Sedimentology and Depositional Environments of Deep-water Deposits

Trainer(s): Evert van de Graaff
Duration: 5 days

Business context

A good understanding of how depositional processes control the distribution of deep water reservoir and non-reservoir rocks in the subsurface is of fundamental importance to sound EP decision making. This applies throughout a field's life-cycle, all the way from the exploration phase, through appraisal, field development and finally field abandonment.

Who should attend

Geoscientists who need to fully understand the origins of deep-water sedimentary systems.

Course content

This is a 5 day course covering the theory and application of sedimentology and depositional environments of deep-water deposits. The course comprises an extensive series of topic-related modules, with provision to include workshops on Client &/or student datasets. The course can be concluded with a multiple choice test.

Learning, methods and tools

The lecture modules are supported and complemented by a number of paper-based exercises that are mostly built around correlation problems.

In addition to a full set of print-outs of the lecture materials & exercises, the book "Petroleum systems of deep water settings" by P. Weimer & R.M. Slatt, 2004 , SEG / EAGE is handed to the students [NB subject to availability from the publishers & to timely advice by the Client on the required number of copies].

Day by day programme

Day 1

Course Intro & Refresher: Why soft rock geology matters to the Oil industry

  • Topics: significance of stratigraphy & sedimentology to the E&P sector; impact of reservoir heterogeneity on fluid flow; sedimentary characteristics as a control on poroperm; fundamentals of reservoir modeling workflow; overview of sedimentary systems; correlation of well data and building the fluid flow model

Deepwater petroleum systems overview

  • Topics: deep water discoveries; fields in deep water vs fields in deep water deposits; petroleum systems in deep-water settings; trap styles in deep water; importance of mobile substrates [salt &/or shale]; exploration risk: importance of DHIs / AVO; offshore economics & need for high productivity; deep water development options.

Deepwater petroleum systems & source rocks

  • Topics: lacustrine source rocks in syn-rift settings; marine source rocks & sea level change; Black Sea: present day source rock factory; 'Ice House' vs 'Green House' oceanic circulation; Jurassic Kimmeridge Clay: submarine fan sands interfingering with source rock

Day 2

Deepwater mass-flow depositional mechanisms 

  • Topics: introductory overview and review of gravity-flow / mass-flow sediment transport mechanisms [slumps / debris flows / grain flows / turbidites]; three main settings: west coast California / sea level low-stands with deltas reaching shelf slope / seismically induced shelf slope collapse & Grand Banks case study; tectono-sedimentary setting as a control on mass-flow sediment transportation; review of slumps / debris flows / grain flows / turbidites and likely reservoir characteristics; turbidites - vertical [Bouma sequence] and lateral depositional characteristics; dimensions of turbidite systems; mud-rich / mixed sand-mud / sand-rich as a control of type of submarine fan; overview comparison clastic versus carbonate deepwater deposits

Deepwater contourite depositional systems

  • Topics: oceanic circulation systems; Hjulström / Sundborg diagram; examples of contourite deposits

Deepwater mass-flow clastic sedimentary systems

  • Topics: dimensions of clastic deepwater mass-flow systems; sediment supply to deepwater; linkage with sea level; glaciations & sea level; sea level low-stand > key control on turbidite sedimentation; submarine fan models & terminology, comparison deepwater fans - subaerial fans - deltas; autoclycicity; vertical sequence in fan deposits; thin bed effects [shaley sands evaluation] in basin plain & levee deposits; shelf edge collapse & megaturbidites; analogues from 3D seismic & from outcrops; proximal channel deposits > levee deposits > basin-plain deposits; 'milking' 3-D seismic to characterise deep water deposits; describing geometry of deep water deposits [translating geological jargon into descriptive terms]

Day 3

Refresher on carbonates: reefal build-ups as sources of deep water carbonates

  • Topics: comparison clastic & carbonate depositional systems; Bahama platform; sea level as key control on carbonate sedimentation; main types of carbonate factory - Tropical factory / Cool water factory / Mud mound factory; T-factory & M-mound factory: common sources of deep water carbonates; T & M factory during Phanerozoic; T-factory reefal systems - geometry & distribution

Slope & basin floor fan systems - Gulf of Mexico clastics case studies

  • Topics: Gulf of Mexico depositional system; salt diapirism as a control on sea floor topography; sea floor topography and turbidite sedimentation & distribution; turbidite classification & depositional architecture; value of inversion modeling for reservoir characterization

Slope systems Angola - clastics case study

  • Topics: stratigraphic & sedimentological setting; seismic expression; reservoir heterogeneity; core / log characteristics; reservoir characteristics

Proximal slope & basin floor settings North Sea - clastics case studies

  • Topics: Brae field - coarse grained proximal fan; reservoir heterogeneity & recovery; Schiehallion field - channelized turbidites; reservoir connectivity; Nelson field - channelized basin floor fan; delayed development of a 400+ million barrel UR field due to not understanding a 'dry hole'; impact of sea floor topography on sand distribution; crestal versus flank well control; impact on volumetrics of T/Z variation between crest and flank; impact of shaley sands on volumetrics

Day 4

Slope & basin floor fan systems - Nigeria - clastics case studies

  • Topics: Niger delta - depositional and structural characteristics; growth faulting & shale diapirs; slope mini-basins versus outboard plays; the outboard play - Bonga; reservoir heterogeneity, 4D seismic & fluid displacement; mini-basin play; depositional architecture & shale diapirism; stratigraphic reservoir compartmentalization; 3D seismic & reservoir characterization - value of AVO & inversion; shaley sands evaluation and production performance; reservoir compartmentalization & drive mechanisms

Carbonate mass flow deposits - case studies

  • Topics: Devonian reefs [Canning Basin - NW Australia]; fore reef setting - debris flows & olistostrome deposits; mixed clastic & carbonate system; Jurassic carbonate platform - slope - basin [Marocco]; proximal slope channel deposits versus distal basin plain deposits; Cretaceous fore reef deposits [Poza Rica / Golden Lane system - Mexico]; seismic expression; reservoir characteristics; seismic facies & prediction of reservoir characteristics; Cretaceous Chalks [North Sea]; pelagic deep water carbonates; Cretaceous 1st order high sea-level stand & carbonate sedimentation; allochthonous versus autochthonous chalks & reservoir quality; impact of Chixculub K/T event on reservoir quality; modern Bahama platform - distribution of deep water mass flow deposits; comparison clastic & carbonate deep water deposits; key characteristics & dimensions of carbonate slope deposits

Day 5     

Optional modules upon request [depending on students' general level of sedimentological / stratigraphic knowledge]

  • Module: Sea level & Eustacy fundamentals
  • Module: Sequence stratigraphy concepts

Overview and summary

Optional workshop module

  • Presentation by students of own data sets with review & discussion in workshop format

Multiple choice course test (optional on client request)