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Petrophysics and Well Logs

Explorer Emphasis Article

Nuclear magnetic resonance tools are becoming a standard part of the logging suite for many oil companies, and for good reason.

American Association of Petroleum Geologists (AAPG)
Explorer Emphasis Article

Pushing the technological envelope has helped to build the petroleum industry. Today NMR is one of the cutting edge technologies that is changing the face of well logging.

American Association of Petroleum Geologists (AAPG)
Explorer Geophysical Corner

This month's column is titled 'Crooks Gap Field; Limitations of 3-D Seismic Interpretation.'

American Association of Petroleum Geologists (AAPG)
Explorer Article

One hundred years of petroleum exploration and development in the Los Angeles region have produced a rich legacy of geological and geophysical data -- a legacy that the oil industry has spent billions of dollars to obtain.

American Association of Petroleum Geologists (AAPG)
Explorer Article

When it comes time to clean out the basement, people usually throw out the 'old' stuff. After all, it's been in a basement untouched for more than 30 years, how much could it really be worth?

American Association of Petroleum Geologists (AAPG)
Explorer Article

In this computer age it's easy to lose sight of the all-important fact that those gee whiz computer graphics and models that so beautifully depict the subsurface of the earth still have to start with the basics. The geologic data and rocks.

American Association of Petroleum Geologists (AAPG)
Explorer Wildcat Recollections Column

New computer programs were designed by Shell Oil during that decade to measure seismic amplitude changes and pay thickness, and -- most importantly -- seismic data was being calibrated with petrophysical data.

American Association of Petroleum Geologists (AAPG)
Explorer Emphasis Article

Compare 1,200 well logs in two days. Mission: Impossible? Doesn't have to be.

American Association of Petroleum Geologists (AAPG)
Explorer Emphasis Article

To ensure safe operation of underground salt caverns -- whether they're used for storage or brine production -- cavity surveillance via sonar data to detect changes in the cavities is a routine procedure for prudent operators.

American Association of Petroleum Geologists (AAPG)
Explorer Wildcat Recollections Column

This is the first of three articles on the application of 'bright spot' technology, which helped Shell Oil Company discover many large oil and gas fields in the Gulf of Mexico during the late 1960s to the late 1980s.

American Association of Petroleum Geologists (AAPG)
Field Seminar
Muscat, Oman
Sunday, 5 April 2026, 8:00 a.m.–4:30 p.m.

This one-day advanced course delivers a focused and highly practical framework for interpreting structural styles in the Middle East, combined with the unique advantage of applying Generative AI (GenAI) to elevate geological understanding and decision-making. Built for geoscientists working in exploration, development, or basin modeling, the course emphasizes practical techniques, hands-on interpretation, and modern tools that increase accuracy, speed, and confidence in structural workflows. We begin with a foundational module designed to unify all participants, regardless of background, around the principles of fault mechanics and structural style recognition. Participants will revisit faulting fundamentals, mechanical stratigraphy, and structural style classification. The goal is to align interpretation techniques with geological processes, and to establish a shared vocabulary for the day. An introduction to GenAI highlights its role in managing structural ambiguity and enhancing workflows, helping geoscientists clarify options when data is incomplete or conflicting. Normal Faulting Through a sequence of focused exercises, participants explore fault segmentation, growth history, and interpretation in extensional domains. This segment reinforces practical skills in identifying and validating fault geometries in map and section views. GenAI is introduced as a scenario-building tool: participants will use it to explore structural uncertainty, generate alternative models, and compare extensional interpretations, all using fragmented or incomplete datasets, not as a seismic interpreter but as a powerful thought partner. Strike-Slip and Transtension This module targets the complexity of strike-slip and transtensional systems. Participants learn to distinguish pure strike-slip geometries from transtensional overprints, assess compartmentalization, and model realistic deformation patterns. Interpretation exercises develop structural reasoning in map and cross-sectional views. GenAI is applied here to integrate multi-source inputs, such as field data, analogs, and internal reports, to support rapid synthesis and generate testable structural concepts. Salt Tectonics The final segment introduces key diagnostic features of salt-related deformation: welds, reactive and passive diapirs, and halokinetic sequences. Exercises train participants to recognize salt-influenced geometries and link them to broader structural evolution. GenAI then supports pattern recognition and memory mining, leveraging archived knowledge from prior studies, case histories, and analog reports to help geoscientists build and validate interpretations faster and with more confidence. What makes this course different? This is not a theoretical seminar. It’s a learning accelerator, where foundational concepts are applied in realistic interpretation settings, then extended with state-of-the-art GenAI capabilities. You’ll not only sharpen your structural reasoning, but learn how to delegate time-consuming tasks, like synthesizing legacy reports, generating alternative scenarios, or exploring interpretation options, to an intelligent AI partner. By the end of the day, participants will: Recognize and differentiate key fault styles with confidence Improve fault interpretation quality and geological risk assessment Use GenAI to test structural scenarios and extract insight from fragmented or incomplete datasets Accelerate their ability to interpret, communicate, and make decisions in structurally complex plays This course equips you with what matters most today: deep geological understanding, elevated by the best of modern AI. Who Should Attend and Why This course is ideal for both new hires and experienced geoscientists working across exploration, development, and reservoir modeling. Its exercise-driven format ensures that participants with diverse backgrounds, geologists, geophysicists, geomodelers, can engage, learn, and apply. While some familiarity with geosciences is beneficial, prior structural geology training is not required. What makes this course indispensable is its ability to bridge theory and practice: participants will gain a clear understanding of how rocks deform over time, how fault geometries evolve, and how these structures influence seismic interpretation, mapping, and static/dynamic modeling. By integrating real case studies and GenAI-enhanced workflows, the course delivers practical tools to improve subsurface outcomes and build models that match project maturity and business objectives. Main Objective This course delivers the structural geology foundations every geoscientist needs to confidently interpret faults and build or validate static models. Derived from decades of project reviews, interpretation support, and applied field experience, these “must-know” concepts include fault mechanics, growth, segmentation, and structural style recognition, relevant to both exploration and production settings. Participants will strengthen their ability to recognize deformation styles, interpret fault geometries in map and section view, assess mechanical stratigraphy and reactivation risk, and QC interpretations with confidence. Throughout the course, GenAI is introduced not as a software tool, but as a workflow enhancer, used to reduce ambiguity, test structural hypotheses, and extract insight from fragmented datasets or legacy documentation. This empowers geoscientists to think more clearly, work more efficiently, and improve the geological soundness of their models. Key Points Date: 5th April,2026 Venue: Crowne Plaza Hotel, OCEC Registration Fee: $590 Registration Deadline: 22nd February,2026 *Registration will be opening shortly Instructors Pascal Richard PRgeology Jan Witte Falcon-Geoconsulting

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American Association of Petroleum Geologists (AAPG)
Field Seminar
Muscat, Oman
Thursday, 9 April Friday, 10 April 2026, 7:30 a.m.–7:00 p.m.

The Jabal Akhdar in the Central Oman Mountains forms a ~90 km × 60 km dome. The core of this dome consists of Cryogenian to Ediacaran siliciclastics and carbonates, including source rocks. These rocks are separated from the overlying rocks by a spectacularly exposed angular unconformity. The rocks above this unconformity are Permo-Mesozoic shelf carbonates of the Arabian passive margin. The rocks below the unconformity are folded twice, while those above show no such folding. During the Late Cretaceous, Arabia was overthrust by the Samail Ophiolite and Hawasina deep-sea sedimentary rocks. Final doming occurred during the late Eocene to early Miocene. The Jabal Akhdar Dome is a textbook example of stratigraphy and structural geology development from the Cryogenian to the present. Furthermore, findings from the dome can be used as a natural laboratory and serve as an analogue for the hydrocarbon-bearing sequences in interior Oman. The two-day field trip will start at the Saiq Plateau where we will examine Cryogenian Snowball-Earth diamictites with cap carbonates, blended within the scenic landscape of Jabal Akhdar. The second day will start at a breath-taking vista point at Wadi Bani Awf. From there we will descend into the core of the Jabal Akhdar and explore the structural style of the Cryogenian and younger succession. Field Trip Information: Date: 9th – 10th April 2026 Time: 7:30am – 7pm Field Trip fee: $550 Registration Deadline: 5th March 2026 (*registration will be opening shortly) Fees Include: 1 night accommodation in a hotel Guided hiking tour through rose farms and ancient villages in Jebel Akhdar (2–3 hours) Traditional Omani lunch hosted at a local home BBQ dinner in a scenic open area at Jebel Akhdar All transportation (4x4s) Field Trip Leaders Andreas Scharf GUtech Oman Ivan Callegari GUtech Oman Wilfried Bauer GUtech Oman

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American Association of Petroleum Geologists (AAPG)
Workshop
Muscat, Oman
Monday, 6 April Wednesday, 8 April 2026, 8:00 a.m.–5:00 p.m.

