BAKER HUGHES - Drilling Fluids Reference Manual

Water Based Drilling Fluids
Cement Contamination
MAX-SHIELD Additions
MAX-SHIELD Concentration
MAX-PLEX Concentration
MAX-GUARD
Concentration
Although PERFORMAX is tolerant to cement contamination; drilling cement may
cause depletion of the MAX-PLEX . Citric acid is recommended as a treatment for
cement contamination to maintain pH at 10.5 to 11.5. If the system is not displaced,
hardness should be reduced below 400 mg/L with soda ash, and MAX-PLEX
filtrate concentration should be checked by FSE. Increased MAX-PLEX treatments
may be required in response to cement contamination.
The particle size of MAX-SHIELD is very small and additions of MAX-SHIELD
can cause a viscosity increase due the material effectively acting like a low gravity
solid in the system. Always pilot test before adding MAX-SHIELD and other
products to the system. Additionally, the rate that MAX-SHIELD is added to the
system should be from 15 – 20 minutes per 55-gallon drum. The actual rate should
be adjusted after pilot testing and monitoring viscosity as the material is added to the
system.
MAX-SHIELD should be maintained at 2% to 4% by volume at all times. The
MAX-SHIELD concentration should be monitored at all times using the
concentrations tracking program on ADVANTAGE Drilling Fluids reporting
package.
The MAX-PLEX concentration is measured by a fluoride selective electrode (FSE)
method. The rate of MAX-PLEX depletion is related to drilling, dilution and
formation consumption rates. Variables effecting the depletion of MAX-PLEX
include: 1) rate of penetration, 2) hardness levels and 3) pH levels.
MAX-GUARD is a liquid clay hydration suppressant that provides superior clay
inhibition and low dilution rates. The recommended concentration of MAX-
GUARD is 2 - 3% by volume, and will vary based on hole size, rates-of-penetration
and reactivity of the formation being drilled.
Handling recommendations for MAX-SHIELD
• All MAX-SHIELD containers which have been opened should be added to the mud.
Partially-full containers of MAX-SHIELD should not be returned to warehouse.
• Containers of MAX-SHIELD should not be exposed to extremely cold temperatures or
allowed to freeze.
pH Level Recommendation: The pH should be maintained, using caustic soda (NaOH) at 10.6
to 11.3 at all times, while the optimal pH is 11.0. The pH should be monitored at the flowline
frequently, particularly when drilling at high rates-of-penetration or when adding products that
reduce pH and/or deplete MAX-PLEX. The pH electrode should be calibrated with buffers at pH
7.0, 10.0 and 12.5. Measurement of mud pH should be performed on a 50/50 dilution of whole
mud with de-ionized water or whole mud using a high salinity electrode.
Recommended Lubricant: TEQ-LUBE and MIL-LUBE are recommended lubricants for this
system. Recommended treatment is 2 to 3% by volume. If other lubricants are to be used, pilot
tests should be conducted before the product is added to the mud system. In general, water
soluble products will be more compatible with PERFORMAX.
Acid Gases: Lime or gypsum additions, in combination caustic soda, can be used to treat carbon
dioxide contamination. Be sure to check the concentration of MAX-PLEX in the system
whenever treating with lime or gypsum, since these products deplete the aluminum component in
MAX-PLEX. Gypsum may also cause some flocculation of the fluid, but this can be corrected
with treatments of 0.5 to 2 lbm/bbl of ALL-TEMP.
MIL-GARD may be used for hydrogen sulfide intrusion.
The PERFORMAX system may be prepared for various applications with salinity as high as
saturation for compatible salts. Actual formulations can be adjusted to meet specifications for
Reference Manual
Baker Hughes Drilling Fluids
3-98 Revised 2006