Webinar Q&A – Michael Simmons Answers Your Questions

For subscribers to the Neftex product suite, these revisions are already in place. For example extra sequences in the Silurian. Hopefully some of these will be published in due course. I know that Mike Stephenson is taking a new look at the Permian.

Very important. It provides the basis for correlation, age calibration and palaeoenvironmental interpretation. Thus MFS and SB recognition. However, much work is still needed to establish the biostratigraphic value of many fossils (e.g. larger benthic foraminifera).

MFS can be in clean carbonates with low gamma values. Consider a depositional profile where the carbonates are outboard of the clay-rich lagoon. See papers by Maurer et al. and Droste in GeoArabia Special Publication 4 and Davies et al. 2002 in GeoArabia. But, yes always check the reason for log response carefully.

Those with time gaps, abrupt facies changes, but can occur in sand on sand relationships. Need to look multiple, not single sections.

In our proprietary work we use the depositional environment maps generated for each MFS and MRS and use these in a depth model to study reservoir effectiveness, source rock maturity, etc.

The sequence strat provides the time framework to integrate data on depositional environment. This can be integrated with tectonic information to generate paleo-digital elevation models and iteratively inform the palaeogeographies.

Great question. If eustasy was the only control the answer would be yes. But every succession has its local factors. Having said that, many sequences on the Arabian Plate are at least partly eustatic in origin. See a chapter in the new 2020 geological timescale book for a discussion of this.

Depends on context. Erosional surfaces can be generated by both autocyclic and allocyclic processes.

Yes, very much so. There are abundant papers on the Late Palaeozoic that demonstrate this. Isostatic effects can cause some diachroneity however, so care should be taken.

The most useful are typically abundances and diversity of planktonic organisms, but in purely platform carbonates other benthic fossils will have value.

There is a lot of cyclicity in the Lower Cretaceous of the UAE expressed as marl – carbonate cycles – where the marls are the expression of the land derived clays that are more pure in more proximal settings. See Davies et al. (2002) or Yose et al. (2006) (AAPG Memoir).

Actually both the Nahr Umr and Natih are rich in Orbitolina and neither indicate particular deep water. Remember that water depth is not the only factor controlling MFS position – consider a depositional transect and which facies are proximal and which are distal. See papers by Maurer et al. and Droste in GeoArabia Special Publication 4 and Davies et al. 2002 in GeoArabia.

The Arabian Plate model is applicable to Kurdistan. For examples, see the paper on the Triassic by Davies and Simmons (2018) in an EAGE Special Publication.

For sure! We are now in a time of transgression – the geological record of the past can help us understand the future state of the Earth.

These are essential. Only outcrops can really help us really capture all the stratigraphic details. I refer you to the excellent publications of Al-Mojel on the Jurassic of Saudi Arabia.

Two factors – have they really been looked for? And is seal effectiveness an issue? We need to develop concepts (e.g. lowstands) and then gather the relevant data to prove them up.

Not easily.

Some nice work has recently been published by Stephenson and Korngreen on the Permian of the Dead Sea region.

There is a lot of information on the initial Aptian sea-level rise and a glacio-eustatic late Aptian sea-level fall. See GeoArabia Special Publication 4.

Yes. If we develop stratigraphic trap concepts, such as lowstand plays, and then deliberately gather data to test these, they will be found. Large new discoveries continue to be made – the Middle East still has much to give.

Yes, from proximal vs distal facies, and parasequence stacking patterns. But it may not be easy…

About this webinar

The publication of Arabian Plate Sequence Stratigraphy in 2001 began a new phase of synthesis of Middle East geology. The application of sequence stratigraphy and the recognition of maximum flooding surfaces (MFS), placed all Arabian Plate geology within a meaningful framework from which could be extracted new play concepts, better selection of analogues, and regional depiction of geological risks in exploration.

Published descriptions of Middle East geology have grown significantly during the last 20 years. These, coupled with refinements in the application of sequence stratigraphy methodologies and regional geodynamics, allow the original sequence stratigraphic model to be updated. Within an ongoing review of the Mesozoic, certain sequence stratigraphic surfaces can be recalibrated in terms of age because of better biostratigraphic constraint or new insight into the sedimentary response to sea-level change, but many changes are relatively minor. When required, new reference sections can be proposed for each plate-wide MFS identified. Complementary sequence boundaries can be defined for the first time and associated with reference sections. Additional sequences can be proposed where data suggest that an additional plate-wide cycle of deposition is present, subject to biostratigraphic calibration. Comparisons suggest that many Arabian Plate sequences have a global significance.

Mike Simmons

Michael Simmons
Halliburton

Presenter Bio

Mike’s research interests encompass petroleum exploration workflows, especially integration with sequence stratigraphy; eustasy in the geological record; regional stratigraphy and petroleum geology, specifically the Middle East and Black Sea regions; applied biostratigraphy; and the history and future of geology. His career has spanned both industry and academia, working at BP, Aberdeen and Cambridge Universities, Neftex, and most recently Halliburton, where he is a Technology Fellow for Geosciences and Exploration. He has a degree and PhD from the University of Plymouth and is a Visiting Professor at the University of London.

Date & Time

Thursday, 21 May 2020 | 11:00 hours BST

COST

Free of charge.

PRESENTER

Michael Simmons

Technology Fellow for Geosciences and Exploration
Halliburton