STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

700 Drilling and Well Completions
Table 4-58
(continued)
Problem Symptoms Treatment
to porous formations
A very rapid seepage loss
to permeable sandstones Gradual seepage loss
to cavernous formations
to fractured formations
5. Pipe stuck
Differential sticking
Key-seat
Undergauge hole
Particles in the hole
6. Hole instability
7. Corrosion
in water base muds
Immediate and complete
loss
Sudden but not total loss of
fluid. It occurs often after
trips (induced fractures)
when heavy mud is in
use. The loss zone is
frequently below the
deepest casing shoe.
The drilling string got stuck
after remaining motionless
in the hole circulation can
be broken and continued
at normal pressure.
Permeable formation is
exposed above the bit.
The borehole is clean and in
good condition.
see “Diagnosis of stuck
pipe”
as above
as above
While drilling: tourgue, drag,
difficulty with making
connections, bridging, fill
on bottom, stuck pipe,
presence of slaughing
material in cuttings. After
drilling: caliper log shows
caving.
Internal and external pitting
“Gunk” squeeze or a high
filtration squeeze
1. Increase colloidal content
of mud
2. Add granular or flake LCM
If the loss zone is locate+
a “sofl plug” to be spotted.
“Blind drilling (no returns);
then set casing or cement.
Apply cement squeeze or
attapulgite gel-barite
squeeze.
1. Try spotting fluids
2. Wash over
Control mud weight to
counter balance pore
pressure. Keep fluid loss
as low as possible. Keep
viscosity and gel strength
low to prevent swabbing.
Convert to: 1) salt-polymer
mud, or 2) potassium
system, or 3) salinity
controlled oil mud.
1. Keep pH above 10.
2. Use cationic type
inhibition. 3. Identify type
of corrosion. 4. Add
specific corrosion
inhibition.