BAKER HUGHES - Drilling Fluids Reference Manual

RESERVOIR APPLICATION FLUIDS
• 0.94 bbl of brine (no KCl)
• 1 gal/100 bbls X-CIDE 102 (25% by volume glutaraldehyde)
2. Optional Barrel Formulation:
• W-306 (5 or 55 gallon) @ 2.00 gpb to YP= 20
• 1 MIL-CARB (50 lb bag)
• 2 to 3 ppb Magnesium Oxide to buffer pH = 8.0
• Brine volume to 1 bbl
• 1 gal/100 bbls X-CIDE 102 (25% by volume glutaraldehyde)
Displacement
Prior to building or loading the PERFFLOW system, all pits and lines should be cleaned and
flushed with water/seawater. Cement and float equipment should be drilled with the existing fluid
prior to displacing the hole with PERFFLOW. Best results can be achieved if the hole can be
circulated with seawater prior to the PERFFLOW displacement. The circulating rate should be as
high as possible with pipe rotation to minimize channeling. Pump a 25 to 30 barrel caustic pill
followed by a 25 to 30 barrel high viscosity (3 gal/bbl W-306) pill then follow with the
PERFFLOW system.
Open Hole Displacement for Completion
At total depth, a short trip to the casing should be made and a high viscosity 25 barrel pill pumped
and circulated to surface. The drilling assembly should be pulled out of the hole and a hole opener
picked up and washed to bottom. The hole and casing can be displaced with a filtered completion
fluid at this time. A 20 barrel pill with 3.0 gallons per barrel W-306 in water should be pumped to
separate the two fluids. If any tight hole was experienced or concern for lost circulation exists, a
PERFFLOW polymer pill (W-306 without calcium carbonate) can be spotted to cover the open
hole plus 500 ft inside the casing. In this case, the workstring should be pulled 250 ft inside the
casing. The casing is then circulated until clean brine is returned to the surface. Pull the hole opener
out of the hole, then rig up and run in the hole with the completion assembly.
General Guidelines
• The pH should be controlled from 8.0 to 9.0.
• All solids control equipment should be run while drilling cement. Sodium bicarbonate will
aid in lowering the pH and will precipitate soluble calcium. Pre-treat the active fluid
system with 1 ppb of Sodium bicarbonate before drilling cement.
• High viscosity sweeps will be used throughout the operation. These sweeps should have a
yield point greater than 50. All sweeps should be at least 100 barrels to increase their
effectiveness.
• Wiper trips are an important tool in gauging hole conditions. A wiper trip at least every 500 ft
can detect a build-up of pressure identified by swabbing.
• Packing fraction refers to that state when a fluid begins to exhibit semi-plastic tendencies due
to solids. For example, the packing fraction of bentonite in freshwater is approximately 5%
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 6-24