BAKER HUGHES - Drilling Fluids Reference Manual

Water Based Drilling Fluids
Table 3-25
AQUA-DRILL Applications in the North Sea
Well Name 21/25-10 29/3a-5 21/25-12 30/16-13 211/29-BD-
46
Product Concentrations
29/7-5
KCl, lbm/bbl 35.00 37.60 39.58 35.52 33.83 39.19
MIL-PAC REG, lbm/bbl 1.26 0.87 1.07 0.58 1.03 0.57
MIL-PAC LV, lbm/bbl 2.10 2.01 3.91 1.00 1.10 2.01
NEW-DRILL L, lbm/bbl 2.10 1.99 1.78 1.17 1.65 2.42
XAN-PLEX D, lbm/bbl 0.56 0.31 0.47 0.49 0.80 0.60
AQUA-COL M, % by vol 3.00 3.40 3.94 3.10 3.11 3.73
CAUSTIC SODA, lbm/bbl 0.49 0.94 0.57 0.80 0.79
MIL-BAR, lbm/bbl 267.00 223.90 283.30 141.89 120.00 232.30
Typical Drilling Fluid Properties
Fluid Weight, ppg 13.1 12.5 - 13.2 13.1 11.4 9.8 - 11.1 12.5 - 13.3
Plastic Viscosity, cP 25 - 30 30 -35 25 - 35 20 - 25 18 - 25 34
Yield Point, lbs/100 ft 2 25 - 30 25 - 30 28 - 32 20 - 27 20 - 34 36
Gel Strength, lbs/100 ft 2 3-4 / 4-8 4-7 / 5-14 3-5 / 7-8 4-5 / 6-9 6 / 12 7 / 12
MBT, lbm/bbl 5 - 15 5 - 22.5 5 - 15 5 - 11.5 5 - 20 5 - 12
KCl, lbm/bbl 25 - 35 33 - 36 25 - 35 30 - 35 35 33
Chlorides, g/L 45 - 55 45 - 57 35 - 45 40 - 46 55 50
API Filtrate, cc 4.0 - 6.0 3.0 - 5.6 4.0 - 4.8 5.0 - 6.4 5.0 5.0 - 6.0
Pf / Mf, cc 0.2 - 0.6 0.2 / 0.6 0.4 / 1.2 0.2 / 0.4 0.3 / 1.0 0.05 / 0.15
pH 9.0 - 9.5 9.0 - 9.5 9.5 9.5 - 10.0 9.5 - 10.0 9.5
Volume Built and Dilution Rate
Dilution Rate, bbl/ft 0.45 0.78 0.52 0.60 1.05 0.42
Total Volume Built, bbl 4022 7535 5063 3450 6809 4652
Hole Stability
All six wells showed good hole stability with logs, casing run, and cementing on all wells without
incident. Trips off bottom in new hole were characterized by minor tight hole due to gauge
conditions. To avoid delays, the new hole sections were pumped out using the top drive.
Further indications of the inhibition of the fluid system were the low dilution rates and minimal
increase in MBT. There may be further cost savings on future wells if fluids are run with less
dilution allowing MBT's to reach levels in the range 20 to 25 lbm/bbl. No dumping of whole fluid
is expected to be a characteristic of future wells. On Well #29/7-5, the only additional fluid built
was that to replace fluid lost on cuttings discharged over the shaker.
Chemical Discharge
Routine procedures are in place to measure the amount of oil fluid discharged with cuttings.
Similar measures to record total water-base discharges are now in place. The use of AQUA-
DRILL has resulted in dramatic reduction in the levels of chemical discharge. The typical
offshore discharge figures for water-base fluid systems are shown below
Reference Manual
Baker Hughes Drilling Fluids
3-86 Revised 2006