Upscaling Petrophysical Properties to the Seismic Scale Greg

Upscaling Petrophysical Properties to the Seismic Scale Greg A. Partyka, Jack B. Thomas, and Kevin P. Turco, bp Dan J. Hartmann, DJH Energy Consulting

Seismic Reservoir Imaging 8 hz Spectral Amplitude Map Zone 1 WELL #1 1 mile

Seismic Reservoir Imaging Petrophysics ? Stratigraphy SEISMIC Structure • Sensitivity Issues: – Do acoustic properties respond to variability in petrophysical properties? • Scale Issues: – How much seismic resolution is required?

Uncertainty and Errors are embedded at all measurement scales. Measurement Scale Uncertainty/Error Examples microns-to-centimetres sampling bias; damaged plugs WELL-LOG SCALE centimetres-to-metres washouts; tool problems SEISMIC SCALE metres-to-decimetres acquisition & processing artifacts CORE SCALE

Upscaling • Three Steps: 1. Scoping at the well-log scale. 2. Determining upscaling sensitivity. 3. Predicting petrophysical properties from seismic impedance.

Scoping at the Well-Log Scale • Cross-plot well-log-scale acoustic properties versus petrophysical properties. Are acoustic measurements sensitive to petrophysical properties at the well-log scale? NO Seismic will provide little value Game Over YES Hope for seismic detection/resolution Game Continues to Next Step

Seismic Reservoir Imaging 8 hz Spectral Amplitude Map Zone 1 WELL #1 1 mile

Scoping at the Well-Log Scale Backus Averaged Acoustic Properties overlying shale Zone 1 reservoir underlying shale Vp=7445 ft/s Vs=3115 ft/s Den=2. 23 gm/cc Vp=6755 ft/s Vs=3485 ft/s Den=2. 17 gm/cc Vp=7945 ft/s Vs=3260 ft/s Den=2. 26 gm/cc

Scoping at the Well-Log Scale Water Saturation Acoustic Impedance • Zone 1 Thickness = 57 feet • Backus Filter = None Effective Porosity

Upscaling • Three Steps: 1. Scoping at the well-log scale. 2. Determining upscaling sensitivity. 3. Predicting petrophysical properties from seismic impedance.

Upscaling Sensitivity THICKNESS VELOCITY RESOLUTION BANDWIDTH FLOW-UNIT STACKING

Upscaling Sensitivity Analysis • As we scale-up the acoustic data (e. g. bandlimit or decrease thickness): – acoustic resolution of petrophysical properties degrades.

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 057 ft Backus Filter = None 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 100 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 090 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 080 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 070 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 060 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 040 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 030 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 020 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 010 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 010 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 020 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 030 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 040 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 050 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 060 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 070 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 080 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 090 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

1. 00 24, 000 0. 83 23, 000 22, 000 20, 000 0. 50 19, 000 18, 000 0. 33 17, 000 16, 000 0. 17 15, 000 14, 000 13, 000 12, 000 0. 1 0. 2 Effective Porosity 0. 3 0. 4 Water Saturation 0. 67 21, 000 0. 00 Gross Reservoir Thickness (ft) Acoustic Impedance Backus Filter (Hz) Zone 1 Thickness = 100 ft Backus Filter = 050 Hz 100 80 60 40 20 20 40 60 80 100

Upscaling • Three Steps: 1. Scoping at the well-log scale. 2. Determining upscaling sensitivity. 3. Predicting petrophysical properties from seismic impedance. y x depth SEISMIC IMPEDANCE y x depth PETROPHYSICAL PROPERTY RESERVOIR ASSESSMENT

To Predict Petrophysical Properties from Seismic • Requires: – seismic wavelet, – seismic-derived impedance, – upscaling sensitivity relationships, and – gross thickness.

Thickness Estimation • Spectral Decomposition – to compute a Tuning Cube for the zone-of-interest. • Thickness Modeling – to derive amplitude vs thickness vs frequency relationships. • Thickness Calibration – to determine gross reservoir thickness.

Spectral Decomposition z y x 3 -D Seismic Volume Interpreted 3 -D Seismic Volume z y x Subset Zone-of-Interest Subvolume z y x Compute Zone-of-Interest Tuning Cube (cross-section view) Frequency Slices through Tuning Cube (plan view) y x freq Animate y x freq

Zone 1 08 hz spectral amplitude 1 Well # 1 0 1 mile

Zone 1 10 hz spectral amplitude 1 Well # 1 0 1 mile

Zone 1 12 hz spectral amplitude 1 Well # 1 0 1 mile

Zone 1 14 hz spectral amplitude 1 Well # 1 0 1 mile

Zone 1 16 hz spectral amplitude 1 Well # 1 0 1 mile

Zone 1 18 hz spectral amplitude 1 Well # 1 0 1 mile

Zone 1 20 hz spectral amplitude 1 Well # 1 0 1 mile

Thickness Estimation • Spectral Decomposition – to compute a Tuning Cube for the zone-of-interest. • Thickness Modeling – to derive amplitude vs thickness vs frequency relationships. • Thickness Calibration – to determine gross reservoir thickness.

Thickness Modeling Seismic Modeling (Zone 1) 0 shale sand oil Frequency (hz) depth (feet) 1 Two-Way Traveltime (ms) Well-Log Interpretation (Zone 1) 0 50 amplitude 1 100 0 -1 150 200 0 10 20 30 40 50 60 70 Temporal Wedge Model 6 hz amplitude 8 hz 1 0 Spectral Signatures 0 20 40 60 80 Gross Pay Thickness (ft) 100

Thickness Estimation • Spectral Decomposition – to compute a Tuning Cube for the zone-of-interest. • Thickness Modeling – to derive amplitude vs thickness vs frequency relationships. • Thickness Calibration – to determine gross reservoir thickness.

Thickness Calibration Modeled Spectral Signatures vs Thickness 06 hz Spectral Amplitude Zone 1 0. 008 1 Amplitude 0. 007 0 WELL #1 0. 006 0. 005 8 hz amplitude 8 hz 6 hz amplitude 6 hz Frequency (hz) 0. 004 1 mile 08 hz Spectral Amplitude Zone 1 Gross Reservoir Thickness from 6 hz and 8 hz energy WELL #1 Zone 1 1 mile WELL #1 0 50 100 1 mile 0. 003 0 10 20 30 40 50 60 70 80 90 100 Gross Reservoir Thickness (ft)

To Predict Petrophysical Properties from Seismic • Requires: – seismic wavelet, – seismic-derived impedance, – upscaling sensitivity relationships, and – gross thickness.

For Example: frequencyupper = 50 hz thickness = 80 ft impedance = 15, 000 0 Zone 1 50 100 Impedance Thickness (ft) Gross Thickness Then: effective porosity = 0. 2 Zone 1 Thickness = 40 ft; Backus Filter = 50 Hz Well #1 1 mile Effective Porosity Petrophysical Property at the Seismic Scale Acoustic Impedance Zone 1 Thickness = 80 ft; Backus Filter = 50 Hz Effective Porosity Note: Scale-induced uncertainty manifests itself along the axis that represents the smallest scale of measurement. Upscaling Cross-Plots 1 mile Acoustic Impedance If:

Summary • By example we have shown that with proper upscaling, it is possible to merge: – seismic data, – well-log data, – petrophysical data, and – geologic data, into a better calibrated model.

Summary • This interdisciplinary approach can be adjusted for specific fields by calibrating the flow-units. • Uncertainty and errors are embedded at all measurement scales. • Quality of upscaling is dependent on the degree to which petrophysical cross-plots are representative of reservoir flow-units.