The AAPG Structural Styles of the Middle East is back! This exciting and highly anticipated Geoscience Technology Workshop will take place from 6 – 8 April 2026, in Muscat, Oman. This workshop aims to explore the diverse structural styles resulting from the different deformation phases on the tectonostratigraphic framework of the Arabian Plate and adjacent regions.  

American Association of Petroleum Geologists (AAPG)
DL Abstract

Physics is an essential component of geophysics but there is much that physics cannot know or address. 

Request a visit from John Castagna!

American Association of Petroleum Geologists (AAPG)
DL Abstract

As oil and gas exploration and production occur in deeper basins and more complex geologic settings, accurate characterization and modeling of reservoirs to improve estimated ultimate recovery (EUR) prediction, optimize well placement and maximize recovery become paramount. Existing technologies for reservoir characterization and modeling have proven inadequate for delivering detailed 3D predictions of reservoir architecture, connectivity and rock quality at scales that impact subsurface flow patterns and reservoir performance. Because of the gap between the geophysical and geologic data available (seismic, well logs, cores) and the data needed to model rock heterogeneities at the reservoir scale, constraints from external analog systems are needed. Existing stratigraphic concepts and deposition models are mostly empirical and seldom provide quantitative constraints on fine-scale reservoir heterogeneity. Current reservoir modeling tools are challenged to accurately replicate complex, nonstationary, rock heterogeneity patterns that control connectivity, such as shale layers that serve as flow baffles and barriers.

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Request a visit from Tao Sun!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Around 170 million years ago, the Gulf of Mexico basin flooded catastrophically, and the pre-existing landscape, which had been a very rugged, arid, semi-desert world, was drowned beneath an inland sea of salt water. The drowned landscape was then buried under kilometers of salt, perfectly preserving the older topography. Now, with high-quality 3D seismic data, the salt appears as a transparent layer, and the details of the drowned world can be seen in exquisite detail, providing a unique snapshot of the world on the eve of the flooding event. We can map out hills and valleys, and a system of river gullies and a large, meandering river system. These rivers in turn fed into a deep central lake, whose surface was about 750m below global sea level. This new knowledge also reveals how the Louann Salt was deposited. In contrast to published models, the salt was deposited in a deep water, hypersaline sea. We can estimate the rate of deposition, and it was very fast; we believe that the entire thickness of several kilometers of salt was laid down in a few tens of thousands of years, making it possibly the fastest sustained deposition seen so far in the geological record.

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Request a visit from Frank Peel!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Subsurface risk and uncertainty are recognized as very important considerations in petroleum geoscience. And even when volume estimates are relatively accurate, the reservoir characteristics that determine well placement and performance can remain highly uncertain. In analyzing results and work practices, three aspects of uncertainty are reviewed here.

Request a visit from Kurt W. Rudolph!

American Association of Petroleum Geologists (AAPG)
DL Abstract

The Energy sector is a changing business environment. Throughout the 20th century fluctuations of oil supply and demand produced changes in the barrel price that pushed the growth or shrinkage of the industry. In this 21st century, new challenges such as diversification of the energy mix, boosting gas demand, require the exploration of critical minerals and development of new technologies as well.

Request a visit from Fernanda Raggio!

American Association of Petroleum Geologists (AAPG)
DL Abstract

Local sea-level changes are not simply a function of global ocean volumes but also the interactions between the solid Earth, the Earth’s gravitational field and the loading and unloading of ice sheets. Contrasting behaviors between Antarctica and Scotland highlight how important the geologic structure beneath the former ice sheets is in determining the interactions between ice sheets and relative sea levels.

Request a visit from Alex Simms!

American Association of Petroleum Geologists (AAPG)
DL Abstract

While there are many habitats that are associated with the deposition of organic-rich marine and lacustrine source rocks, one important pathway is linked to the onset of increased basin subsidence associated with major tectonic events. A key aspect is that this subsidence is spatially variable, with the uplift of basin flanks contemporaneous with the foundering of the basin center, resulting in a steeper basin profile.

Request a visit from Kurt W. Rudolph!

