and 5 - 10 drops of potassium chromate solution are added. This mixture is stirred continuously while drops of silver nitrate solution are added until the color changes from yellow to orange red and persists for 30 seconds. The number of milliliters of silver nitrate used to reach the end-point are recorded. This is then used in the equation:
Chlorides(ppm) = (ml of silver nitrate x 1000) / ml filtrate
This can be converted to salt (NaCl) ppm by multiplying the chlorides by 1.65, or to grains per gallon by multiplying the salt ppm by 0.0583.
The salt or chlorides concentration of the mud is monitored as an indicator of contamination. The salt contamination may come from water used to make mud, salt beds or from saline formation waters. The test is conducted on mud filtrate.
One or more milliliters of filtrate is added to a titration dish and 2 or 3 drops of phenolphthalein solution is added. Drops of 0.02 nitric or sulfuric acid solution are then added while stirring to remove the pinkish color. One gram of pure calcium carbonate is then added and stirred. Next, 25 - 50 ml of distilled water and 5 - 10 drops of potassium chromate solution are added. This mixture is stirred continuously while drops of silver nitrate solution are added until the color changes from yellow to orange red and persists for 30 seconds. The number of milliliters of silver nitrate used to reach the end-point are recorded. This is then used in the equation:
Chlorides(ppm) = (ml of silver nitrate x 1000) / ml filtrate
This can be converted to salt (NaCl) ppm by multiplying the chlorides by 1.65, or to grains per gallon by multiplying the salt ppm by 0.0583.
