sonicscope the next generation of sonic while...
TRANSCRIPT
SonicScopeThe Next Generation ofSonic While Drilling
Meretta Qleibo
LWD Petrophysics Domain Champion
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Why Multipole? Why SonicScope?
─GoalProvide high data quality in real time
Deliver a robust compressional and shear measurement for allformations, irrespective of mud type
─Obtaining reliable compressional and shear providesPore pressure trends
Borehole stability analysis
Gas detection/saturation
Advanced drilling optimization/fracture gradient
Advanced formation evaluation
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From Monopole to Multipole
SonicScope• Multipole tool
• Vp & Vs in all formations
• Enhanced real-time delivery
• Stoneley
sonicVISION• Monopole tool
• Enhanced real-time delivery
• Vp & Vs in “fast” formations
iSONIC• First LWD sonic tool
• Monopole tool
• Vp only
1996
2004-2008
2008onwards
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Dispersive Waves, Flexural and Quadrupole Modes
─ Slowness of the wave varies with frequency
Stoneley wave
Dipole flexuralwave
Quadrupole wave
Dipole flexuralDipole flexural QuadrupoleQuadrupole
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Why Quadrupole and Not Dipoles for LWD?
Wireline tool Drill Collar
Frequency
Wirelinetool flexural
Borehole flexural
Formation shear
No interference
Wireline dipole
Slo
wn
ess
Collarflexural
StrongCoupling
LWD dipole
Slo
wn
ess
Frequency
Fast collarflexural mode
Boreholeflexural mode
Boreholequadrupole
Collar quadrupole
Slo
wn
ess
LWD quadrupole
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SonicScope 825 – Key Technologies
• 12 levels spaced at 90 degrees, 48 receivers total• Industry best 4” inter-receiver spacing, aliasing completely eliminated• Signal digitized at the receiver enables faster downhole processing• 4 bulkheads vs. 28 for QBAT = stronger collar, simpler acoustic modeling
• High power to excite Quadrupole in slow formations• Situated close to the receiver section to overcome attenuation
• Monopole collar arrival suppressed as low as possible• I.D. optimized to separate QP propagation modes• Enables Automatic Labeling, STC threshold
Dual Layer Quadrupole Transmitter “G42” Receiver Belts
Screw on Centralizers Optimized Attenuation Section
• Ensure mode purity• Wellsite Changeable• Hard Faced
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Quadrupole Shear Inversion
─ Model-Based Inversion
Dispersive approach
Account for tool presence effect
─ Tool Presence
Tool equivalent model
Includes all tool details
─ Quadrupole Inversion Methodology
Homogeneous Isotropic model
Tool equivalent model
Maximizing the semblance
Boreholequadrupole mode
Mode Search RZX Modeling
Note: Size of the dots indicate energy
Frequency (kHz)
Slo
wn
ess
(us/
ft)
Shear value
Modeled Quadrupole Mode
Real Quadrupole Data
Slo
wn
ess
(us/
ft)
Frequency (kHz)
Shear value
Model HI
Measured Data
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Local Data Review – SonicScope825
North West Shelf well
12 ¼” hole section, near vertical
Fast and slow formations
Wireline logging suite included Sonic Scanner
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Compressional delivered in real time
Coherency plot and pumps off transmitted toenable QC of the data
Pumps off test performed every stand
Real time applications include seismic tie ins,pore pressure modeling and geomechanics
Real Time Operations
40 us/ft 240
PS
P
(RT)DTCO, DTSM
(RT)
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Data analysis of high-frequency monopole
PS
Stoneley
SlowFormation
P St
P S St
P
S
St
P
St
FastFormation
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Data analysis of high-frequency monopole
FastFormation
SlowFormation
P St
P S St
P
S
P
St
St
P
S
St
P
St
S
P
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LWD(RT)
LWD(REC)
WL
• Comparison between SonicScope Realtime, memory data, and Sonic Scannerlog (Monopole only)
• Memory data from SonicScope and SonicScanner show excellent agreement
• Real Time data quality is as good asmemory mode data
• Shear data is available in Real Time fromMonopole only (fast formations)
Sonic Scanner ComparisonFast Formation, Monopole
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• Comparison between SonicScope 825Real time, memory data, and SonicScanner log (Monopole only)
• Monopole data in slow formation will not giveshear if Shear DT > Mud DT
• Compressional from Monopole approachingmud DT requires Leaky-P processing
LWD(RT)
LWD(REC)
WLSonic Scanner ComparisonSlow Formation, Monopole
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• SonicScope Quadrupole shear shows anexcellent match to Sonic Scanner Dipoleshear
• Shear DT acquired up to 540 us/ft
LWDQuadrupole
WL DipoleSonic Scanner ComparisonSlow Formation, Quadrupole
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• Sonic Scope service is now available in 4.75” and8.25” collars
• Robust compressional delivered to client in real time
• High quality waveforms enable data analysis and QC
• Excellent Agreement between SonicScope andWireline Sonic Scanner
Summary