American Association of Petroleum Geologists (AAPG)
VG Abstract

Production from unconventional petroleum reservoirs includes petroleum from shale, coal, tight-sand and oil-sand. These reservoirs contain enormous quantities of oil and natural gas but pose a technology challenge to both geoscientists and engineers to produce economically on a commercial scale. These reservoirs store large volumes and are widely distributed at different stratigraphic levels and basin types, offering long-term potential for energy supply. Most of these reservoirs are low permeability and porosity that need enhancement with hydraulic fracture stimulation to maximize fluid drainage. Production from these reservoirs is increasing with continued advancement in geological characterization techniques and technology for well drilling, logging, and completion with drainage enhancement. Currently, Australia, Argentina, Canada, Egypt, USA, and Venezuela are producing natural gas from low permeability reservoirs: tight-sand, shale, and coal (CBM). Canada, Russia, USA, and Venezuela are producing heavy oil from oilsand. USA is leading the development of techniques for exploring, and technology for exploiting unconventional gas resources, which can help to develop potential gas-bearing shales of Thailand. The main focus is on source-reservoir-seal shale petroleum plays. In these tight rocks petroleum resides in the micro-pores as well as adsorbed on and in the organics. Shale has very low matrix permeability (nano-darcies) and has highly layered formations with differences in vertical and horizontal properties, vertically non-homogeneous and horizontally anisotropic with complicate natural fractures. Understanding the rocks is critical in selecting fluid drainage enhancement mechanisms; rock properties such as where shale is clay or silica rich, clay types and maturation , kerogen type and maturation, permeability, porosity, and saturation. Most of these plays require horizontal development with large numbers of wells that require an understanding of formation structure, setting and reservoir character and its lateral extension. The quality of shale-gas resources depend on thickness of net pay (>100 m), adequate porosity (>2%), high reservoir pressure (ideally overpressure), high thermal maturity (>1.5% Ro), high organic richness (>2% TOC), low in clay (<50%), high in brittle minerals (quartz, carbonates, feldspars), and favourable in-situ stress. During the past decade, unconventional shale and tight-sand gas plays have become an important supply of natural gas in the US, and now in shale oil as well. As a consequence, interest to assess and explore these plays is rapidly spreading worldwide. The high production potential of shale petroleum resources has contributed to a comparably favourable outlook for increased future petroleum supplies globally. Application of 2D and 3D seismic for defining reservoirs and micro seismic for monitoring fracturing, measuring rock properties downhole (borehole imaging) and in laboratory (mineralogy, porosity, permeability), horizontal drilling (downhole GPS), and hydraulic fracture stimulation (cross-linked gel, slick-water, nitrogen or nitrogen foam) is key in improving production from these huge resources with low productivity factors.

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Request a visit from Ameed Ghori!

American Association of Petroleum Geologists (AAPG)
VG Abstract

The carbonate sequences that were deposited in the now exhumed Tethyan Ocean influence many aspects of our lives today, either by supplying the energy that warms our homes and the fuel that powers our cars or providing the stunning landscapes for both winter and summer vacations. They also represent some of the most intensely studied rock formations in the world and have provided geoscientists with a fascinating insight into the turbulent nature of 250 Million years of Earth’s history. By combining studies from the full range of geoscience disciplines this presentation will trace the development of these carbonate sequences from their initial formation on the margins of large ancient continental masses to their present day locations in and around the Greater Mediterranean and Near East region. The first order control on growth patterns and carbonate platform development by the regional plate-tectonic setting, underlying basin architecture and fluctuations in sea level will be illustrated. The organisms that contribute to sequence development will be revealed to be treasure troves of forensic information. Finally, these rock sequences will be shown to contain all the ingredients necessary to form and retain hydrocarbons and the manner in which major post-depositional tectonic events led to the formation of some of the largest hydrocarbon accumulations in the world will be demonstrated.

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Request a visit from Keith Gerdes!

American Association of Petroleum Geologists (AAPG)
DL Abstract

President Biden has laid out a bold and ambitious goal of achieving net-zero carbon emissions in the United States by 2050.  The pathway to that target includes cutting total greenhouse gas emissions in half by 2030 and eliminating them entirely from the nation’s electricity sector by 2035. The Office of Fossil Energy and Carbon Management will play an important role in the transition to net-zero carbon emissions by reducing the environmental impacts of fossil energy production and use – and helping decarbonize other hard-to abate sectors.

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Request a visit from Jennifer Wilcox!

American Association of Petroleum Geologists (AAPG)

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