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Sedimentology and Stratigraphy

Middle East Blog

Mark your calendars! Don't miss out on this exciting GTW, which builds on the success of the first Carbonate Reservoirs of the Middle East GTW held in Abu Dhabi, UAE in 2015..

American Association of Petroleum Geologists (AAPG)
Explorer Historical Highlights

A few months after the founding of AAPG in early 1917, the first description of the Wolfcamp Formation was published in the University of Texas Bulletin No. 1753 titled “Notes on the Geology of the Glass Mountains” by J. A. Udden, on Sept. 20, 1917.

American Association of Petroleum Geologists (AAPG)
Explorer Emphasis Article

The Next 100 Years: Data management is a crucial component of oil exploration. What does the century ahead look like for Big Data in the oil field?

American Association of Petroleum Geologists (AAPG)
Middle East Blog

The GEO 2018 committee welcomes your abstracts for oral and poster presentations at the 13th Middle Geosciences Conference and Exhibition (GEO 2018) which will take place from 5 — 8 March in Bahrain. Submit today and join the largest gathering of geoscience professionals in the Middle East.

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)
Explorer Emphasis Article

Last year, the extraordinarily high quality of the technical program was the talk of the AAPG Annual Convention and Exhibition in Calgary, and this was at an ACE with plenty of high points to talk about. The technical program for the 2017 ACE in Houston promises to be even better than last year’s.

American Association of Petroleum Geologists (AAPG)
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)
Search and Discovery Article

The driving forces for conventional accumulations (structural or stratigraphic traps) are Forces of Buoyancy which are due to differences in densities of hydrocarbons and water. In contrast, the driving forces for unconventional tight accumulations are Forces of Expulsion which are produced by high pressures. That is an enormous difference and creates unconventional petroleum systems that are characterized by very different and distinctive characteristics. The Force of Expulsion pressures are created by the significant increase in volume when any of the three main kerogen types are converted to hydrocarbons. At those conversion times in the burial history, the rocks are already sufficiently tight so the large volumes of generated hydrocarbons cannot efficiently escape through the existing tight pore system, thus creating a permeability bottleneck that produces an overpressured compartment over a large area corresponding to the proper thermal oil and gas maturities for that basin. The forces initially created in these source rocks can only go limited distances into adjacent tight reservoirs (clastics or carbonates) above or below the source. The exact distance will vary depending on the pressure increase, matrix permeability, and fractures of that specific tight reservoir system. In general, the distances are small, in the orders of 10s to 100s of feet for oil and larger for more mobile gas systems. Those exact distance numbers are subject to ongoing investigations.   A plot of the pressure data versus elevation for a given formation is critical in determining whether an accumulation is conventional or unconventional. Conventional accumulations will have hydrocarbon columns of 10s to 100s of feet with the pressure in the hydrocarbons and that in the water equal at the bottom of the accumulation (at the HC-water contact). In contrast, the unconventional accumulations will show HC column heights of 1000s of feet with the pressure in the hydrocarbon phase and the water phase being the same at the top of the accumulation (at the updip transition zone). Those significant differences are critical for understanding and differentiating these two play types. Because the system is a pore throat bottleneck with very little or minimum lateral migration, the type of hydrocarbon s are closely tied to the thermal maturity required to generate those hydrocarbons. Thus the play concept begins with two important geochemical considerations: (1) where are the source rocks and what are the kerogen types and organic richness (TOC), and (2 ) where are they mature in the basin for oil, condensate, and gas in the basin. These parameters will very quickly define the fairway for the play. Then one has to add the critical information on the reservoirs themselves: composition (brittleness), thickness, and reservoir quality (matrix porosity and permeability). In summary, these tight unconventional petroleum systems (1) are dynamic , and (2) create a regionally inverted petroleum system with water over oil over condensate over gas for source rocks wit h Type I or II kerogen types.

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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)
Explorer Emphasis Article

The eastern Mediterranean Sea could become the hottest offshore play in the Middle East area, depending on the outcome of a key exploration attempt later this year.

American Association of Petroleum Geologists (AAPG)
Field Seminar
Naples, Italy
Friday, 24 June Saturday, 25 June 2022, 8:00 a.m.–5:00 p.m.

Field Trip Leaders: Jean Borgomano – CEREGE, Aix-Marseille Université, France Michele Morsilli – University of Ferrara, Italy Themes The Gargano Promontory (southern Italy) offers the opportunity to investigate a complete carbonate facies transect from inner platform to basin and to reconstruct the various events that shaped and controlled the evolution of the Apulia Carbonate Platform during the Cretaceous and Paleogene. This area can be considered a wonderful outcrop analog to better understand and visualize facies, depositional geometries, stratigraphic relationships and to compare them with other carbonate platforms. The exposed carbonate rocks show well-preserved original reservoir properties and form relevant analogues of subsurface reservoirs located in different structural settings; e.g. inner platform palaeokarst (Ombrina Mare, Rospo Mare oil fields), subthrust setting (Monte Alpi, Tempa Rossa), slope, base-of-slope resedimented carbonate facies (Elsa, Miglianico, Aquila, Rovesti), as well as relevant for the comparison with the specular Adriatic Carbonate Platform (AdCP) or other Tethyan carbonate systems. Main goals of this field trip are the observation of the facies and stratigraphic architecture of the inner platform and of slope and base-of-slope units deposited during the Early - Late Cretaceous and Eocene, as well as the carbonate production and exporting/resedimentation processes. The Apulia Carbonate Platform represents a well-known case study of a carbonate platform with different evolution through time. Facies distribution from inner platform to base-of-slope, stratigraphic architecture and depositional geometries, together with retreat and drowning of the platform or margin collapses, and seismic-scale outcrops, in a relatively poorly deformed context, constitute a text book examples of a Cretaceous Carbonate System. Itinerary and Stops Day 1 Naples (or Bari airport) to Apricena by bus (travel about 3 h) Stop 1.1 - Apricena quarries district: stop on peritidal cycles of Lower Cretaceous, fractured and karst reservoir (outcrop analog of the Rospo Mare oil field). Lunch Stop 1.2 - Belvedere di Ruggiano: stop on scalloped/faulted platform margin of mid-Cretaceous and base of slope to basin facies associations. Night in Monte Sant’Angelo Day 2 Stop 2.1 ft-e: slope to basin facies of the Lower Cretaceous and facies observation of the resedimented succession of the Upper Cretaceous. Lunch Stop 2.2 Monte Sant’Angelo to Manfredonia road – Upper Cretaceous slope to base of slope facies and architecture of the systems. Stop 2.3 (optional) - Monte Saraceno-Mattinata: panoramic view of the Upper Jurassic-Lower Cretaceous sequence and Valanginian retreating/drowning of the Apulia Platform and depositional geometries of the Eocene clinoforms. End of the Excursion (travel to Naples or Bari airport)

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American Association of Petroleum Geologists (AAPG)
Field Seminar
Naples, Italy
Tuesday, 21 June 2022, 8:00 a.m.–5:00 p.m.

Field Trip Leaders: Alessandro Iannace Stefano Tavani Mariano Parente (University of Naples Federico II, Italy) Themes The Cretaceous platform carbonates of the Sorrento Peninsula offer wonderful outcrop analogues for the reservoirs of the Monte Alpi and Tempa Rossa oil fields of subsurface Basilicata and for fractured carbonate reservoirs of other Tethyan carbonate systems. During this 1-day field trip we will see how the facies, diagenetic characters and stacking patterns of cyclical Barremian-Albian inner platform carbonates controls mechanical stratigraphy and fracture distribution. We will look at the fracture network at different scales, from stratabound fractures to reservoir-scale fracture corridors, combining panoramic observations of subvertical cliffs of the Mt. Faito ridge, exposing a >300m thick stratigraphic interval, with detailed observations of the same beds along roadcuts. Then, we will move to a road cut near Positano where we will observe a small-scale intraplatform basin, developed in Aptian-Albian carbonates, focusing on soft-sediment deformation, organic-rich dolostones, fault-zone architecture and breccia bodies. Itinerary and Stops Transfer from Naples to Mt Faito by minibuses (about 1h drive) Stop 1 – Ticciano village: general introduction to the geology of the southern Apennines and to the Apennine Carbonate Platform; panorama of the Mesozoic platform carbonates of the Monte Faito ridge Stop 2 – Croce dell’Eremita roadcut: facies and fracture distribution of Barremian-Albian inner platform interbedded dolostones-limestones Lunch Stop 3 – Santa Maria del Castello: panoramic view of Monte Conocchia cliff: distribution and arrest of vertical through-going joints and fracture corridors in a seismic scale carbonate platform exposure Stop 4 – roadcut north of Positano: middle Cretaceous synsedimentary tectonics, soft sediment deformation, organic-rich dolostones and breccia bodies in a small intraplatform trough. Driving back to Naples (about 90min drive)

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American Association of Petroleum Geologists (AAPG)
Workshop
Virtual Workshop
Tuesday, 8 March Wednesday, 9 March 2022, 8:00 a.m.–5:00 p.m.

This two-day virtual conference aims to bring together industrial and academic persons to present, explore and develop approaches that will benefit both sectors in the future. The virtual conference will focus on current techniques, the challenges and future solutions in understanding the Triassic stratigraphy of the North Sea, Norwegian Sea, West of Shetland, Atlantic margins, and northern Europe.

American Association of Petroleum Geologists (AAPG)
Workshop
Naples, Italy
Wednesday, 22 June Thursday, 23 June 2022, 8:00 a.m.–5:00 p.m.

Modelling carbonate sequences and reservoirs has always been a challenging task. Carbonate rocks are generated and subsequently modified by a large variety of biological, physical and chemical processes that start at the time of deposition and end today. To unravel the geological evolution and history of carbonate sequences is fundamental not only for understanding their hydrocarbons potential but also for their role as potential reservoirs for renewable energy (geothermal) or geological gas storage (CO2 and hydrogen). Several science disciplines are often involved to fully understand the characteristics of carbonate rocks and old approaches and new technologies and tools are nowadays applied in these types of sequences. The objective of this meeting is to allow scientists and engineers working on carbonate rocks in academia and industry to share their most recent experience, work, approaches and use of innovative technologies to increase the understanding of the very complex world of carbonates.

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American Association of Petroleum Geologists (AAPG)
Field Seminar
Barcelona, Spain
Wednesday, 30 March Thursday, 31 March 2022, 8:00 a.m.–5:00 p.m.

