From time to time, I am asked to address general audiences. The mission is to describe what we do in the seismic business. Typically, the first slide I show is a prenatal ultrasound display of my daughter. I explain that using reflected sound waves to create such an image is precisely what we do with the Earth. The world’s first reflection seismic field tests were conducted near Oklahoma City in 1921, and, ever since then, the industry has endeavored to improve that seismic imaging process.
So, indeed, one of the papers selected for this Technology Focus section and one of the papers recommended for additional reading deal with case histories in which imaging is improved through better velocity-model building. In the first paper, integration of microgravity data, resistivity measurements, and seismic is the key in the onshore case history from Qatar. In the first additional-reading paper, full-waveform inversion of seismic travel times and amplitudes is the key in the case history from offshore Australia.
Advances in seismic applications are not just confined to imaging, though. In another additional-reading paper, amplitudes are used for identifying porous zones in an otherwise tight-sandstone gas reservoir in Oman. And, in the third additional-reading paper, the authors use the amplitudes in 4D analyses for identifying new reservoir drive mechanisms in a field offshore Brunei
Both imaging and amplitude inversion benefit greatly from broader-band data. Therefore, this is the topic of the second paper presented. In this example from offshore Malaysia, the marriage of a new acquisition technique with new processing algorithms yields broader frequency content, enabling more-accurate estimates of gas in place to be derived.
But even further advances in seismic applications are taking place now, especially in the world of unconventional resources. The authors of the third selected paper discuss the integration of microseismic data with 3D-seismic attributes, well-log data, and completion data to understand the geomechanical rock properties in the Midland basin of Texas. This information was important for planning the spacing of new wells.
I hope this journey is successful in showing that substantial advances continue to be made globally in seismic applications. But, perhaps even more importantly, I hope the journey shows that some of the more exciting advances are actually arising from the integration of seismic with other technologies and that, while imaging may still be king in seismic (and in some fields of medicine), the applications of seismic to building 3D mechanical Earth models, for example, are gaining prominence.
IPTC 17905 High-Resolution Anisotropic Earth-Model Building on Conventional Seismic Data Using Full-Waveform Inversion: A Case Study Offshore Australia by Bee Jik Lim, Schlumberger, et al.
SPE 177552 Seismic Reservoir-Quality Prediction, Khazzan Field, Oman by T. Chris Stiteler, BP, et al.
IPTC 18491 4D Seismic in Stacked Reservoirs—From Puzzles to Insights on Production Drive Mechanisms by Denis Kiyashchenko, BSP, et al.
Mark Egan, SPE, retired from Schlumberger in January 2016. He had worked for Schlumberger and its heritage companies since 1975, with his last position being global chief area geophysicist in the Land Unconventionals Group within the WesternGeco segment. Egan’s previous postings with Schlumberger included positions as chief geophysicist in North America; Saudi Arabia; Dubai; and Gatwick, England. He holds a PhD degree in geophysics, an MS degree in acoustics, and a BS degree in physics and math. Egan is a member of the JPT Editorial Committee.
Mark Egan, SPE, Retired
10 February 2016