Home

Structure

07 Sep

Siliciclastic Reservoirs of the Middle East Call for Posters Expires in 93 days

litutmMedium

View All Deadlines ...

Bulletin Article

Linking process, dimension, texture, and geochemistry in dolomite geobodies: A case study from Wadi Mistal (northern Oman)

Understanding the distribution and geometry of reservoir geobodies is crucial for net-to-gross estimates and to model subsurface flow. This article focuses on the process of dolomitization and resulting geometry of diagenetic geobodies in an outcrop of Jurassic host rocks from northern Oman. Field and petrographic data show that a first phase of stratabound dolomite is crosscut by a second phase of fault-related dolomite. The stratabound dolomite geobodies are laterally continuous for at least several hundreds of meters (1000 ft) and probably regionally and are one-half meter (1.6 ft) thick. Based on petrography and geochemistry, a process of seepage reflux of mesosaline or hypersaline fluids during the early stages of burial diagenesis is proposed for the formation of the stratabound dolomite. In contrast, the fault-related dolomite geobodies are trending along a fault that can be followed for at least 100 m (328 ft) and vary in width from a few tens of centimeters to as much as 10 m (1–33 ft). Petrography, geochemistry, and high homogenization temperature of fluid inclusions all point to the formation of the dolomite along a normal fault under deep burial conditions during the Middle to Late Cretaceous. The high 87Sr/86Sr ratio in the dolomite and the high salinity measured in fluid inclusions indicate that the dolomitizing fluids are deep basinal brines that interacted with crystalline basement. The dolomitization styles have an impact on the dimension, texture, and geochemistry of the different dolomite geobodies, and a modified classification scheme (compared to the one from Jung and Aigner, 2012) is proposed to incorporate diagenetic geobodies in future reservoir modeling.

Added on 30 June, 2013

Bulletin Article

A transition from carbonate shelf to pelagic basin environments of deposition: Rifting and depositional systems in the Jurassic of northeastern Tunisia

Jurassic deposition in the Maghrebian tethys was governed by eustasy and rifting. Two periods were delineated: (1) a carbonate shelf (Rhaetian–early Pliensbachian) and (2) a platform-basin complex (early Pliensbachian–Callovian). The carbonate shelf evolved in four stages, generating three sedimentary sequences, J1 to J3, separated by boundary sea level falls, drawdown, exposure, and local erosion. Sediment facies bear evidence of sea level rises and falls. Lateral changes in lithofacies indicate shoaling and deepening upward during the Sinemurian. A major pulse of rifting with an abrupt transition from carbonate shelf to pelagic basin environments of deposition marks the upper boundary of the lower Pliensbachian carbonate shelf deposits. This rifting episode with brittle fractures broke up the Rhaetian–early Pliensbachian carbonate shelf and has created a network of grabens, half grabens, horsts, and stacked ramps. Following this episode, a relative sea level rise led to pelagic sedimentation in the rift basins with local anoxic environments that also received debris shed from uplifted ramp crests. Another major episode spanning the whole early Pliensbachian–Bajocian is suggested by early brecciation, mass flows, slumps, olistolites, erosion, pinch-outs, and sedimentary prisms. A later increase in the rates of drifting marked a progress toward rift cessation during the Late Jurassic. These Jurassic carbonates with detrital deposits and black shales as the source rocks in northeastern Tunisia may define interesting petroleum plays (pinch-out flanking ramps, onlaps, and structurally upraised blocks sealed inside grabens). Source rock maturation and hydrocarbon migration began early in the Cretaceous and reached a maximum during the late Tortonian–Pliocene Atlassic orogeny.

Added on 30 June, 2013

Bulletin Geologic Note

A new theoretical approach to model sorption-induced coal shrinkage or swelling

The shrinkage or swelling of coal as a result of gas desorption or adsorption is a well-accepted phenomenon. Its impact on permeability changes has also been recognized for two decades. Its importance has increased significantly because of the potential of coals that are not likely to be mined and depleted or nearly depleted coalbed methane reservoirs to serve as CO2 repositories. This article proposes a new theoretical technique to model the volumetric changes in the coal matrix during gas desorption or adsorption using the elastic properties, sorption parameters, and physical properties of coal. The proposed model is based on the theory of changes in surface energy as a result of sorption. The results show that the proposed model is in excellent agreement with the laboratory volumetric strain data presented in the literature during the last 50 yr. Furthermore, the proposed model can be extended to describe mixed-gas sorption behavior, which can be applied to enhanced coalbed methane and CO2 sequestration operations.

