Local Data - Subsurface Subsurface Measurements/Observations Data from Wells cores, cuttings, logs lithology, ages, geochem, etc Geophysical Data Seismic (2D, 3D, 4D) Gravity & Magnetics SLIDE 6 A major source of data is subsurface measurements and the resulting interpretations Subsurface Measurements/Observations Data from Wells Rock samples from cores and cuttings Measurements from subsurface rock units via logs Interpretations of lithology, ages, geochem, etc. Geophysical data, usually collected at the Earth’s surface Seismic data (2D, 3D, 4D) Gravity & Magnetics Logging a Well Vibrators – Seismic Sources Courtesy of ExxonMobil L 3 - Types of Data