Search and Discovery Article

The assessment of the natural temporal variability of source rock units is critical for the understanding of petroleum systems as changes in mineral matrix, organic matter (OM) concentration, and composition can significantly affect expulsion efficiency, primary and secondary migration processes, hydrocarbon quality as well as oil source rock correlation. Already small-scaled fluctuations within sediment successions can critically influence migration efficiency. High-resolution investigation of a well-preserved Lower Jurassic drill core (Toarcian Posidonia Shale) revealed seven discrete and systematic intervals of deviating source rock quality. These were composed of homogenized, non-laminated marls of light grey color, opposed to laminated dark grey background sedimentation. Both lithotypes differentiate not only in mineral composition, but particularly in OM content and quality. An average TOC content of app. 3.9 wt.% reached by the grey marl, is faced by an average TOC content of app. 7.8 wt.% measured for the laminated dark grey marls. Average hydrogen index for grey non-laminated marls was app. 550 mg HC/g TOC, whereas much higher source rock quality with 780 mg HC/g TOC was attained in the dark laminated marls. The marls lower OM concentration and inferior OM quality generates important domains for preferential migration of products, originated from the dark grey layers, or hydrocarbon cluster in case of limited migration into adjacent reservoirs. To assess the potential for preferential intake of hydrocarbons by the coarser-grained light marls and their qualification as migration avenues, artificial maturation experiments were performed with both lithotypes. Hydrocarbon generation was simulated by hydrous pyrolysis in two successive temperature steps 330 °C and 360 °C, covering an early maturity stage, as well as the end of the oil window. Both lithologies show striking differences, not only for the extract yield, but also for the timing of generation. OM quality differences were reflected by variable n-alkane distributions and molecular maturity parameters. High-resolution continuous data produced by non-destructive techniques allows to draw conclusions on i) source rock potential, ii) expulsion and migration processes , and iii) on prediction of petroleum accumulation within the sediment succession. High-resolution investigation in combination with artificial maturation experiments represent an easy-to-use tool in petroleum system analysis.

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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 European Regional Conference, “Hydrocarbons in the Mediterranean: revisiting mature plays and understanding new and emerging ideas,” will be held Jan. 18-19 in Larnaca, Cyprus.

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)
Learn! Blog

The Petroleum Geochemistry Toolkit for Petroleum Exploration and Development 2-day course, is designed to provide the geologist, geophysicist, and engineer with a general understanding of applied petroleum geochemistry and how it can be used in petroleum exploration and development. The petroleum systems analysis examines geological elements and processes that are essential for the petroleum accumulation.

American Association of Petroleum Geologists (AAPG)
Learn! Blog

Where is the oil? How much is there? and What is the best strategy for recovery? These are a few of the questions that we'll answer at the Making Money with Mature Fields - Geosciences Technology Workshop, October 5-6, 2016, Houston, TX. The goal of this workshop is to review mature fields and to identify the amount and nature of oil that can be recovered, and to evaluate competing strategies for economically producing the remaining reserves. In addition to looking closely at fields, we will review new and improved technologies that may help revitalize reservoirs and overcome problems such as low pressure, paraffin, corrosion, and more.

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American Association of Petroleum Geologists (AAPG)
Learn! Blog

Jointly organized by the Society of Petroleum Engineers (SPE), the American Association of Petroleum Geologists (AAPG) and the Society of Exploration Geophysicists (SEG), URTeC connects the key technical and business professionals deciding where, how and when plays will be developed and wells drilled every day. It’s the only event leveraging expertise from all technical backgrounds and focusing on the asset team approach to successful field development. URTeC Delivers... One of the industry's most interactive networking forums for companies across all segments of the unconventional market An unmatched, integrated audience of qualified decision makers with whom to build new business relationships with and generate leads A platform for showcasing your products, technologies and solutions with almost 150 exhibiting companies A superior quality science and technology event attended by 3,500 colleagues on average

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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)
Explorer Emphasis Article

The 2016 Halbouty Lecture series presentation by Tim Dodson, executive vice president of Statoil ASA, will focus on Statoil’s high impact Bay du Nord discovery in the deepwater Flemish Pass Basin in 2013.

