DSI* Dipole Shear Sonic Imager
13 ft Cartridge 18 ft Receiver section 42 in. 3.5 ft 16.5 ft 9 ft to monopole transmitter 11 ft to upper dipole 11.5 ft to lower dipole Transmitter section 16.5 ft 3.5 ft 18 ft 13 ft 42 in. 6 in. Cartridge
Wave Propagation At Rest Compressional Shear
Sin 1 = C1 / C2 Sin 1 = Vmud / VFormation
Hard Formation — Monopole Wellbore Compressional wave Hard Formation — Monopole Head waves Formation Shear wave Fluid wave Omnidirectional source Compressional wave Shear wave Stoneley wave
Fast Formation —Monopole 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Compressional body wave Fast Formation —Monopole Compressional head waves Shear head wave Shear body wave Compressional: 76 sec/ft Shear: 139 sec/ft Fluid: 200 sec/ft Borehole diameter: 10 in. Time: 1 msec Source: 12-kHz monopole 0.0 0.5 1.0
Soft Formation — Monopole Wellbore Formation Soft Formation — Monopole Compressional wave Head wave Fluid wave Omnidirectional source Shear wave Compressional wave Stoneley wave
Slow Formation— Monopole 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Compressional body wave Slow Formation— Monopole Compressional head wave Fluid modes Compressional head wave Fluid head wave Shear head wave absent Compressional: 157 sec/ft Shear: 300 sec/ft Fluid: 200 sec/ft Borehole diameter: 12 in. Time: 2 msec Source: 12-kHz monopole Sin 1 = Vmud / VFormation 0.0 0.5 1.0
DSI Transducer Propagation Borehole Mud Mud Transmitter Flexural Wave Displacement
Soft Formation — Dipole Wellbore Formation Compressional wave Soft Formation — Dipole Head wave Shear wave Flexural wave Directional source Compressional wave Shear wave Flexural wave
Slow Formation— Dipole Compressional: 157 sec/ft Shear: 300 sec/ft 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Slow Formation— Dipole Compressional body wave Shear body wave Flexural mode Compressional: 157 sec/ft Shear: 300 sec/ft Fluid: 200 sec/ft Borehole diameter: 12 in. Time: 2 msec Source: 12-kHz monopole 0.0 0.5 1.0
Slow Formation— Monopole Fast Formation —Monopole 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Compressional body wave Compressional body wave Compressional body wave Compressional head wave Compressional head waves Fluid modes Compressional head wave Shear head wave Shear body wave Fluid head wave Shear body wave Shear head wave absent Slow Formation— Monopole Fast Formation —Monopole Flexural mode Slow Formation— Dipole 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Dipole Waveforms—Fast Formation Shear Flexural Mode
Principal tool combinations AIT* Array Induction Imager Tool ARI* Azimuthal Resistivity Imager tool Auxiliary Measurements Sonde Compensated Neutron Log FMI* Fullbore Formation MicroImager tool Gamma Ray General Purpose Inclinometry Tool (GPIT) IPL* Integrated Porosity Lithology tool Phasor* Induction tool UBI* Ultrasonic Borehole Imager tool USI* UltraSonic Imager tool DSI Tool 13 ft Cartridge 18 ft Receiver section 42 in. 6 in. 11 ft to upper dipole transmitter Isolation joint 9 ft to monopole transmitter 3.5 ft 11.5 ft to lower dipole transmitter 16.5 ft Transmitter section
Tool Combinations AIT* Array Induction Imager Tool ARI Azimuthal Resistivity Imager tool Auxiliary Measurements Sonde FMI Fullbore Formation MicroImager tool Gamma ray General Purpose Inclinometry Tool (GPIT) IPL Integrated Porosity Lithology tool Phasor Induction tool UBI UltraSonic Borehole Imager tool USI UltraSonic Imager tool
Tool Specifications Temperature rating 350°F [175°C] Pressure rating 20,000 psi [138 MPa] Tool diameter 35/8 in. [9.2 cm] Minimum hole size 51/2 in. [13.9 cm] Maximum hole size 21 in. [53.3 cm] Tool length 51 ft [15.5 m] Maximum logging speed One eight-waveform set 3600 ft/hr (single mode) All six modes simultaneously, 900 ft/hr without 6-in. Dt Digitizer precision 12 bits Digitizer sampling interval limits Variable from 10 to 32,700 µsec per sample Digitized waveform duration limits Up to 15,000 samples/ all waveforms Acoustic bandwidth Dipole and Stonely 80 Hz to 5 kHz High-frequency monopole 8 to 30 kHz Combinability All MAXIS tools, any resistivity tool
Tool Operating Modes Upper and lower dipole modes Crossed dipole mode (BCR) Stoneley mode P and S mode First motion mode
STC Computation Varying moveout Varying time
(Semblance Contour Plot) STC Contour Plot STC Dot Log Comp Shear ST Plane (Semblance Contour Plot) Depth Z Depth Slowness Z Arrival time Slowness
STC Planes 0.5 to 1.5 kHz 1 to 2 kHz Slowness (sec/ft) Time (sec) 800 Slowness (sec/ft) 100 14,000 14,000 Time (sec) Time (sec)
Slowness Time Plane Projection Poisson's Ratio Delta-T Comp. .25 .50 100 200 Gamma Ray Delta-T Shear 0 100 100 500 Caliper Dtc Coherence Dts Slowness Time Plane Projection Log Quality Indicators 6 16 0 1. 1. 0 10200 10250 10300 10350
Slowness Bias Bias Before Filtering 320 Bias After Filtering 300 Bias After Filtering Flexural Mode Slowness Formation Shear Slowness 0 2 4 6 8 10 Slowness Bias Frequency (kHz) STC Filter Response Unfiltered Amplitude Spectrum Filtered Amplitude Spectrum 1 0.5 Noise Amplitude Spectrum 0 2 4 6 8 10 Frequency (kHz)
Borehole Compensation Formation Interval Measured Receiver Array Pseudo Transmitter Array
DFMD First arrival Rc 8 Rc 7 Threshold crossing Rc 6 Rc 5 Rc 4 Rc 3
Applications Mechanical property analysis — Wellbore stability — fracture height — Sanding Analysis — Azimuthal Anisotropy Formation evaluation — gas detection — fractures Evaluation — permeability Geophysical interpretation — synthetic seismograms — VSP — AVO
Dynamic Elastic Properties Lateral strain 1/2 (DTS / DTC) 2 – 1 Longitudinal strain (DTS / DTC) 2 – 1 v Poisson’s Ratio G Shear Modulus E Young’s Modulus Kb Bulk Modulus Cb Bulk Compressibility (with porosity) Applied stress a b Shear strain DTS 2 Applied uniaxial stress Normal strain 2G (1 + v) [ ] Hydrostatic pressure Volumetric strain 1 4 DTC2 3DTS2 b x a Volumetric deformation Hydrostatic pressure 1 Kb Note: coefficient a = 1.34 x 1010 if pb in g/cm3 and DT in µs/ft.
[ ] 1 4 DTC2 3DTS2 K = b x a a b DTS2 G = s E = 2G (1 + v) 1/2 (DTS / DTC) 2 – 1 (DTS / DTC) 2 – 1 v =
Combined Model Min. Safe Mud Weight/Shear 0 p.u. 100 IMPACT Log (Integrated Mechanical Properties Analysis Computation Technique) Max. Safe Mud Weight/Shear Poisson's Ratio Hole Profile 0 5 Young's Modulus Max. Safe Mud Weight/Tensile Depth 0 106 psi 10 Shear Modulus Mud Weight –25 in. 25 0 106 psi 5 1000 ft
Anisotropy
Cross Dipole Acquisition (BCR)
Anisotropy Processing Result
Gas Detection
3.5 3.0 2.5 2.0 1.5 vp/vs versus Dtc Anthydrite 50 100 150 ²tc
vp/vs versus Dtc 3.0 2.5 2.0 1.5 50 100 150 Shales Unconsolidated sediments 40 35 vp/vs 30 90 ø Wet Wet sandstones 80 Dry gas Sxo Limestone Anhydrite Dolomite Salt Quartz 70 20 Gas 60 50 10 40 Dry (or gas sandstones 50 100 150 ²tc
Fracture Evaluation Hole Diameter 2 (IN) 7 Gamma Ray Stoneley Ref. Coef. STONELEY WF1 0 (GAPI) 150 0 0.15 0 (US) 20000 Fracture Evaluation 600 700 800
Fracture Evaluation
Fracture Evaluation
Fracture Evaluation (SonFrac)
Stoneley Permeability (StPerm)
Stoneley Permeability
Stoneley Energy Gamma Ray Resistivity 6300 6400 7100 Stoneley Density-Neutron Stoneley Energy Differential Energy
AVO Response OFFSET ANGLE (DEG) 2400 4.8 4.5 4.3 4.0 3.8 3.5 3.3 3.0 1 1 2 1 5 0 5 0 2400 4.8 4.5 4.3 4.0 3.8 3.5 3.3 3.0 2.8 2,5 2.3 2.0 1.8 1.5 1.3 1.0 0.8 0.5 0.3 2500 2600 2700 0 2 4 6 8 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 GRADIENT INTERCEPT PRODUCT NOR POLARITY OFFSET ANGLE (DEG) HYDROCARBONS POROSITY MATRIX SHALE SPECIAL MINERAL
Synthetic Seismograms Compressional Shear 1.600 1.700 1.800 1.900 2.000 2.100 2.200 2.300 2.400 2.500 2.600 2.700 2.800 2.900 3.000 3.100 Synthetic Seismograms 8000 9000 10000 11000
DSI Dipole Shear Sonic Imager Monopole compressional and dipole shear measurements provide sonic data in hard and soft formations Applications — Mechanical property analysis — Formation evaluation — Geophysical applications