Trip leader(s): Josep Anton Muñoz, Pablo Granado and Eduard Roca Limit: 20 Participants The aim of this 2-day field trip is the recognition of the key structural features of a fold and thrust belt detached on salt that has resulted from the inversion of a previous passive margin. To achieve this objective, some of the key and most spectacular localities of the southern Pyrenees have been selected along the ECORS-Pyrenees transect. This is a reference cross-section provided that for many years a huge amount of geological and geophysical data sets has been collected and integrating into a kinematic model of the South-Pyrenean fold and thrust belt. Subsurface data (well logs and seismic sections) will be combined with field observations. One of the main characteristics of the southern Pyrenees is the preservation of the synorogenic sediments since the earlier stages of deformation, which not only provide time constraints but also allow us discussion of kinematics of fault-related folds and thrust systems. Finally, the mild contractional deformation permits deciphering the initial geometry of the rift system and the salt structures that configure the structural grain of the passive margin before the inversion, allowing discussion of the role that these structures play during the fold and thrust belt development. Itinerary: (day by day details of the trip) Day 1 Stop 1.1: The South-Pyrenean thrust front. Sant Llorenç de Montgai Structure of a frontal thrust system and related unconformities. Out of sequence thrusts and synorogenic sediments. The frontal thrust system of the South-central Pyrenees has been detached into the Triassic evaporites and involves a thin Mesozoic succession. It is characterized by an emergent thrust system during the sedimentation of upper Eocene and lower Oligocene continental sediments. Frontal thrusts were progressively buried by conglomerates, triggering a break-back thrusting sequence and the development of out-of-sequence thrusts bringing together strongly different Mesozoic successions, such as the Montroig thrust in the picture. Stop 1.2: The Ager basin and the Montsec thrust sheet. Fontllonga The Ager basin in the footwall of the Montsec thrust. The Montsec thrust sheet developed from the Paleocene to the Early Eocene as recorded by continental to shallow marine sediments deposited in its footwall (Ager basin) as well as in the Tremp-Graus piggy-back basin. The lower Eocene sediments of these basins grade westward into the slope succession filling the Ainsa basin at the footwall of the Montsec thrust. Stop 1.3: The frontal structure of the Montsec thrust sheet. Ametlla (optional: Montrebei) Fault-propagation fold related with the inversion of Early Cretaceous extensional faults and growth deltaic sediments in the footwall syncline. The Montsec thrust sheet involves the northern part of the Upper Cretaceous foreland basin characterised by a strong subsident turbiditic trough at the footwall of the Bóixols thrust. These turbidites grade southward into a carbonatic platform that constitutes the backbone of the Montsec Range (main ridge and cliff of the pictures). Underneath the Upper Cretaceous carbonates, some Early Cretaceous extensional faults are preserved in the hanging wall of the Montsec thrust, but others have controlled the development of a hanging wall frontal anticline. The geometry of this anticline as well as the structure of the growth sediments in the footwall Ager syncline are visible in the field. The subthrust geometry will be discussed integrating surface observations and the available seismic and well data. Overnight in Tremp Day 2 Stop 2.1: The Sant Corneli-Bóixols anticline Inversion of the rift margin The Sant Corneli-Bóixols anticline is the most prominent frontal structure of the Bóixols thrust sheet in the central Pyrenees. This fold trends east–west and crops out for greater than 40 km along strike. The Sant Corneli-Bóixols anticline involves a thick Mesozoic succession detached on top of Triassic evaporites. The prefolding sequence consists of up to 5 km of prerift, synrift, and postrift carbonates ranging in age from Jurassic to Upper Cretaceous. Synfolding Upper Cretaceous sediments start with the upper Santonian carbonates and continue with a succession of Campanian and Maastrichtian marls and turbidites. The Sant Corneli–Bóixols anticline is an example of an inversion fold developed along the rift margin of the Lower Cretaceous basin. Its geometry is related with the inverted extensional system. In particular, the three-dimensional geometry, including the saddles between culminations, is inherited from the previous transfer faults of the segmented rift margin. Available seismic data and 3 exploratory wells constrain the geometry at depth. Stop 2.2: The synororgenic Paleogene conglomerates Inverted Lower Cretaceous basin and Eocene-Oligocene synorogenic conglomerates at Collegats gorge. Stop 2.3 (optional): The Sopeira and Aulet minibasins. Sopeira Minibasins developed by extensional collapse and salt evacuation during the thermal subsidence at the southern Pyrenean rift margin. Inversion of these mini-basins at the early stages of Pyrenean contractional deformation during Late Cretaceous. Additional logistic information Transportation Transportation will be with a small bus, assisted by minivans to have access to some of the outcrops. Physical demand, equipment and safety This is an easy field trip with very easy and limited hikes to get to the outcrops. Outcrops will be from main sealed roads. Safety vests will be available, to be used by everybody of the group wherever required and asked to. There will be First Aid Kits available in each car during fieldwork. Climate The climate during mid-end November in the fieldwork area can be cold and rainy, although dry and sunny days may occur as well. The temperature for November in Tremp can range between 30C and 170C. Participants should be prepared in case we should encounter bad weather and you should bring warm and waterproof clothes and suitable hiking boots. -->

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American Association of Petroleum Geologists (AAPG)
Workshop
Lisbon, Portugal
Wednesday, 18 May Thursday, 19 May 2022, 8:00 a.m.–5:00 p.m.

This 2-day conference brings together diverse experts working on modern and ancient turbidite, MTDs, contourite and hybrid/mixed systems in order to improve the present-day knowledge, models and predictive power.

American Association of Petroleum Geologists (AAPG)
Field Seminar
Lisbon, Portugal
Monday, 16 May Tuesday, 17 May 2022, 8:00 a.m.–5:00 p.m.