American Association of Petroleum Geologists (AAPG)
Workshop
Virtual Workshop
Monday, 18 October Wednesday, 20 October 2021, 10:30 a.m.–6:00 p.m.

Join us virtually in this event that was due to be hosted in Salzburg, the “castle of salt” and cradle of Mozart and Doppler. We aim to host an interactive meeting aimed at bringing together different perspectives in the science of evaporite basins: from their formation to their deformation, from description and characterization to modelling. Exploratory success in evaporite-rich basins worldwide has depended on the role of evaporites as a deformable substrate, as a seal, or even as a good thermal conductor. The aim of this workshop is to improve our understanding and predictive ability by addressing evaporite systems in an integrated manner, all the way from precipitation to structuration, and exploring the multiple properties of evaporite sequences. This will be done via technical sessions, keynote speaker presentations, panel sessions and more!

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American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 26 September 2013, 12:00 a.m.–12:00 a.m.

The presentation will discuss key reservoir information and how to develop a predictive pressure model.

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Friday, 20 January 2012, 12:00 a.m.–12:00 a.m.

The Eagle Ford Shale in South Texas is one of the more exciting shale plays in the United States at the current time.

American Association of Petroleum Geologists (AAPG)
Online Certificate Course
Tuesday, 1 January 2013, 12:00 a.m.–1:00 a.m.

This course introduces the learner to the fundamentals of shale gas, including current theories that explain its origin, and how to determine which reservoirs are commercially viable.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Tuesday, 30 June 2020, 1:00 p.m.–2:00 p.m.

Visiting Geoscientist Juan Pablo Lovecchio reviews general aspects of rifting, rifts and passive margin formation and evolution through time, as well as elements of petroleum system development.

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 9 December 2010, 12:00 a.m.–12:00 a.m.

The Mississippian-Devonian Bakken Petroleum System of the Williston Basin is characterized by low-porosity and permeability reservoirs, organic-rich source rocks, and regional hydrocarbon charge.

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 17 March 2011, 12:00 a.m.–12:00 a.m.

This e-symposium will provide information on which tools, processes, and procedures all geoscientists, engineers, and technical professionals working in shale plays need to understand and implement.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Thursday, 25 June 2020, 8:00 a.m.–9:00 a.m.

Panelists will discuss current unconventional resource activities in North America, including key plays that remain competitive and potential for future growth. They also will address the key challenges for unconventional resources to stay competitive in the global market: maintaining cashflow, reducing expenditures, improving capital and production efficiencies and managing resources. Virtual Forum to be presented via Zoom.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Thursday, 4 June 2020, 3:00 p.m.–4:00 p.m.

Salt welds form due to salt thinning by mechanical (e.g., salt-flow) and/or chemical (e.g., salt-dissolution) processes. This webinar explores how we use 3-D seismic reflection, borehole, and biostratigraphic data to constrain the thickness and composition of salt welds, and to test the predictions of analytical models for salt welding.

American Association of Petroleum Geologists (AAPG)
Webinar
Virtual Webinar
Thursday, 27 August 2020, 3:00 p.m.–4:00 p.m.

There are over 300 known active onshore mud volcanoes globally, and many more offshore. Mud volcanoes are subsurface fluid escape features in which high pore pressures drive fluids, gases, and subsurface sediments to the surface. This talk will summarize mud volcanoes around the world and examine mud volcano plumbing systems and their link to petroleum systems.

American Association of Petroleum Geologists (AAPG)
Online e-Symposium
Thursday, 13 December 2012, 12:00 a.m.–12:00 a.m.

The course will review core data, petrophysical comparisons, rock physics modeling (including pseudo logs and mechanical properties).

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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American Association of Petroleum Geologists (AAPG)

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