Search and Discovery Article

Rock-Eval hydrogen index (HI) is often used to compare relative maturities of a source horizon across a basin. Usually, there are several measurements from the source horizon at a single well, and the mean hydrogen index is calculated, or the S2 is plotted against TOC. The slope of the best fit line through that data is used as the representative HI for that well (sometimes referred to as the ‘slope HI ’ methodology). There is a potential flaw in both these methodologies; however, that renders the calculated HI as misleading if the source horizon being examined is not relatively uniform in source quality, vertically in the stratigraphic column. From a geologic perspective, it would be unusual for the source rock quality not to vary vertically in the stratigraphic column. Organic matter input, preservation, dilution, and sediment accumulation rate typically vary in many depositional environments over the millions of years required to create a thick source rock package. Nevertheless, there are source rocks which do display remarkable source-quality uniformity from top to bottom of the stratigraphic package. We have examined source rocks from several basins where the source quality is relatively uniform over the stratigraphic column, and source rocks where the source quality varies greatly over the stratigraphic column. Methodologies to assess hydrogen index at specific wells for the se two scenarios differ. Most geoscientists may not be familiar with why a single technique is not suitable for both these scenarios, or how to correctly use hydrogen index as a relative maturation proxy in the case where source rock quality is not uniform. We will demonstrate how to determine if your source rock quality is uniform or varied relative to HI over the stratigraphic column, and how to assign a hydrogen index to the different source facies when that source rock quality is not uniform. Further we will illustrate how to estimate the original hydrogen index of the different source facies and assign each a transformation ratio. The transformation ratio is a better proxy for relative maturity, since different source facies may have different present-day hydrogen indices, but their present-day transformation ratio should be quite similar.

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American Association of Petroleum Geologists (AAPG)
Explorer Article

The AAPG Annual Convention and Exhibition will feature a variety of field trips that will bookend the meeting, spanning from March 26 to April 8.

American Association of Petroleum Geologists (AAPG)
Europe Blog

Sign up for your place at this two-day Geosciences Technology Workshop (GTW) hosted by AAPG Europe at Vilnius University in the heart of the Lithuanian capital. This workshop will focus on Hydrocarbon Exploration in Lithuania and the Baltic Region and will include 12 technical themes which have been designed to help launch perspectives for increased exploration in this region.

American Association of Petroleum Geologists (AAPG)
Europe Blog

The call for abstracts deadline is quickly approaching! Submit yours by 18 September 2016 to take part in the first Geosciences Technology Workshop (GTW) ever held in Lithuania. The workshop will cover everything from European basin modelling to carbonate sedimentology and offshore developments in the Baltic Sea.

American Association of Petroleum Geologists (AAPG)
Africa Blog

Enhance your skills with this AAPG short course on Sequence Stratigraphy designed for geoscientists, geophysicists, biostratigraphers & engineers needing a fundamental understanding of the principles and applications of sequence stratigraphy.  

American Association of Petroleum Geologists (AAPG)
Learn! Blog

Come for the GTW 'Making Money with Mature Fields', and stay for a short course; either 'The Petroleum Geochemistry Toolkit for Petroleum Exploration and Development' or 'Carbonate Depositional Systems'.  All three will explore new and innovative technologies and ideas to lend increased business opportunities now and into the future.

American Association of Petroleum Geologists (AAPG)
Learn! Blog

AAPG is excited about presenting THREE Short Courses in four days! Basic Seismic Interpretation   17-18 May 2016 'Old' (pre-1958) Electric Logs: A Quick Review 19 May 2016 Quick Guide to Carbonate Well Log Analysis   20 May 2016

American Association of Petroleum Geologists (AAPG)
Explorer Director’s Corner

Have you made plans to attend ACE this year? AAPG’s 2016 Annual Convention and Exhibition (ACE) is a dedicated opportunity for our members and other professionals to get together.

American Association of Petroleum Geologists (AAPG)
Middle East Blog

This is your last chance to register for the Source Rocks of the Middle East GTW, taking place in Abu Dhabi, UAE on 25-26 January. Do not miss out this exciting workshop!

American Association of Petroleum Geologists (AAPG)
Latin America Blog

Looking for hassle free, cost-effective ways to keep your employees and your company competitive during the industry downturn? AAPG can provide you with customized in-house courses offered at reasonable rates.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Tuesday, 9 June 2020, 4:00 p.m.–5:00 p.m.

Visiting Geoscientist Susan Morrice shares her personal experience and insight in this talk about opportunities for geoscientists. “Geoscientists have advantages ... They are Time Travellers and have open minds. Bringing this creativity and innovation to your company or starting your own! Challenging times bring silver linings!”

