BAKER HUGHES - Drilling Fluids Reference Manual

Water Based Drilling Fluids
Table 3-22
Hole Size
Recommended Ranges for Gel Strengths and Yield Points for AQUA-COL
Systems
Yield Point lbs/100
sq ft
Initial Gel lbs/100
sq ft
10 Min Gel
lbs/100 sq ft
17½" / 16" 25 - 40 5 - 10 9 - 20
12¼" 18 - 25 4 - 8 7 - 15
8 3/8" / 8" 10 - 15 4 - 8 7 - 15
High and low viscosity sweeps will give further assistance in hole cleaning. In an ideal consistent
drilling situation, occasional sweeps will serve as an indication of successful hole cleaning. A
minimum initial gel strength of 4 lb/100 ft 2 will be required to ensure that there is no barite
settling on surface.
Test Procedures
In addition to the basic fluid tests of density, rheological, and filtration properties, tests for excess
NEW-DRILL, PHPA and AQUA-COL should be carried out. Two tests for AQUA-COL are
available.
Colorimetric Method (GLY-KIT)
This is the standard method for the determination of glycols in drilling fluid filtrates. The glycol
is extracted into dichloromethane using a blue complexing agent. The resulting blue color of the
dichloromethane is compared to standard solutions and the concentration determined.
Equipment
Procedure
• Eppendorf Model 3190 Fixed Volume Pipette, 100 μL
• Pipette tips, 10 to 100 μL range
• Test Solution Vials
• Color Wheel for viewing samples and holding vials
• Box of Kemwipes.
1. Obtain 1 or more ml of filtrate.
2. Attach pipette tip to pipette.
• Press the yellow control knob down to the first stop.
• Hold the pipette vertically and immerse tip about 3 mm into the filtrate.
• Let the yellow control knob rise slowly to fill the tip with liquid.
• Slide the tip out of the filtrate along the wall of the container.
• Wipe off any droplets on the outside of the tip with a Kemwipe.
3. Open the test vial and dispense the filtrate.
• Hole the pipette tip at an angle against the inside of the vial.
• Press the yellow control knob slowly down to the first stop and wait about three
seconds.
Reference Manual
Baker Hughes Drilling Fluids
3-80 Revised 2006