Transcript RIG PROCESSES

RIG PROCESSES
 Drilling, Coring, Directional
Drilling & Survey.
 Tripping, Wash & Ream, Fishing.
 E- Logging.
 Casing & Cementing.
 Perforating &Testing.
 Acidizing & Fracturing.
Drilling & Coring
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Normal Drilling.
Coring; Convetional Coring:
Core head
core barrel
Tripping
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((Pulling out or running the string in hole ))
Normal tripping.
Tight Hole.
Wash and Ream.
Normal Drag.
Overpull.
Twist off.
Stuck
Fishing
II. Stuck pipe
Drilling string
cannot be raised,
lowered or rotate.
Mechanisms of stuck pipe
 Differential Stuck.
 Wellbore Geometry.
 Hole packing off.
A. Differential Stuck
Sticking of pipe against a permeable
formation as the result of the pressure of
the mud in the hole exceeding the bore
fluid pressure.
Differential sticking
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Stuck breadth = 4”
Stuck length = 25’
Fm pressure = 4000 psi
H pressure = 5000 psi
D. F=4*25*12*(5000-4000)
1,200,000lbs
Key Seat
Causes:
 Abrupt change in
angle or direction in
soft formations.
 High string tension
and pipe rotation
wears a slot into the
formation.
 While POOH the drill
collars jam into the
slot.
C. Packing Off & Bridging
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Formation cuttings cavings or medium to large
pieces of hard formation, cement or junk settle
around the drill string and pack off/bridging the
annulus.
Settled cuttings
Shale instability +
Unconsolidated formations
Fractured formations
Cement related.
Junk.
Settled Cutting Straight Hole
Causes:
• Low annular velocity
and/or poor mud
properties.
• When circulation is
stopped, the
cuttings fall back
down the hole and
pack off the drill
string.
Settled Cutting Deviated Hole
Causes:
• Drill cuttings settle on
the low side forming a
cutting bed.
• The cutting bed builds
and slide down hole.
• While POOH the
cuttings is dragged
upward by the BHA
ELECTRIC LOGGING
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Logging While Drilling (MWD).
Post Drilling E- Logging.
Gamma
Resistivity
Neutron Density.
Sonic.
Resistivity
Sonic
1000
1500
1500
2000
2000
TVD (m)
TVD (m)
1000
2500
re s pons e
in cas ing
Cycle
Sk ipping
Top of
Ove rpre s s ure
2500
Top
Ove rpre s s ure
3000
3000
NCT
NCT
3500
3500
0.1
1
RILD (ohm.m)
10
100
Sonic (usec/m)
1000
CASING
Casing is steel pipe
placed in an oil or gas
well at the end of
every drilled phase,
and then cemented in
place prior to striating
drilling the lower
smaller hole section.
Function Of Casing
 Printing hole from caving or collapsing
 Privinting loss of drilling fluids into weak
formations.
 Isolate troublesome formations.
 Prevent communication between
formations.
 Provides means of extracting
hydrocarbons
 Provides a means of support for the
wellhead equipment.
Casing Accessories
Centralizers: attached to the casing and
since they have a bowed spring
arrangement keep the casing centred in
the hole after it is lowered in. Centralised
casing can make for a better cement job
later.
Scratchers
Float collars
Cementing
Well Completion
– Completing the well & Setting Production
Casing.
– Perforating production casing.
– Drill Stem Test (DST).
– Acidizing.
– Fracturing.
– Installing the Christmas Tree.
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