John D. Pigott

Basin Analysis and Seismic Stratigraphy

Prior to joining the faculty of the School of Geology and Geophysics, I was a basin analyst and seismic stratigrapher with Amoco International Oil Company, evaluating the hydrocarbon potential of Southeast Asia. This interest has continued as I integrate geology, geophysics, and geochemistry into the evaluation of the tectonic evolution and hydrocarbon potential of sedimentary basins worldwide. Owing to a certain predisposition toward carbonates, my geographic areas of study tend to be latitudinally restricted to within 30 degrees of the paleo- or present day equator. Longitudinally, investigations have circumnavigated the globe, ranging from Jamaica to Guatemala to Colombia to Argentina to Tahiti to Papua New Guinea to the South China Sea to the Gulf of Thailand and to the Red Sea.

One example of my integrated basin analysis-seismic stratigraphy research is a field program within the Ramu-Sepik Basin of Papua New Guinea. The outcrop, structural, and petrologic data are combined with reflection seismic data to constrain the dynamic evolution of this complicated convergent-margin setting. In addition, these data also provide insight into the spatial and temporal distribution of the hydrocarbon potential of this tectonically wrenched region, analogous in many respects to the prolific Los Angeles Basin of North America. In the South China Sea and Gulf of Thailand co-workers and I are unraveling the history of basin response to propagative extrusion tectonics using an inventory of reflection seismic and well bore hole data and state-of-the-art basin modeling software.

A particularly exciting and new development in my basin research is the recent work in the Middle East. Presently, under the auspices of the United Nations - World Bank, I am supervising the processing and interpretation of some 100o km of seismic data from the Red Sea - Gulf of Aden, a program of research and technology transfer with member nations funded by a consortium of international oil companies. Results from subsalt seismic stratigraphy have constrained regional basin models which reveal the impact of evaporites on polyphase rifting and heating events in the Red Sea. Additional geophysical efforts include processing and interpretation of ground-penetrating radar (120 MHz), geophysical reservoir characterization using detailed velocity analysis, the extraction of elastic properties of rocks and fluids through the inversion of amplitude versus offset AVO 2-D and 3-D seismic data, and the optimization of fault obscurred and subsalt imaging using prestack depth migration.

Emphasizing didactics over pedantic pedagogy, I teach courses in basin analysis, seismic stratigraphy, 2-D and 3-D seismic processing and interpretation, and tectonics.

Selected Publications

Pigott, J.D., 1995, A seismic classification scheme for clastic shelf wedges (Deltas), in M.N. Oti and G. Postma, eds. Geology of Deltas, Balkema, Roterdam, p. 17-29.

Pigott, J.D. and Sattayarak, N., 1993, Aspects of sedimentary basin evolution assessed through tectonic subsidence analysis; Example: Northern Gulf of Thailand, Journal Southeast Asian Earth Sciences, 8, p. 407-420.

Warwick, R.A. and Pigott, J.D., 1990. Interpretation of lateral variations in carbonate porosity by detailed stacking velocity analysis: Mississippian bioherm example, Hardeman Basin, Texas, in Estimation and Practical Use of Seismic Velocities, EAEG/SEG Research Workshop, Cambridge, England, p. 460-469.

Pigott, J.D., Shrestha, R.K., and Warwick, R.A., 1990, Direct determination of carbonate reservoir porosity and pressure from AVO inversion, SEG 60th Annual International Meeting, 2, p. 1533-1536.

Ru, Ke and Pigott, J.D., 1986, Episodic rifting and subsidence in the South China Sea: American Association of Petroleum Geologists Bulletin, 70, p. 1136-1155.

Cullen, A.B. and Pigott, J.D., 1989, Post-Jurassic tectonic evolution of Papua New Guinea: Tectonophysics, 162, p. 291-302