Offshore NW Palawan Basin, Philippines

Rosell, G. B., Mambuay, L. T., Panganiban, D. V. and Sales, A. O. THE PHILODRILL CORPORATION

GEOCON 2019 December 4 – 5 Manila Hotel, Philippines OUTLINE

BACKGROUND Mindoro • SC 6A Petroleum System SEISMIC INTERPRETATION Coron SEISMIC ATTRIBUTES Culion • Amplitude • Spectral Decomposition • Theory

• Results El Nido CONCLUSIONS

KILOMETERS Palawan 0 25 50

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 2 NW PALAWAN PETROLEUM SYSTEM

Schematic diagram of the NW Palawan Petroleum System (Philodrill, 2014; modified from PhilPRA, 2002) ← West Philippine Sea Palawan Island →

S Source Rock R Reservoir Rock KILOMETERS C Cap Rock 0 25 50 100

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 3 NW PALAWAN PETROLEUM SYSTEM

Schematic diagram of the NW Palawan Petroleum System (Philodrill, 2014; modified from PhilPRA, 2002) ← West Philippine Sea Palawan Island →

Cadlao – Matinloc Malampaya – Camago Galoc – Octon

S Source Rock Migration R Reservoir Rock Gas KILOMETERS C Cap Rock Oil 0 25 50 100

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 4 SEISMIC INTERPRETATION Top GCU (TWT)

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 5 SEISMIC INTERPRETATION

MALAJON-1

GCU

+ 1 km

1 km -

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 6 SEISMIC INTERPRETATION

OCTON-2 OCTON-3

GCU

+ 1 km

1 km -

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 7 SEISMIC INTERPRETATION GCUTop Isochron GCU (TWT) (TWT)

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 8 NORTH BLOCK INSTANTANEOUS AMPLITUDES Top GCU (m)

GCU

+ 500 m

1 km -

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 9 NORTH BLOCK INSTANTANEOUS AMPLITUDES Top GCU (Amplitudes)

GCU

+ 500 m

1 km - High

Low

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 10 SOUTH BLOCK INSTANTANEOUS AMPLITUDES Top GCU (TWT)

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 11 SOUTH BLOCK INSTANTANEOUS AMPLITUDES GFU1 Slice (Amplitudes)

12.5 MMCFPD 1037 BCPD 1816 BOPD 1.89 MMCFPD High

Low

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 12 SPECTRAL DECOMPOSITION: Theory

• A reflection from a thin bed, has a characteristic response in the frequency domain that is indicative of that temporal 30 Hz 15 Hz bed thickness (Partyka et al, 1999).

Schematic from: Laughlin et al (2003)

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 13 SPECTRAL DECOMPOSITION: Theory OCTON-2 Synthetic Seismogram • A reflection from a thin bed, has a FOURIER TRANSFORM characteristic response in the frequency

domain that is indicative of that temporal 30 Hz Amplitude 15 Hz bed thickness (Partyka et al, 1999).

GCU • Thin bed: Seismic resolution at the GCU level in SC 6A is ~26 m.

Schematic from: Laughlin et al (2003)

26m

Diagram from ifm.com/en/us

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 14 SPECTRAL DECOMPOSITION: Theory

• A reflection from a thin bed, has a FOURIER TRANSFORM characteristic response in the frequency

domain that is indicative of that temporal Amplitude bed thickness (Partyka et al, 1999).

• Thin bed: Seismic resolution at the GCU level in SC 6A is ~26 m.

• Spectral decomposition utilizes the Fourier Transform to breakdown the waveform.

• Premise: a waveform is a composite expression of multiple sinusoids attuned to different frequencies. Diagram from ifm.com/en/us

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 15 SPECTRAL DECOMPOSITION: Case Study

• Pioneering work done by AMOCO • Pennsylvanian Red Fork Sandstone, Onshore Anadarko basin, USA

Peyton, Bottjier, Partyka (1998) Interpretation of incised valleys using new 3-D seismic techniques: A case history using spectral decomposition and coherency

Partyka, Gridley, Lopez (1999) Interpretational applications of spectral decomposition in reservoir characterization

Peyton et al (1998).

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 16 SPECTRAL DECOMPOSITION NORTH BLOCK G: 26 Hz TOP GCU Dominant Frequency

Esperanza-1

Saddle Rock-1

4 20 40 60 80 100 (Hz)

Malajon-1

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 17 SPECTRAL DECOMPOSITION NORTH BLOCK R: 12 Hz G: 26 Hz B: 40 Hz TOP GCU Dominant Frequency

Esperanza-1

Saddle Rock-1

4 20 40 60 80 100 (Hz)

Malajon-1

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 18 SPECTRAL DECOMPOSITION NORTH BLOCK RGB, Top GCU TOP GCU Dominant Frequency

Esperanza-1 40 Hz

Saddle Rock-1

26 Hz 12 Hz 4 20 40 60 80 100 (Hz)

Malajon-1

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 19 SPECTRAL DECOMPOSITION NORTH BLOCK RGB, -100ms deeper TOP GCU Dominant Frequency

Esperanza-1 40 Hz

Saddle Rock-1

26 Hz 12 Hz 4 20 40 60 80 100 (Hz)

Malajon-1

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 20 SPECTRAL DECOMPOSITION SOUTH BLOCK

GCU

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 21 SPECTRAL DECOMPOSITION SOUTH BLOCK

MID GCU Dominant Frequency

GCU

4 10 20 30 40 50 60 70 (Hz)

20 Hz

16 Hz 10 Hz

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 22 MID GCU (RGB) SPECTRAL DECOMPOSITION SOUTH BLOCK

GCU

20 Hz

16 Hz 10 Hz

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 23 MID GCU (RGB) SPECTRAL DECOMPOSITION SOUTH BLOCK

CHANNEL MARGIN

CHANNEL CORE GCU

20 Hz

16 Hz 10 Hz

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 24 MID GCU (RGB) SPECTRAL DECOMPOSITION SOUTH BLOCK

CHANNEL MARGIN

CHANNEL CORE GCU

20 Hz

16 Hz 10 Hz

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 25 MID GCU (RGB) SPECTRAL DECOMPOSITION SOUTH BLOCK

GCU

20 Hz

16 Hz 10 Hz

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 26 MID GCU (RGB) SPECTRAL DECOMPOSITION SOUTH BLOCK

GCU

20 Hz

16 Hz 10 Hz

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 27 CONCLUSIONS

• Seismic attributes enable interpreters to extract more out of the seismic data. • Spectral decomposition is an effective tool for delineating sedimentological features below the seismic resolution.

• Best applicable to channel geometries in relatively MID GCU (RGB) benign tectonic settings. • Should be targeted: • Horizon pick should be chronostratigraphically accurate • Hard to do in structurally complex areas • Poor seismic • Difficult to map

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 28 THANK YOU! REFERENCES

Hansen, L. A. S., Callow, R. H. T., Kane, I. A., Gamberi, F., Rovere, M., Cronin, B. T., & Kneller, Department of Energy B. C. (2015). Genesis and character of thin-bedded turbidites associated with submarine channels. Marine and Petroleum Geology, 67, 852–879. Service Contract 6A Consortium https://doi.org/10.1016/j.marpetgeo.2015.06.007 Laughlin, K., Garossino, P., & Partyka, G. (2002). Spectral Decomposition for Seismic The Philodrill Corporation Stratigraphic Patterns. AAPG Explorer, 4. Li, F., Qi, J., & Marfurt, K. (2015). Attribute mapping of variable-thickness incised valley-fill The Leading Edge, 34(1), 48–52. https://doi.org/10.1190/tle34010048.1 PetroEnergy Resources Corp systems. McArdle, N. J., & Ackers, M. A. (2012). Understanding seismic thin-bed responses using frequency decomposition and RGB blending. First Break, 30(1956). Anglo Philippine Holdings Corp https://doi.org/10.3997/1365-2397.2012022

Partyka, G., Gridley, J., & Lopez, J. (1999). Interpretational applications of spectral ACE Enexor Inc decomposition in reservoir characterization. The Leading Edge, 18(3), 353–360. https://doi.org/10.1190/1.1438295 Forum Energy Phils. Corp Peyton, L., Bottjer, R., & Partyka, G. (1998). Interpretation of incised valleys using new 3-D seismic techniques: A case history using spectral decomposition and coherency. The Leading Edge, 17(9), 1294–1298. https://doi.org/10.1190/1.1438127 PXP Energy Corp Sprague, A. R. G., Garfield, T. R., Goulding, F. J., Beaubouef, R. T., Sullivan, M. D., Rossen, C., … Mellere, D. (2005, February). Integrated slope channel depositional models: The Alcorn Petroleum and Minerals Corp key to successful prediction of reservoir presence and quality in offshore West Africa. 5.

5 December 2019 GEOCON 2019: SC6A Seismic Attributes 29