BAKER HUGHES - Drilling Fluids Reference Manual

CORROSION
Factors
Coupon Dimensions
Series Ring Size mils/yr Series Ring Size mils/yr Series
F
H
K
N
P
3½" E.H.
3½" I.F.
4" F.H.
4" I.F.
4" E.F.
4½" F.H.
4½" E.H.
4½" I.F.
280
252
207
195
193
F
H
203
192
189
3½" E.H.
3½" I.F.
4" F.H.
Same as 4½" E.H.
Same as 3½" I.F
2 15 / 16 "
3 5 / 16 "
3 13 / 16 "
280
252
3½"
3 13 / 16 "
4 3 / 16 "
R 5" F.H. 219 215 3 17 / 32 " 4 1 / 32 "
5" E.H Same as 4½" I.F.
V 5½" F.H. 188 184 4 1 / 32 " 4 5 / 8 "
5½" E.H. Same as 5" I.F.
X 5½" I.F. 148 145 4 7 / 8 " 5 l9 / 64 "
6" E.H. Same as 5½" I.F
Table 8- 2 Ring Factors and Formulas (for all metal rings)
F
H
7 / 16 "
7 / 16 "
7 / 16 "
5 / 16 "
11 / 32 "
7 / 16 "
Ring Placement and Scheduling
Placement – Corrosion coupons (rings) are normally placed in the crossover sub above the drill
collars, and/or in the kelly saver sub, or fluid saver sub above the TIW valve.
Scheduling – Ring coupons should be run in the drillstring for a minimum of 40 hours. In every
instance, the time must be reported as accurately as possible, even if the coupon is left in the string
for several days.
Handling of Corrosion Rings
1. Leave the ring in the shipping envelope until immediately prior to placement in the
drillstring. DO NOT HANDLE THE RING PRIOR TO RUNNING IT.
2. Wipe the recessed area inside the box end of the tool joint clean of excess fluid and pipe
dope.
3. Carefully place the ring down into the recess with the beveled side down. Care should be
taken to be sure that the ring lays flat within the recess, to avoid mechanical damage when
the joint is made up.
4. Record on the shipping envelope the location of the ring coupon and the date and time of
placement in the string. Run the ring coupon in the drillstring for a minimum of 40 hours,
but not more than 120 hours.
5. If the string is out of the hole for an extended time, remove the ring coupon and replace it
with a new corrosion ring coupon when trip-back in the hole in begins.
BAKER HUGHES DRILLING FLUIDS
REVISION 2006 8-9
REFERENCE MANUAL