Added on 30 June, 2013

Explorer Emphasis Article By Louise Durham

Diverse Dynamics Impact Bakken Productivity

Complex considerations: Mention the Bakken Formation and most people think of unlimited potential – but several dynamics have a huge impact on productivity.

Added on 01 June, 2013

Bulletin Article

Permian–Holocene tectonostratigraphic evolution of the Mandal High, Central Graben, North Sea

A three-dimensional seismic data set and published data from exploration wells were used to reconstruct the tectonostratigraphic evolution of the Mandal High area, southern North Sea, Norway. The Mandal High is an elongated southeast-northwest–trending horst. Three fault families in the Lower Permian sequence, inherited from the basement structural grain of Caledonian origin, are interpreted: (1) a north-northwest–south-southeast–striking fault family, (2) a northeast-southwest–striking fault family, and (3) a near east-west–striking fault family. In addition, an east-southeast–west-northwest–striking fault family (4) that formed during Late Jurassic rifting and was reverse reactivated in the Late Cretaceous is interpreted. We suggest that inversion occurred because of small dextral motion along fault family 1. A final fault family (5) displays various strike orientations and is associated with salt movements. Seven chronostratigraphic sequences defined by well data and recognized on three-dimensional seismic data are interpreted and mapped: Early Permian rifting in a continental environment; Late Permian deposition of the Zechstein salt and flooding; Triassic continental rifting; uplift and erosion in the Middle Jurassic with deposition of shallow-marine and deltaic sediments; rifting and transgression in a deep-marine environment during the Late Jurassic; a post-rift phase in a marine environment during the Early Cretaceous; and flooding and deposition of the Chalk Group in the Late Cretaceous. An eighth sequence was interpreted—Paleogene–Neogene—but has not been studied in detail. This sequence is dominated by progradation from the east and basin subsidence. Well and seismic data over the Mandal High reveal that large parts of the high were subaerially exposed from Late Permian to Late Jurassic or Early Cretaceous, providing a local source of sediments for adjacent basins. Similar to the Utsira High, where several large hydrocarbon discoveries have been recently seen, the Mandal High might consist of a set of petroleum plays, including fractured crystalline basement and shallow-marine systems along the flanks of the high, thereby opening up future exploration opportunities.

Added on 31 May, 2013

Bulletin GeoHorizon

Analog modeling of normal faulting above Middle East domes during regional extension

We study the effects of planform dome shape on fault patterns developing with and without concurrent regional extension oriented oblique to the long axis of the dome. The motivation was the need to understand fault and fracture patterns in two adjacent mature hydrocarbon fields in the Middle East: one, an elliptical dome, and one, an irregularly shaped dome. The largest faults have throws of approximately 30 m (98 ft), which is close to the resolution limit of older two-dimensional seismic reflection data. The known fault trends are not parallel to the highest transmissivity direction but could form compartment boundaries. Fault and fracture patterns developed over the modeled domes provide insight into the populations of faults and fractures that are likely to exist in the reservoirs but have been undetected because they are at or below the resolution limit of reflection seismic data. Major domal structural elements, crestal fault systems, end splay systems, and radial faults are observed in modeled domes rising both with and without concurrent regional extension. Experimental results indicate that fault and fracture patterns are influenced by the effects of dome shape, regional extension, and relative timing of uplift with respect to regional extension. The expression of particular sets of faults and fractures associated with concurrent doming and regional extension depends on the interaction among regional extension, outer arc extension over the dome, and tangential extension around the dome margins. Our results also indicate that the two adjacent natural domes possibly experienced different kinematic histories from those previously interpreted.

Added on 31 May, 2013

Explorer Geophysical Corner By Alistair Brown,Satinder Chopra

What Is Seismic Interpretation?

Seismic Interpretation is the extraction of subsurface geologic information from seismic data. On that definition we all are agreed.

Added on 01 May, 2013

Explorer Director’s Corner By David Curtiss

Taking Steps to Foster and Advance Science

Here at headquarters we are busy with final preparations for the trip to Pittsburgh for AAPG’sAnnual Convention and Exhibition (ACE) from May 19-22.

