TEP/DEG/CEF/SUB . . . Natters Around Field . . . October 1998 MUDLOGGING MUDLOGGING ... for dummies CONTENTS TOOLBOX module 6.1 s GENERALITIES: PAST & FUTURE PRESENTATION s SUMMARY s Introduction: AIMS & PURPOSES s SENSORS, DATUM & DATA s GAS: DEFINITION, ORIGIN, MEASUREMENTS, INTERPRETATION s PRESSURE: GENERALITIES: Hydrost., Overburden , Pore Pressure FORMATION: S OBG , ’d’exp, ... WELL MEASUREMENTS: LOT, FIT, SBT, Csg Test s SAMPLING: PROCESSING and DESCRIPTION s LABORATORY: PREPARATION and ANALYSIS s CORING: EQUIPMENTS and OPERATIVE TECHNICS s REPORTING: DGR, GWR and DDR s ANNEXES s CONCLUSION
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TEP/DEG/CEF/SUB. . . Natters Around Field . . .
October 1998
MUDLOGGINGMUDLOGGING ... for dummiesCONTENTS
TOOLBOX
module 6.1
s GENERALITIES: PAST & FUTURE PRESENTATION
s SUMMARYs Introduction: AIMS & PURPOSESs SENSORS, DATUM & DATAs GAS: DEFINITION, ORIGIN,
MEASUREMENTS, INTERPRETATION
s PRESSURE: GENERALITIES: Hydrost., Overburden, Pore Pressure
FORMATION: SOBG, ’d’exp, ...WELL MEASUREMENTS: LOT, FIT, SBT, Csg Test
s SAMPLING: PROCESSING and DESCRIPTION
s LABORATORY: PREPARATION and ANALYSIS
s CORING: EQUIPMENTS and OPERATIVE TECHNICS
s REPORTING: DGR, GWR and DDR
s ANNEXESs CONCLUSION
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
GENERAL PRESENTATION
S U M M A R Y
MUDLOGGING: «on the road again ...»from ... STONE AGE BIBLESto ... 21st century BIBLES => TOOLBOX module 6.1)THEMATIC RESEARCHALPHABETIC RESEARCHTECHNICAL DATA SHEETS: examples (Toolbox module 5.2)GEOLOGICAL WELL REPORT (Toolbox module 7.0)MUDLOGGING AUDIT (Toolbox module 2.1)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
TESTING
CIRCULATING FISHING
CORINGLOGGING
DRILLINGD R
I L L
I N G
R
E G
U L
A T
I O N
S
DATAENGINEER
MUDLOGGER
SAMPLECATCHER
WELLSITEGEOLOGIST
DATA ACQUISITION
EVALUATING
DRILLING EVENTS
MUD PARAMETERS
LITHOLOGICAL & GAS DATA
HT
DATA MANAGEMENT
WELL FOLLOW-UP
REPORTING PREPARINGRECORDING
WELL MONITORING
DATA DISPATCHINGINTERPRETATION
DATADISPATCHING
D R I L L I N G P R O P O S A L
LOTFITHP
GWR
S A
F E
T Y
R
E G U
L A
T I O
N S
M U D L O G G I N G
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
’STONE AGE’ BIBLES ...
USEFUL, BUT:- DIFFICULT TO MANAGE (heavy, huge, ...)- BORING RESEARCH & READING
Md iu L ngo g
g
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
... 21st century BIBLES
FILES:- STRICKLY A4 SIZE- MAINLY VISUAL- ESSENTIAL TEXT- FAST CONSULTATION- EASY TO UPDATE
THEMATIC RESEARCHALPHABETIC RESEARCHLINKAGE between FILES
WEB siteINTRANETM
UD L O G
I NG
G
SENSORS
GAS
PRESSURE
LABO
RATO
RY
SAMPLINGCORING
RE
PO
RT
ING
ANNEXES
CDWSG AIMS ...
THE TRICKS OF THE TRADE
TOOLBOXmodule 6.1
… JOB PURPOSES
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
THEMATIC RESEARCH
INTRODUCTION: AIMS
CORING
DATUM, SENSORS & DATA
SAMPLING
ANNEXES
GAS
PRESSURE
LABORATORY
REPORTING
KEYWORDS INDEX RESEARCH
CONVERSIONS & EQUIVALENTS
UNIT CONVERTER
BASIC WELLSITE GLOSSARY
International SPELLING CODE
. . .
TOOLBOX - module 6.1
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
Mudlogging KEYWORDS index research
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
EASY RESEARCH … Press to
BASICGLOSSARY
(GB - F - E)
KEYWORDGENERAL INDEX
OIL FIELDABBREVIATIONS
TECHNICALDATA SHEETS
UNITCONVERTER
More … ?
OPEN
CUTTINGDESCRIPTION
SHEET
MUDLOGGINGAUDIT
GEOLOGICALWELL REPORT
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
TECHNICAL DATA SHEETS
Geoservices
DRILLING SENSORS
TECHNICAL DATA SHEETS
sensor type & model
DRAWWORKS
MEASUREð Aim: To measure the rotation of the Drawworks drum and so the hook
movement.
� Features & Benefits:n Can easily be rigged up, does not normally require maintenance.n True real-time measurement.n Pipe velocity is actually calculated allowing real surge and swab calculations.
� Principle: A notched wheel with teeth rotates with the cable drum and twoproximity sensors detect the movement of the wheel which send pulses to the ALSsystem. The pulses are computed in hook movement knowing initial characteristics ofthe drum and the line.