Come along on this 2-day field seminar and tour outcrops in the Serra de Montejunto, just north of Lisbon and on the coast from Porto Novo to Paimogo. Instructors: Ricardo Pereira, (PARTEX Oil and Gas & Instituto Dom Luiz) Gil Machado (ChronSurveys Lda & Instituto Dom Luiz) Fees: To be determined Includes: Hotel Ground Transporation Snacks and Refreshments Lunch and Dinner Guidebook Departure Time/Location 16 May 2020 8:30am SANA Metropolitan Hotel Note:Transportation to start point is not included in the costs of this trip. Please bring clothing for hot day time temperatures (sun hat/ sun glasses/ sun cream etc.). Participants must wear suitable and comfortable light trekking shoes. Aims To gain or increase an understanding of the tectono-sedimentary processes of continental extension and rifting supported by outcrop observations, with focus on deep-depositional marine systems. Discuss implications for prospective petroleum systems. Promote debate and nourish new insights between attendants. About the Field Trip The Lusitanian Basin records the proximal events of syn- to post rift evolution of the hyper-extended West Iberian Margin, showing some outstanding examples of the combined tectono-stratigraphic depositional systems. Here, the Late Jurassic reveals diverse aspects of mixed marine depositional systems including not only submarine fans and turbidites, but also the build-up of carbonate reefs and shoreface to fluvial clastic sequences. Throughout the fieldtrip the different depositional aspects can be observed in detail to demonstrate how such depositional systems can vary in time and space. Observation of these outcrops allows a better understanding on how deep-water depositional systems can change within a sub-basin and help improving the understanding of reservoir properties. Itinerary Day 1 (16th May 2022) Stop # Location Relevant Aspects 1 Vila Franca de Xira Intro-Overview 2 Castanheira Coarse grain proximal depositional systems; Fault slope deposits 3 Arruda Marine shales and interbedded clastic deposits 4 Ota Late Jurassic marine reefs 5 Montejunto-Vila Verde Marine shales and interbedded clastic deposits 6 Wrap-up at the Hotel   Day 2 (17th May 2022) 1 Consolação-São Bernardino Shaly marine deposits of the Abadia Fm. (Kimm.) 2 Paimogo Shoreface to fluvial deposits Late Jurassic 3 Porto Novo Shoreface to fluvial deposits Late Jurassic 4 Santa Cruz Late Jurassic turbidites

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American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Monday, 19 October 2020, 12:00 p.m.–1:30 p.m.

In this webinar, Stephen Ehrenberg will present a review of the various processes that interact to determine the wide variations in porosity found in carbonate strata containing petroleum reserves. Presentation is via Zoom on Monday 19 October at 12:00 London time.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Thursday, 12 November 2020, 5:00 p.m.–6:00 p.m.

Contourites have come of age – both scientifically and economically. These deepwater sedimentary systems, driven by long-slope bottom-current processes, are a fundamental component of many continental margin successions. They are inter-bedded with and interact with down-slope systems, pelagic systems, and deep tidal processes. The contourite play clearly works – now we need to make it a primary target in future deepwater exploration.

American Association of Petroleum Geologists (AAPG)
VG Abstract

This lecture will discuss the differences between carbonates and siliciclastics from their chemical composition through their distributions in time and space. Building on these fundamental differences, we will explore the challenges carbonates pose to petroleum geologists in terms of seismic interpretation, reservoir quality prediction, field development, etc. Peppered with humorous personal stories, still raging academic debates, and the heartfelt frustrations of real industry professionals, the aim is to inspire students and young professionals to rise to the occasion and embrace the reservoir rocks that petroleum geologists love to hate.

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Request a visit from Noelle Joy Purcell!

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)
VG Abstract

The following short course option was developed for geology and geophysics students that have not had much exposure to how geoscience is applied in industry. It can be tailored for undergraduate juniors and seniors or graduate students. The agenda can be modified to meet specific needs and time constraints. Contact the presenter to discuss options.

Request a visit from Fred Schroeder!

American Association of Petroleum Geologists (AAPG)

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