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 24 October 2013, 12:00 a.m.–12:00 a.m.

This e-symposium will be introducing signal processing techniques as a means to maximize extracting geomechanical data from petrophysical logs.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Thursday, 3 December 2020, 11:00 a.m.–12:00 p.m.

Patawarta Diapir, approximately 2-6km2 located in the Central Flinders Ranges, South Australia, has been interpreted as a single allochthonous salt sheet containing Tonian-aged igneous and layered evaporite sedimentary intrasalt inclusions derived from the Callanna Group. In this webinar, Rachelle Kernen describes the diapir as five primarily silty limestone inclusions (0.5-2km2), re-interpreted as Ediacaran-aged Wonoka Formation and Patsy Hill member of the Bonney Sandstone (Wilpena Group). Webinar presented Thursday 3 December 2020 at 11:00 SGT (GMT+8) Singapore time

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American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 10 May 2012, 12:00 a.m.–12:00 a.m.

Recognition and Correlation of the Eagle Ford, Austin Formations in South Texas can be enhanced with High Resolution Biostratigraphy, fossil abundance peaks and Maximum Flooding Surfaces correlated to Upper Cretaceous sequence stratigraphic cycle chart after Gradstein, 2010.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Thursday, 2 July 2020, 4:00 p.m.–5:00 p.m.

Presented by Kevin C. Hill, Associate Professor, University of Melbourne Gravity modelling of Australia's southern margin reveals that the initial rift with Antarctica was beneath the current Ceduna Delta. A regional, high-quality seismic traverse from the coast to oceanic crust across the Bight Basin has been assembled and interpreted in detail, then balanced, restored, decompacted, and replaced at paleo-water depths. The Late Cretaceous Ceduna Delta developed above a Late Jurassic-Early Cretaceous rift basin in three stages punctuated by significant pulses of uplift and erosion across areas >100 km wide and with up to 1 km of erosion. The Cenomanian White Pointer delta prograded into deepening water and hence underwent gravitational collapse. This was terminated in the Santonian when the Antarctic margin was pulled out from below, thus supplying heat to a remnant thicker outer margin crust, causing doming and erosion. Importantly, this established the saucer-shaped geometry of the Ceduna Delta that persisted throughout its development, so that any hydrocarbons generated in the southern half of the basin would have migrated towards this outer margin high. The Tiger Formation was deposited in shallow water in a full rift basin prior to breakup, which was followed by regional thermal subsidence. The Hammerhead delta developed on the newly formed passive margin but was terminated by another pulse of uplift and erosion, perhaps associated with a change in plate motion at the end of the Cretaceous. The finite element modelling of this proposed tectonic evolution will test its validity and predict hydrocarbon generation and migration through time.

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American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Wednesday, 5 March 2014, 12:00 a.m.–12:00 a.m.

Explore three of the great wonders of the geological world. Take a guided tour of classic geological sites on the Colorado Plateau.

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 10 November 2011, 12:00 a.m.–12:00 a.m.

This work investigates how heterogeneity can be defined and how we can quantify this term by describing a range of statistical heterogeneity (e.g. coefficient of variation and the Lorenz coefficient).

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 7 November 2013, 12:00 a.m.–12:00 a.m.

This e-symposium presentation places the interpretation of deep-water turbidites discernible in 3-D seismic inversion data within a geological context.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Tuesday, 5 May 2020, 12:00 p.m.–1:00 p.m.

Sequence stratigraphy is a method for stratigraphic interpretation, pioneered by Vail and colleagues in the mid 70’s, which explains the complex geometries that sediments create as they fill accommodation in response to changes in rates of sedimentation, subsidence, uplift and eustasy. This method was developed based on observations and concepts developed as early as in the 1800’s. Based on this strong scientific foundation, pioneer work from Caster, Sloss, Wheeler, Campbell, and Asquith established the basis for the methodology. These researchers established a new way to correlate stratigraphic units, demonstrating the time-transgressive nature of lithostratigraphic formations.

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American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 7 June 2012, 12:00 a.m.–12:00 a.m.

Unger Field, discovered in1955, has produced 8.6 million barrels of oil from a thinly (several ft) bedded, locally cherty dolomite containing vuggy and intercrystalline porosity.

American Association of Petroleum Geologists (AAPG)
DL Abstract

Engineering of wind farms, development of carbon sequestration projects in shelfal waters, the proliferation of communication cables that connect the world, all of these things suggest that it is time to re-examine what we know about shelf processes both updip-to-downdip and along shoreline, and the influence of shelf processes on erosion and transport of sediments.

Request a visit from Lesli Wood!

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

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)

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