� Manufacturer: Turck � Unit: Si 3.5 K 10 Y0
� Certification: EEx ia IIC T6
CHARACTERISTICS� Type of Output: Pulses. 3 to 8 V � Range: 48 pulses/turn
� Sensitivity: 1/48th of the DRW drum revolution. � Alarm: YES (HI/LOW)
� Accuracy: +/- 1cm � Repeatability: +/- 1 pulse
� Dimens.: N/A � Weight: N/A
MAINTENANCE� Calibration & frequency: By physical comparison of actual vertical movement of
the travelling block.
� Check & frequency:n Check of the agreement with the Driller’s depth with the pipe tally.n During each trip or every 5 days: physical inspection of the sensor.n Recalibrate each time the cable is changed.
OPERATING MODE� Power: � Voltage: 8V DC
� Sensor location: On the shaft of the drawworks.
� Operating limits: -25 -> +70 °C
CONTRACTOR Reference :-TOTAL Experience :-
Geoservices
MUD SENSORS
TECHNICAL DATA SHEETS
sensor type & model
PIT LEVELULTRASONIC
MEASUREð Aim: To measure the mud level in the pits and to know the pit volumes.
� Features & Benefits:n Light and compact.n Accurate, intrinsically safe.
� Principle: The sensor emits an ultrasonic wave which is reflected at the surface ofthe fluid. An accurate measurement of the time taken to the wave to return gives thedistance to the level of mud.
� Manufacturer: Milltronics � Unit: «The Probe»
� Certification: EEx ia IIC T4
CHARACTERISTICS� Type of Output: Analogic. 4 - 20 mA � Range: 0.3 - 5 m
� Sensitivity: 3 mm � Alarm: YES (HI/LOW)
� Accuracy: +/- 5% of Full Scale � Repeatability:
� Dimens.: N/A � Weight: 1.5 kg
MAINTENANCE� Calibration & frequency: With a tape measurer.
� Check & frequency:n Once per shift: check levels of pits, clean sensor if necessary.
OPERATING MODE� Power: � Voltage: 12 to 30 V DC
� Sensor location: Over the pit, at least 0.3m over the maximum mud level.
� Operating limits: -40 -> + 60 °C
CONTRACTOR Reference :--TOTAL Experience :--
Geoservices
GAS EQUIPMENTS
TECHNICAL DATA SHEETS
equipment & model
GZGDEGASSER
for GASLOGGERand
for RESERVAL
MEASUREð Aim: To extract gases from mud at a constant rate with equal performances on
light and heavy gases.
� Features & Benefits:n Independant of mud level variations in the mud return circuit.n High efficiency of degassing and constant performances quite independant of mud
parameters (density, viscosity, solids content,etc).n Good extraction of gases from the mud (85%) with equal performances on heavy
and light gases.
� Principle: The mud is pumped into a degasser tank where an agitator extracts thehydrocarbon gas.
� Manufacturer: Geoservices � Unit: GZG
CHARACTERISTICS� Type of Output: N/A � Range: N/A� Sensitivity: N/A � Alarm: NO� Accuracy: N/A � Repeatability: N/A
� Dimens.: 79x57x24 cm. � Weight: 38 kg
MAINTENANCE� Calibration & frequency: No calibration.
� Check & frequency:n Several time per shift: check for steady mud flow from outlet.n Once per shift: Check gas line air tightness.n Every 5 days: Check gas transit time, lubricate pump diaphragm, inspect screen
assembly and blade for wear.
OPERATING MODE� Power: 120/140 W � Voltage: 220/380 V AC
� Purpose 1: Gas Out ð location: Flow Line.� Purpose 2: Gas In ð location: Suction pit.
MEASUREð Aim: To measure and record the amount of carbonates contained in rock
samples and quantify Calcite and Dolomite.
� Features & Benefits:n Compensation of sample weight between 0.90 and 1.10 g.n Memory capacity up to 800 calcimetries.
� Principle: A corrosive attack of a known amount of rock using hydrochloric acid,some carbon dioxide is produced. A sensor records the pressure increase and amicroprocesseur calculates the percentage of carbonates contained in rock samples.
� Manufacturer: � Unit:
� Certification:
CHARACTERISTICS
� Type of Output: � Range: 0-100%
� Sensitivity: 0.1 % � Alarm: NO
� Accuracy: 1 % � Repeatibility:
� Dimens.: 240x270x300 mm � Weight: 11 kg
MAINTENANCE� Calibration frequency: With pure CaCO3 as reference.
� Check & frequency: Every 5 days and before a new section check the calibrationand adjust if necessary.
. long cycle => (short cycle) + (transit time on surface: from return pit to succion pit)
. LAG CHECKS, to be performed during pipe connection (short cycle): . Calcium Carbide lag (CaC2) => Acetylene peak (C2H2) on chromato. (WBM mud only) . Crushed brick lag => First arrival easily seen on Shakers screen (reddish grained) . Rice lag => Not expensive, but not easy to check on Shakers (milky-whitish-light tan) . Eventually Mica => in case of LWD (warning: possible effect on WL response)
L a g T im e A n n u lar Vo lum eF l o w R a t e
m in= ⇒
Lag Stroke Annular VolumeStroke vol eff
stroke nb= ⇒( ) * (Pump .)
with AV = (OH vol + IDCSG vol) - (OD IRON vol in hole) FR = (Stroke vol) * (Pump efficiency %) * (SPM)
Cuttings arrive «early» regarding to ROPTight Hole
=> STICKY HOLEShale hydration (Monmorillonite)
in both casesDRILLING PROBLEMS
INVIEW ... as delta P
=> Carefully check lithologyon all sieves
BUT, IT MAY ALSO BE DUE TO:- Wrong Pump efficiency (Toolpusher data) and/or false adjustment (Data Engineer)- Incomplete or erroneous pipes dimensions (OD & ID) and volumes, ...