Added on 01 May, 2013

Explorer Emphasis Article By Louise Durham

Marcellus Turns Penn Prof Into a 'Celebrity'

Terry Engelder is a professor at Penn State and expert on the Devonian black shales – all of which has brought a bit of celebrity expertise to the campus and the Marcellus Shale.

Added on 01 May, 2013

Explorer Emphasis Article By Louise Durham

Levant Basin Brings Potential to New Areas

A new technical paper takes a look at the ongoing exploration success that can be found in the eastern Mediterranean's Levant Basin

Added on 01 May, 2013

Workshop

Kuala Lumpur, Malaysia

Monday, 2 October – Tuesday, 3 October 2023, 8:00 a.m.–5:00 p.m.

AAPG/EAGE New Discoveries in Mature Basins

AAPG and EAGE have teamed up to deliver the upcoming New Discoveries in Mature Basins workshop to be held from 2-3 October 2023 in Kuala Lumpur, Malaysia. Save the date! Registration to open soon.

Added on 28 November, 2022

Workshop

Khobar, Saudi Arabia

Monday, 9 October – Wednesday, 11 October 2023, 8:00 a.m.–5:00 p.m.

5th Edition: Siliciclastic Reservoirs of the Middle East

The fifth annual AAPG Siliciclastic Reservoirs of the Middle East Workshop will take place in Al Khobar in Saudi Arabia from 9 – 11 October 2023. This workshop will bring together professionals from the region to share their knowledge and experience related to siliciclastic reservoirs and showcase the best success stories in the industry on understanding and utilizing oil and gas siliciclastic reservoirs in the region.

Added on 16 November, 2022

Workshop

Khobar, Saudi Arabia

Monday, 4 March – Wednesday, 6 March 2024, 8:00 a.m.–5:00 p.m.

4th Edition: Stratigraphic Traps of the Middle East

Join us for the 4th Edition of: "Stratigraphic Traps of the Middle East" workshop. The workshop will be hosted by AAPG in Al Khobar, Saudi Arabia 4-6 March 2024.

Added on 16 November, 2022

Workshop

Paramaribo, Suriname

Wednesday, 17 January – Thursday, 18 January 2024, 8:00 a.m.–5:00 p.m.

Maturing Sustainable Solutions to, Explore, Develop and Produce Oil and Gas Across the Guyana Suriname Basin

Plan now to attend an interactive in-person workshop with industry leaders, government representatives and technical experts working in the Guyana-Suriname Basin.

Added on 02 November, 2022

Field Seminar

Lisbon, Portugal

Tuesday, 20 June 2023, 8:00 a.m.–5:00 p.m.

Late Jurassic Deep Water Depositional Systems from the Late Jurassic of the Lusitanian Basin

Come along on this 1-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, GeoBioTec - Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa. Gil Machado, ChronSurveys Lda & Instituto Dom Luiz Fees: €190 - Local VAT applicable Limit: 20 Participants Includes: Ground Transportation Snacks and Refreshments Lunch and Dinner Guidebook Departure Time/Location 20 June 2023 8:30am Hotel Dom Pedro 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 field trip 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.

Added on 06 February, 2020

Workshop

Lisbon, Portugal

Wednesday, 21 June – Thursday, 22 June 2023, 8:00 a.m.–5:00 p.m.

Mixed/Hybrid Systems (Turbidite, MTDs and Contourites) on Continental Margins

This 3-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.

Added on 06 February, 2020

VG Abstract By Juan I. Soto

How Orogens Could Collapse Forming Sedimentary Basins: The Case of the Betic-Rif Orogen

The Betic hinterland, in the westernmost Mediterranean, constitutes a unique example of a stack of metamorphic units. Using a three-dimensional model for the crustal structure of the Betics-Rif area this talk will address the role of crustal flow simultaneously to upper-crustal low-angle faulting in the origin and evolution of the topography.

Request a visit from Juan I. Soto!

Added on 26 June, 2019

VG Abstract By Juan I. Soto

Salt versus Shales in Continental Margins and Orogens

In comparison with the known boundary conditions that promote salt deformation and flow in sedimentary basins, the processes involved with the mobilization of clay-rich detrital sediments are far less well established. This talk will use seismic examples in different tectonic settings to document the variety of shale geometries that can be formed under brittle and ductile deformations.

Request a visit from Juan I. Soto!

Added on 26 June, 2019

Structure

Related Interests

See Also ...

STAY CONNECTED: