November 2019

What's new in exploration

Lions and tigers and bears, oh my!!
William (Bill) Head / Contributing Editor

Bears: The U.S. drilling rig count drops to 830 (Baker Hughes) from an all-time high of 4,530 in 1981. As explorationists travel the yellow-brick road, we have realistic paranoia. Let’s see, oil people are responsible for earthquakes, more CO2 since the Cretaceous, bad water or too much water, global warming or global cooling, and political corruption. Chevron, rejected by Anadarko, buys a Mexican oil “deal” from Shell.  Who won—Mexico or Shell? Create-a-Bear: The U.S. BOEM approves leasing offshore California, ~291,374 hectares, not available since 2013. Intervenors immediately objected in court. 

Tigers? Avoiding Paper Tiger Syndrome is not easy. The SEG Journal, once fun to read, is now a digital publication for the few who actually create geophysics. SEG wiki maintains relevance, but SEG-SEAM cannot find coin-in-the-realm to finish its work started by industry and DOE. Oil companies do not have less money, just less interest in geophysical exploration. Service companies carry most new work, but the market dictates. The Leading Edge popularizes tech to members, along with AAPG/SEG Interpretation. SEG has been increasing its focus on China’s and less-developed countries’ (LDC’s) rank areas. Do we need (Director of the Office of Trade and Manufacturing Policy and Assistant to the President) Peter Navarro to see where that could go?

AAPG may be worse. The AAPG Explorer replaced the case history Bulletin for most members. Geology is going A.I., while surviving oil geologists are retiring. However, AAPG recently jumped on the Transition road away from petroleum: It featured speakers from the Foundation for The United Nations Global Compact, promoting “Geoscientists in the Transition,” and a Shell manager presenting Shell’s UK transition strategy away from oil. Is AAPG trying to survive or sustain? Does “transitioning” mean pulling members away from oil, therefore a self-inflicted reduction in petroleum participation? I think a bit of both, however, increasing university influence in society politics means moving away from oil, e.g. the American Geophysical Union.

Transitioning to what? AAPG explains in Session 4, Key Stakeholders, in this order: 1) UK Academia, 2) Sustainable Industries; Geothermal, Nuclear, Low-Carbon, Environmental, 3) Hydrogeological and Engineering Geology communities, 4) International & National energy companies, 5) Professional Societies (AAPG, Geological Society of London), and 6) External Training Organizations. Perhaps it’s time that AAPG changes its name.

Lions: The SPE publication, JPT, written in Houston, remains a central tech focus for drilling and completion professionals, the majority of WO readers. JPT occasionally ventures into exploration.  I do value SEG lecture/discussion development workshops such as the “SPE/SEG Workshop: Injection Induced Seismicity - The Next Chapter,” Dallas, Texas, USA, November 2019.

Exploration Lion: SPWLA, 61st Annual Logging Symposium, Banff Springs, Alberta, June 20-24, 2020. Papers on: New Borehole Logging Technology; Advances in Machine Learning; Deepwater Reservoir Analysis; Petrophysics in Brownfields; Case Studies; Formation Evaluation Behind Casing; Completion Petrophysics and Reservoir Surveillance; Formation Evaluation of Conventional Reservoirs; and Formation Evaluation of Unconventional Reservoirs.

Geophysicists can stray a bit using seismic images. Reading “Estimation of Thomsen’s Epsilon and Delta in a Single Core Using Ultrasonic Phase and Group Velocity Measurements,” Gabriel Gallardo-Giozza, D. Nicolás Espinoza and Carlos Torres-Verdín, UT-Austin, Elsa Maalouf, Am. U. of Beirut,,  just might make one cautious in asserting seismic, rock physics correlations and expounding on broad inversions. Core: About 4-in. diameter by 12 in. along a 20-ft tube; seismic—about 500-ft diameter of a 125-ft vertical sample along a 12,000-ft wave path. One to one? Hardly. 

Completion cement is the most troubling of all well integrity issues, exploration or production, period.  Advances in reservoir detection behind casing would have to include cement. Some SPWLA contributions from the program include:

“Inversion of High-Resolution High-Quality Sonic Compressional and Shear Logs for Unconventional Reservoirs,” Ting Lei, Smaine Zeroug, Sandip Bose, Romain Prioul and Adam Donald, Schlumberger.

“The Impact of Petrophysical Uncertainty in Formation Evaluation and Reservoir Modeling–A Robust Methodology,” Michele Arcangeli, Niccolò Ceresa, Maria Teresa Galli, Paola Cardola and Paolo Scaglioni, Eni.

“Using a Neural Network to Estimate Net Sand from Borehole Images in Laminated Deepwater Reservoirs,” Bo Gong, Dustin Keele and Emmanuel Toumelin, Chevron, as follows:

Deepwater reservoirs often consist of highly laminated sand shale sequences, where the formation layers are too thin to be resolved by conventional logging tools…This…estimates sand fractions directly from OBM borehole images without extracting an image resistivity curve. The processing is based on an artificial neural network, which takes a 2-D borehole image array as input, and predicts sand fractions by applying a non-linear transformation to all the elements, i.e., electrical measurements from all button electrodes.…quantifying thin sands in the absence of cores…

Of course, there are other papers on “raw” machine learning—or, “how to bust an interpretation and get yourself fired.” A.I. in alpha and beta strives for “good enough,” the enemy of better and best.

About the Authors
William (Bill) Head
Contributing Editor
William (Bill) Head is a technologist with over 40 years of experience in U.S. and international exploration.
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