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
DRILLING SENSORS SENSORS
WOH Weight On Hook ................................... Dead line or Hook Load=> WOB Weight On Bit computed from Archimees law
(or buoyancy effect)
SPP Stand Pipe Pressure ....................... Stand pipe Manifold
CP Casing Pressure ..................................... Diverter Manifold and WHP Well Head Pressure
ROP Rate Of Penetration & Depth ... Drawwork axleHKPos Hook Position / Travelling Block
RPM Revolution or ........................................... Rotary Table Rotation Per Minute or Top Drive
SPM Strokes Per Minute .................................... Pump piston
PRESSURE TRANSDUCERSmeasuring strainon force triangle
(klbs or tons)
measuring variationsof steel diaphragm
(psi or bars)measuring capacitanceof detecting diaphragm
(psi or bar)
PROXIMITY SWITCHmeasuring crown sensor
counter(logic condition: 0 or 1)
HYDRAULIC
ELECTRIC
Hydraulic system
TRQ Torque ................rotary table (RT)
Electrical lineCURRENT TRANSDUCER
HALL effect: measuring electrical fieldflowing in motor cable (Amp)
items mounting on
MEASUREMENT
method principle
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
MUD SENSORS SENSORS
Flow Rate .......................................................flow line
Potentiometer (floater)
Potentiometer (paddle)
Platinium resistance
HYDRAULIC
ELECTRIC
items mounting on
MEASUREMENT
method principle
Echo pulse (ultrasonic) ACOUSTIC above mud tank
PITS Volume ..............................
in mud tank
IN ........suction pitTEMP° ................................... OUT .......possum belly
IN ........suction pitCOND. / RESIST................... OUT .......possum belly
Toroidal induction coil
Differential pressure
Gamma ray absorption (NUCLEAR)
IN ........suction pit
OUT .....gas trapMud Weight / DENSITY..... IN ....... stand pipe OUT .......possum belly
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SENSORS MEASUREMENT & SPECIFICATIONP
R I
N C
I P
L E
WOH / WOBSPP
CP / WHPTRQ (diaphragm)
DENS. / MWTRQ (Hall effect)
PITS Volume(ultrasonic)
(DENS. / MW )
MUD &DRILLINGsensors
HYDRAULIC ELECTRIC ACOUSTIC NUCLEARM E T H O D
RADIOACTIVE
RESISTIVITY
Pressure
CurrentTRANSDUCER
T
10PROXIMITY switch
(counter)
POTENTIOMETER
ULTRASONIC
ROP / DepthHKPos
RPMSPM
COND. / RESIST.TEMP°
PITS Vol. (floaters)FR (paddle)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
G A S : DEFINITION & MEASUREMENT S U M M A R Y (1/2)DEFINITION
- GAS SAMPLING HISTORY- GAS TYPES RECORDED- GAS SHOWS: Definition
Origin … or sourcesSwab & SurgeGas Events vs … warning!Main ranges
- MUD DEGASSING ON SURFACE
MEASUREMENT- GAS MEASUREMENT CHAIN- DEGASSER TYPES- GAS LINES:efficiency
main & back-up- DETECTOR:principles- DETECTORS for ACID GASES- H2S: HYDROGEN SULPHIDE => the Killer gas- CHROMATOGRAPHY: problems to solve
principles & efficiency- FID: total gas & chromatography- TCD: total gas & chromatography
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
G A S : INTERPRETATION
S U M M A R Y (2/2)
INTERPRETATION
- LOG/LOG DIAGRAM (SNPA)
- PIXLER PLOT (BAROID)
- TRIANGLE METHOD (GEOSERVICES)
- Wh, Bh, Ch RATIOS (EXLOG)
- LIGHT HYDROCARBON RATIOS: interpretation
- RATIOS ACCURACY
- GAS NORMALISATION: AIM
- GAS NORMALISATION: magic! or bluff?
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
GAS Sampling: HISTORY
< 1930’s > 1930’s (1980’s) -> PRESENT FUTURE
«rule of thumb method»
Based on . shows estimation . depth levels uncertainty
gas ratios used: C1/C2 C1/C3 C1/(iC4+nC4) C1/(iC5+nC5)
=> LINES ARE DRAWN BY CONNECTING INDIVIDUAL RATIOS
Comments:- Plot basically based on C1/C2 ratio (see ratios accuracy)- Steep slopes are usually a «tight reservoir» criteria- Negative slope might be a «water zone»
Texas and Louisiana experiences
Non-productive Gas
Productive Gas
Non-productive Oil
Productive Oil
(wet gas)
(dry gas)
(volatile oil)
(heavy oil)
(tars, bitumen)
(no free gas)
C1/C2 C1/C3 C1/C4+ C1/C5+
… based on productiongas data (DST)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
TRIANGLE METHOD (Geoservices)
so-called «POTATO PLOT» (early 1970’s)
developed in Middle-East, extended to Europe & Africa
2 - HOMOTHETIC CENTER defines PRODUCTIVE ZONES:by drawing 3 lines from «initial plot apexes (A,B,C)»
to «sample ratios apexes (a, b, c)»IF HOMOTHETIC POINT IS INSIDE «brown POTATO»
C2/C(1-5)
C 4/C
(1-5
)
C3 /C
(1-5)
A
B Cupward
«a» apex
downward
GAS
OIL
drywet
high GOR:Condensate
low GOR:Tars
a
b c
a
c b
… based on productiongas data (DST)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
Wh, Bh and Ch ratios (EXLOG)EXLOG (1985), now BHI
gas ratios used … based on drilling:
1 - WETNESS
2 - BALANCE
3 - CHARACTER
W h C C C CC C C C C
= + + ++ + + +
( )( )
*2 3 4 5
1 2 3 4 51 0 0
B hC C
C C C= +
+ +( )
( )1 2
3 4 5
C h C CC
= +( )4 5
3
(*) N/A => incompatible
Wh < 0.5 0.5 - 17.5 17.5 - 40 > 40
Fluid DRY GAS GAS OIL Residual Oil
Bh Fluid
> 100 dry Gas
> Wh GAS
Bh Fluid
>>Wh coal bed
> Wh GAS
= Wh lt G / Cond
Bh Fluid
> Wh coal-N/A*
< Wh OIL
<<Wh heavy OIL
Bh Fluid
> Wh N/A*
heavy to<< Wh residual OIL
1001 10 0 1 2 3
VERY LIGHTDRY GAS
LIGHT GAS
GAS &LIGHT OIL
COAL-BEDEFFECT
MEDIUMGRAVITY OIL
RESIDUALOIL
Wh ratio
Bh ratioCh ratio
0.54017.5
< 0.5 GAS or COAL COAL or N/A* Ch > 0.5 N/A* OIL
CONT
INUO
US PL
OTTIN
G
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
LIGHT HYDROCARBONS ratios INTERPRETATION
1001 10 0 1 2 3VERY LIGHT
DRY GAS
LIGHT GAS
GAS &LIGHT OIL
COAL-BEDEFFECT
MEDIUMGRAVITY OIL
RESIDUALOIL
Wh ratioBh ratio
Ch ratio
Non-productive Gas
Productive Gas
Non-productive Oil
Productive Oil
1 10 100 1000 10000 1000001
10
100
1000
10000
100000
(C2/C1)x103
(C3/C1)x103
C2/C(1-5)
C 4/C
(1-5
)
C3 /C
(1-5)
WHICH PLOTto trust ?
NONE or ALL !
NO MIRACLE METHOD
WHY ?
... based onRATIOS ACCURACY
CALIBRATED IN SPECIFIC AREAS
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
RATIOS ACCURACYDEPEND ON . . .
- Fluids pre-identification & characteristics - Detection & Monitoring HP wells- Geosteering (warning: recycling?) and ... GAS DATA RELIABILITY!
SELECTED GAS RATIOS REMAIN HIGHLY HELPFUL for:
NEVER FORGET «ROP vs Cycle time analysis vs Reservoir thickness»
DEGASSER: location efficiency?
GAS LINE: Flow pressure pre-elution? Ambiant Temp° (Atmosph. Press.) DETECTORS: «windows» calibration? ... for each component sensitivity? thus, better use «C1+C2» overlap? (instead of «C2/C1» or «C1/C2» ratios)
... GAS MEASUREMENT CHAIN
Rate Of Penetration Drilling modes (rotary, sliding) Mud Flow Rate Bit types Mud weight Mud type (WBM, OBM, ...)
Help for GAS NORMALISATION
... DRILLING PARAMETERS
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
GAS NORMALISATION: AIM
It normally ONLY represents the LIBERATED GAS content per volume of rock drilled warning IF: GAS RECYCLED (from surace) IF: GAS CONTAMINATION ( from mud, bit, ...) => BACKGROUND GAS
IF: GAS PRODUCED ( from Open Hole)
SEVERE LIMITATIONS: sources of gas, Temperature & Pressure effectson mud gas composition while gas migration , ...
CGI
VGN
SPI
CGS
Corrected Gas Index
Volumetric Gas Normalisation
Surface Potential Index
Calculated Gas Saturation
attempts forGAS
NORMALISATION
A I M :TO ELIMINATE CHANGES IN DRILLING PARAMETERS AND IN MEASURING CONDITIONS BASED ON TOTAL GAS Measurement (TG)
WHOLE CRITERIA MAY or MAY NOT REACTand IF ONLY 1 => ALERT
(diversity)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
Swab Gas Test & Long Connection Test
AIM ANTICIPATE the ARRIVAL OF the TRANSITION ZONE with the lowest MW
PC
PC
1 std (Top Drive)1 single (Kelly)
time
Hook height
SPMSwGT• Stop drilling• Stop circulating• ‘Off Bottom’ 3-5mswabbing time < 1min• Resume circulation• Back to drillingTotal DURATION: 5-10min
PSWB << PFORM < PECD
PC
PCtime
Hook height
SPM LCT• Stop drilling• ‘Off Bottom’ 2-3m• Circulating ~10min• Stop circulating LCT time ~10min• Resume circul’ ~5min• Back to drillingTotal DURATION <30min
PLCT < PFORM < PECD
Better ’PFORM ’ follow-up with LCT than SwGT (PSWAB < PLCT)PROCEDURE
Mudlogging crew records gas on surface(and checks associated lithology),
then informs WSG and Co-Man for actions:
• Keep on drilling … to next gas test• Increase MW step by step (5 points= 0.05sg)• Logging & Set casing (depending on LOT, FIT)
FormGBKG
SwG
TG laggedFormG
BKG
LCT
TG lagged
SwG
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
z
DRILLING PRESSURE EVOLUTIONDE
PTH
PRESSURE (EMW)
OVERBURDENFRACMW
Hydrostatic Press.
PP ECD
2
3
43
5 5
1too early (?) for- setting Casing- rising MW(possible LOSSES)
too late (?) forrising MW => KICK(if porous reservoir)
PP = MW, but still < ECDUnsafe drilling … => well in equilibrium (in static conditions)
ECD > PFRAC ( or ≥ PLOT)=> LOSSES(slow pump rate: reduce ECD and pump LCM)
2
1
4• drilling conditions => LOSSES (ECD > PFRAC)• static conditions (PP > MW) => GAIN to KICK… depending on permeability
THE WORST SITUATION!
What to do?
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
’ROP’ NORMALIZED … STORY!
• BINGHAM (1964, Gulf coast): relationships between LITHOLOGY and DRILLING PARAMETERS
’d’ exponent empirical formula
=
BS inches
WOB lbsK
RPMROP hrft
)(
)(.)/(
BSWOBRPM
ROP
inches
lbs
*
hrft
d
* )(
* )(
10
)/(
10
6
''
1012log60log
=
• JORDEN & SHIRLEY (1966) solved this equation for a constant lithology (K=1 for shale)
with d = compaction exponent (=> ‘ d ’ exp) and K = lithological constant
Any decrease in ‘ d ’ exp(expressed in EMW)
when drilling a shaly sequenceis a function of the degree
of undercompaction
• REHM & McCLENDON (1971): ‘ d ’ exp corrected for mud weight (∆P function of Shale pore presure)
ECDPhydro
EMW
EMWddc)(
)('.''' =Parameters not taken into account:
- ∆P, not known accurately - bit type and bit wear- mud hydraulics when drilling with jetting (unconsolidated Clay)
Why only forSHALE?
)*(exp*@ ZCstsurfacedepthCLAY Z −=φφ
RUBEY & HUBBERT law (1959)
φ
Ζ
CLST
SST
easy,Man?
Yeah!
Fair enough?NO !
d
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
UPGRADED or ADVANCED ’d ’ exp
How to restitute an almost true normalized ROP ?
)(
)(
)(
)(
)(min/ **026469.0
log
**3048.0log
EMW
EMW
inches
T
m
p
c ECDPhRPMc
BSWOB
ROPa
d =corrected for ROCK BITS
as new onesfor each depth drilled
)(*
8
1*3*31.0
18
*38
*31.0
)(?0.0)(2.01.0)(5.03.01*6*93.0
)09.1*10*8(2
2
2
4
drilledIntervaldepthBitdepthBitBWx
and
RPMRPMandxx
BWBW
Z
with
bitPDCbitinsertbitteethpandZZa
where
INOUT
RPMcorrected
−=
=++
++=
−−=++=
+− −
WELLSITE GEOLOGIST& MUDLOGGING Crew
MUDLOGGING UnitCOMPUTER
dCndCo
YES!
HELP!
è … and ‘dCn’ still not drawn !
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
NORMAL COMPACTION TREND ’dCn’• RUBEY & HUBBERT ⇒ log(φ ) = -c.Z + log(φo) => linear relationship between Depth (Z) and Porosity (φ )
• ZAMORA: the ‘ d ’exp (proportional to porosity), follows the same law for claystone/shale:
Slope A( )
12
12 /logDepthDepth
ddA CnCn
−= [ ]DepthAdCn
Cn
B
DepthAdB*)log(10
*)log()log(−=⇒−=
Intercept B
Example:@ 1500m dCn= 1
@ 4500m dCn= 2
slope A= 1.003*10-4
intercept B= 0.707Computer job(MUDLOGGING CREW)
Geologist job
log(dCn) = A.(DEPTHTVDBRT) + B
0
1000
2000
3000
4000
5000
3 5 2 31.00
*
*
SLOPEINTERCEPT
dCn
dCo
dc(EMW)
Dep
th(T
VD
BR
T)
[ ])log(*10 BDepthACnd +=⇒ At any depth:
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
ROCK BIT types vs ROP curve vs ’d’ exp
Cone bitsNOZZLES3 x ??/32’’
Fixed head bitsNOZZLES or
TOTAL FLOW AREA
TEETH bit INSERT bit Polycrystalline Diamond Compact
Rock is SHATTERED by pressure Formation is CUT with cutters• ROP curve CONTRASTED: drilling parameters relatively steady• Cuttings shape & size generally well representative of rock compaction
• ROP curve SMOOTHED: parameters adjusted vs lithology • Cuttings shape & size fairly to non representative of rock compaction
NOZZLES
3 x … /32’’
TFA inch2
convertedto equiv.nozzles
+ -
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
COMPACTION TREND and Drilling param ’s
COMPACTION TRENDassumed to reflect a normalized ROP
with constant (!) DRILLING & MUD
parameters
WOBRPMBit typeBit size
OBMWBMMWECD
è ADJUST ‘END to END’ SHIFTSè WITHOUT CHANGING SLOPE(S)
Fast ROP (min/m) Slow
Depth
OBM effectWBM effectDCn
TEETHtricone bit
èPDC bit
ç Core bit
Worn bit
è
ç
çINSERTtricone bit
IT WORKS!
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
COMPACTION TREND and LITHOLOGY
è check LITHOLOGYè check CALCIMETRY
Fast ROP (min/m) Slow
DCn
Sandbaseline
DCo
SILT effect CO3 effect
Depth
Shalebaseline
Dco => OBSERVED
COMPACTION TRENDassumed to reflect a normalized ROP
based on pure (!)CLAYSTONE / SHALE
Dcn => NORMAL
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
COMPACTION TREND OBSERVED ’dCo’
’dCo’reflects a ‘Normalized ROP’
corresponding to:
normalcompaction
dCo= dCn
0
1000
2000
3000
4000
5000
3 5 2 31.00
dCn
d(EMW)
Dep
th
dCoabnormal
compactiondCo < dCn
porepore
porepore
The increase in pressure isproportional to the difference
1 - Determine the ’dCn’ trend: ( slope & intercept)
2 - Compute at each depth, knowing- the SOBG (regional or recomputed)- the Ph hydrostatic gradient (1.00 to 1.08)
the theoritical values of the ’dCo’ for different pressure gradients (1.20, 1.40, 1.60, … )
⇒ using Eaton ’s formula:
2.1*h
pnCnCo
PSPS
dd−−=
Quick look method for Shale Pp
Note: Eaton exponents may vary (1.1 - 1.5)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
’dCo’ OVERLAYS example (Excel worksheet)NORMAL TREND dcn:
log(dcn)=A*depth+B A=(log(dcn2/dcn1))/(depth2-depth1) OVERBURDEN:dcn1 = 0.75 sgEMW 0.00010557 => slope S=a*(ln(depth))^2+(b*(ln(depth))+cdcn2 = 0.9 sgEMW B=10^(log(dcn1)-A*depth1) depth in meter
depth1 = 250 m 0.70577702 => intercept a => 0.01447depth2 = 1000 m => dcn at depth: b => -0.01491
dcn=10^(A*(depth)+log(B)) c => 1.28700 Pr.hydr. = 1.01 sgEMW => OVERLAY at depth: or enter new coefficientsEATON exp'= 1.2 dco= dcn*[(S-Pp)/(S-Ph)]^(1/Eaton exp') or enter local OBG formula
SHALE PORE PRESSURE at depth: S = 2.129 SHPP= S-(S-Ph)*[dco/dcn]^1.2dco = 1.35 dcn = 1.65 => 1.249 sgEMW
Injected through formation: => 1.25 bbl = 200 liters
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CHARACTERISTIC PROFILES
Csg Test1 SBT2
CASINGSHOE
LOT3
Permeable bed
FIT4
Permeable bed
Permeable bed
SOB !
P (psi)
V (bbl) T (min)
(15 min)
VOLRECOV = VOLPUMPED
P (psi)
V (bbl) T (min)
VOLRECOV VOLPUMPED≅
P (psi)
Volume (bbl) Time (min)
FRACTUREPROPAGATION
VOLRECOV < VOLPUMPED
P (psi)
Volume (bbl) Time (min)
FRACTUREPROPAGATION
VOLRECOV<< VOLPUMPED
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
PRESSURE ANALYSES
CEMENT
RAT HOLE
CASINGSHOE
FRACTUREPROPAGATION
P (psi)
Volume (bbl) Time (min)
BA
PLOT > Ppropag.1
VOLRECOV << VOLPUMPED
P (psi)
Volume (bbl) Time (min)
AB FRACTURE
PROPAGATION
PLOT = Ppropag.2
VOLRECOV < VOLPUMPED
SBTPOOR or WEAK CEMENT JOBPOSSIBLE REMEDIAL JOB?
GOOD CEMENT JOB,SAFE in case of KICK CONTROL(CIRCULATION through CHOKES)
LOTHIGH PROPAGATION INTOre-OPENED FRACTURES,
LIMITED ‘ECD’ WHILE DRILLINGFORMATION NOT DAMMAGED
BELOW THE SHOE
+
SOB !
? ?
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
S U M M A R YSAMPLING PROCESS:
- SAMPLES: Why? and Types?- SAMPLES: Preservation ... what for?
SAMPLING: BASIC RULESCUTTING PREPARATIONWASH OUT SAMPLE EVALUATIONCUTTING PERCENTAGE ACCURACY and VISUAL ESTIMATIONDESCRIPTION and Order Standardization:
General RECOMMENDATIONS1 - ROCK NAME2 - COLOUR3 - HARDNESS / INDURATION4 - TEXTURE: General
SummarySEDIMENTARY PARTICLESCARBONATE DESCRIPTION
5 - MATRIX and CEMENT6 - FOSSILS and ACCESSORIES7 - Apparent POROSITY8 - OIL SHOWS: Generalities
ObservationComments
SAMPLE PROCESSING
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SAMPLING PROCESS (1)
AIM OBSERVATION and EVALUATION OF FORMATION DRILLED,SUMMARIZED IN MUDLOG DOCUMENT, ON RIGSITE
a- CONSTITUENT GRAINSb- MATRIX and/or CEMENTc- STAINING (mud products, iron, ... , OIL) STRESS ON PREDOMINANT COLOURSTRESS ON PREDOMINANT COLOURREDDISH to LIGHT BROWN
(rdsh-lt brn)
BROWNISH to ORANGE(brnsh-or)
TRAFFIC LIGHTSfor
COLOUR BLIND WSG
for more details, see theROCK COLOR CHART
(The Geological Society of America)representing the:
U.S. Geological Survey, AAPG, ...
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SAMPLE DESCRIPTION (5): 3 - HARDNESS / INDURATION
MOH’s scale (standard Mineral and Qualifying terms)
1 - TALC loose, uncons. lse, uncons 2 - GYPSUM friable fri 3 - CALCITE soft sft 4 - FLUORINE plastic plas 5 - APATITE firm frm 6 - ORTHOCLASE brittle (as coal) brit 7 - QUARTZ moderately hard mod hd 8 - TOPAZ hard hd 9 - CORUNDUM very hard v hd 10- DIAMOND very hard v hd
French scale
Ta your
Grosse huge
Concierge caretaker
Follement madly
Amoureuse in love
Ose dares
Quémander asking
Tes your
Caresses divine
Divines caresses
(brittle)
(very hard)(friable)
(soft)
ROP WBM OBM
ANHYDRITE v slow pasty, soft mod hd
SALT v fast «lost» firm
NAIL: 2.5
GLASS: 5.5
STEEL: 6.5
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SAMPLE DESCRIPTION (6): 4 - TEXTURE: GENERAL
ORGANISATION of the COMPONENT ELEMENTS of the ROCK
(simplified WENTWORTH scale)
SIZE ARRANGEMENT
extr wl srt
v wl srt
wl srt
mod srt
pr srt
v pr srt
mono-modal
poly-modal
ROUNDNESS:edges sharpness
v angang
sbangsbrnd
rndwl rnd
v elongelong
sli elongsli spher
spherv spher
SHAPE
SPHERICITY:shape of the grain(ratio width/length)
CLASTICS size of CARBONATESGrains element Crystals
Mud - Clay < 20µ crpXln - mXln
Silt 20 - 63µ extrXln
vf - f 63 - 250µ vfXln - fXln
med - v crs 250µ - 2mm medXln - vcrsXln
Granule-Boulder 2 - 256mm extrcrsXln
SORTING:grains range size
pr gdfr
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SAMPLE DESCRIPTION (7): 4 bis - TEXTURE summary
ROCK GRAINS / CRYSTALS ORGANISATION
SIZE SORTING
SHAPE
ROUNDNESS
SPHERICITY
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
TEXTURE: SEDIMENTARY PARTICULES
very coarse
coarse
medium
fine
very fine
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CLASSIFICATION according to DEPOSITIONAL TEXTURE
Structures of ELEMENTS
CARBONATE DESCRIPTION
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SAMPLE DESCRIPTION (8): 5 - MATRIX and/or CEMENT
M A T R I X C E M E N T
OF SMALL INDIVIDUAL GRAINS,BETWEEN LARGER GRAINS,
FILLING INTERSTICES
AROUND GRAINS or CRYSTALS,OFTEN BOUNDED TO THE SEDIMENT ,FILLING INTERSTICES and/or VOIDS
Silica, Calcite, Dolomite,Pyrite, Salt, ...
MECHANICALDEPOSIT
CHEMICALPRECIPITATE
Silt, Clay
BOTH REDUCINGPOROSITY
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
F O S S I L S A C C E S S O R I E S
EASY TO RECOGNISE, DIFFICULT TO IDENTIFYMINOR ROCK PARTICLES ARE USEFUL
FOR CORRELATIONS and FOR ENVIRONMENT INDICATORSeven if it is A SPECIALIST ’S job
=> INFORMATION on ORIGIN and HISTORY of the SEDIMENT
ARE THESE ENOUGH PURPOSESand/or REASONS TO TAKE GREAT CAREDURING & AFTER CORING ? in view of
... the GEOLOGICAL MODEL
YES,. . . almost!
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CORING EQUIPMENT
CORE BARREL(DBS)
CORE BITS(DBS)
IMPREGNATED(DIAMOND type)
CUTTERS(PDC type)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CORING TECHNIQUES
AXIAL CORING
CORE BARREL
ADVANTAGES
LIMITATIONS
• ‘CONTINUOUS’ RECORD• Possible ORIENTATED (Dip, Azimuth)• PETROPHYSICAL PROPERTIES
minimally disturbed• Various INNER TUBES:
. Aluminium, Fiberglass
. Rubber sleeve, Sponge, ...
• SLOW and EXPENSIVE• Possible POOR RECOVERY along:
. FRACTURED zones
. UNCONSOLIDATED formations
SIDEWALL
LATERAL CORING
• WIRELINE ACQUISITION• FAST & CHEAP• RUN at ANYTIME (preferably at TD)• SELECTED SAMPLES (after logging)• PERCUSSION or MECHANICAL bullets• Mineralogy studies, ...
• DISCONTINUOUS RECORD• MODERATE RECOVERY
(flushed zone)• NO ‘Phi-K’ ANALYSES
DRILLING Departments ‘prefer not to core; but, they want: «high ROP, long footage, not too many trips, no twist-off, not to be stuck, ...»’ (BHI Coring Seminar)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
... UNDER ‘WELLSITE GEOLOGIST’ RESPONSIBILITY
CORING OPERATION & MUDLOGGING ASSISTANCE
TBnb
1 - BEFORE Coring. CHECK (or prepare) CORE TRAYS on rig floor and/or CORE BOXES:
=> Quantity (length cored + 10%), Order (numbering & labelling). DATABASE: INCREASE SAMPLING RATE => every 0.5m, instead of 1m. CHECK ‘SPP & FR’:
- before dropping the ball: mud circulates through the inner tube- after dropping the ball: mud circulates in annulus, between ‘outer barrel-inner tube’
?
2 - WHILE Coring. ADJUST coring param’ (reduced compared to drilling phase) according to Core-man,. RECORD & MONITOR, as usual, all parameters (including lithological control),. DETECT eventual troubleshootings: core jammed/broken, connections, worn bit, ...
... in order to stop coring, if necessary.
3 - STOP Coring. BREAK the core by pulling up (the core catcher retains the core in the inner tube)
when the core barrel is full or if no more penetration is observed,. PULLING OUT the core assembly WITHOUT CIRCULATING at TD
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CORING OPERATION: RECOVERYUNSLEEVED CORE
B1
Top
T1
Tn Bn
Bottom
LAY DOWNon
DRILL-FLOOR
BETTER OBSERVATIONS ON RIGSITE
CORE-BARREL
CATCHINGCORE BOXES
SLEEVED CORE
LAY DOWNon
PIPE-RACK / WALKWAYHammer,Plastic bags
Electric saw + caps & clipsto seal each section
=> inner tubes: => main use:RUBBER SLEEVE: soft / unconsol. FmFIBER GLASS: more and more usedALUMINIUM: high Temp° FmORIENTED CORING dip, fractur., direct.K, ...Sponge: Fluid recovery (?)
