The series of shaker screens to use in the analysis was chosen after testing many mud samples. It assures that plugging will not occur. The procedure developed for ascertaining the amount of each particle size down to 44 microns, using shale shaker screens, is outline in the below.
- Take a representative 500-ml sample of mud.
- Evaporate the liquid from the sample without boiling.
- Leach dry sample with hexane if oil was used in the original mud.
- Redry without boiling.
- Weigh sample
- From the result of step 5, the amount of solids in 500 ml, calculate the amount of solids in the 2 gal samle to be analyzed.
- Take a representative 2 gal sample of the mud.
- Pour the sample slowly through the shale shaker screen with dilution if necessary. Note: If any slurry fluid leaks out bwtween shaker screens the sample must be discarded and a new sample processed starting at step 7. Shaker screens recommended are the U.S. standard Nos. 6, 10, 12, 25, 60, 100, 200, and 325.
- Dry the solids on the shaker screens with care to avoid loss of fine particles that may fall through the screen when sample is dry.
- Wash the dry residue on the shaker screens with hexane if the original mud contained oil.
- Redry the mud sample.
- Vibrate the dry samples again on the shaker screens for 5 minutes at medium frequency.
- Weigh the dry solids on each shaker screen.
- Collect all throughput material below the 44 micron shaker screen (No. 325) that was involved in the steps 8 through 12.
- Take a representative 500 ml sample of the throughput and calculate the equivalent solids in the total throughput volume as outlined in steps 4 through 6.
- As a check on step 15, subtract the weight ogf solids on the shaker screens (step 13) from the amount of solids in the initial 2 gal sample (step 6).
(Weight of solids in 2 gal sample) – (weight of solids on the screens) = weight of solids smaller than 44 microns.
Check with: weight of solids smaller than 44 microns by sample analysis(step 15).