BETTER PRESERVATION for TRANSPORTATION ... ALWAYS UNDER ‘WELLSITE GEOLOGIST’ RESPONSIBILITY
3 - Soft washing with RAGS, BRUSH, Humid Sponge4 - Pieces MATCHING & ORIENTING from Top to Btm into ‘‘DEFINITIVE CORE BOXES’’5 - DRAW ‘Orientation lines’ from TOP to BOTTOM6 - Measuring core & mark depths7 - % recovery= (Recov.Length / Interv.cored) x 100
11-Subsidiary, Well Name, Core Nb, Box nb, T B => note: Never write depths outside boxes
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
SLEEVED CORECORE RECOVERY
=> inner tubes: => main use:RUBBER SLEEVE: soft / unconsol. FmFIBER GLASS: more and more usedALUMINIUM: high Temp° FmORIENTED dip, fractu., direct.K, ...Sponge: Fluid recovery (?)
LAY DOWNon
PIPE-RACK / WALKWAY
CORE-BARREL
BottomTop
Electric saw + caps & clipsto seal each section
BnT1
BETTER PRESERVATION for TRANSPORTATION
METHODOLOGY
CORE MARKING
CHIPS EXAMINATION
CORE TRANSPORTATION
CORE PACKAGING
1 - CLEAR a.s.a.p. pipe-rack area, and move ...2 - DEFINITIVE CORE BOXES to ‘ML Unit’3 - COLLECT core chips every meter and place chips inside plastic bags for examination
4 - DRAW / underlined ‘Orientation lines’ T => B5 - NOTCH up with saw each segment / inner tube => for orientation inside ‘inner tubes’6 - Clean with rags & mark depths on tubes7 - % recovery= (Recov.Length / Interv.cored) x 100
8 - SEAL with caps and clip each segments ends9 - Subsidiary, Core Nb, Well Name, Box nb
note: Never write depths outside boxes
10 - A/A ... and fill in ‘Core Description Sheet’
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CORING: ORIENTING & LABELLING
4
3
2
1
Piecesmatching
3 - 4Good fit
2 - 3Poor fit(one lineeach sideof break)
1 - 2No fit
(two lineseach sideof break)
Orientationlines
LEFT: BLUEor BLACK
RIGHT:RED
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
PRESERVED SAMPLE for SCAL => PHANTOM
… alongGOOD
andPOORfacies
ououHououH
SCAL#1
Btm
SCAL#1
OUCH !
ALUMINIUM FOIL
SCAL
#119
98.5
0-19
98.2
5m
HOOOUU ...!
Btm
CORE
#1
-
box
5/7
TOTA
L O
WL
Lm
td -
well
GHO
ST#1
WAX or PARAFFIN
HOT Bath
Btm
MiaouH
Woou!
SCAL#11998.50 -1998.25m
well: GHOST#1
25 cm
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CORING & LABORATORYPLUGS
CORE
VPLUG
VERTICALH
PLUG
HORIZONTAL
PREFERABLYCUT AT THE
SAME DEPTH
CHIPS USEDFOR
THIN SECTIONS
SMALL CORES CUTINSIDE ‘MAIN CORE’
STRUCTURAL DIP and/or HOLE DEVIATIONNOT TAKEN INTO ACCOUNT
SLABBED SECTIONS
LONGITUDINALCROSS SECTIONS
(for partners, ref., ...)
3 SCRATCHES FORORIENTED CORING
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CORING ORIENTATION: DIP & DEVIATED WELL
αSTRUCTURAL DIP
TMD TVDHORIZONTALSECTION
βDEVIATION
ANGLE
DEVIATION AZIMUTH
γβ
α
( )γ α β= °− +90
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
C O R I N G
IT’S GOODIN ANYCASE,
MY DEARCOLLEAGUE !
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
Reporting ‘DGR’ & Coding ‘DDR’
R E P O R T I N G S U M M A R Y
- GEOLOGY:
. REPORTING ... through AGES!
. CURRENT REPORTING: when? & what to report?
. DGR: Daily Geological Report => CEF/SUB form
- GWR: Geological Well Report
- DRILLING:
. OPERATIONS CODING
. OPERATIONS TIMING: planned & unscheduled
. DDR:Daily Drilling Report => FPL/OPS form (‘DAISY’)
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
GEOLOGICAL REPORTING through AGES
AIM
DAILY INFORM the SUBSURFACE OPERATIONS GEOLOGIST in BASE
HOW ?
YESTERDAY TODAY
Quantity ofdata
transmitted
Datatransfer
equipment
INFO-RIG
RADIO TELEXPHONE
DOCUMENTS
FAX
e-mail
TEP/DEG/CEF/SUB. . . Natters Around Field . . .
CURRENT GEOLOGICAL REPORTING
INFO-RIG DOCUMENTS
WHEN ?
WHAT ?
• ON A BASIS ROUTINE=> TWICE A DAY... on pre-scheduled time
• ON UNUSUAL OPERATION=> AT ANY TIMETD, Logging, Coring point, ...
CURRENT SITUATION• DEPTH (TMD/TVD)• OPERATION IN PROGRESS
with details ... if requested(ROP, litho, intervals shows, ...)