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Consultancy

I am engaged as carbonate consultant in projects for the oil industry providing custom-tailored training courses and seminars. These combine unique field and experimental datasets aimed at improve the know-how of the ‘Pre-salt’ non-skeletal carbonate-silica plays.
I have experience analysing and integrating outcrop, borehole (cuttings, cores, wireline logs), and thin-section information from marine and freshwater carbonate sequences (Middle Triassic of the Catalan Basin; Cretaceous of the Tremp Basin; Carboniferous of Scotland; Pleistocene and Holocene of USA, Australia, Italy).

I am currently running two field trips for geology students and geoscience specialists covering different aspects of microbial carbonate geology (sedimentology, petrology and gechemistry), and a classroom workshop on continental carbonates to refine our understanding of  the Pre-salt carbonate factories and its application to hydrocarbon reservoir exploration:

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WORKSHOP 1 # CONTINENTAL CARBONATES: APPLICATIONS FOR THE SOUTH ATLANTIC PRE-SALT DEPOSITS

Continental carbonates are extremely heterogeneous deposits that can accumulate in a large spectrum of depositional settings from freshwater, alkaline and saline lakes, freshwater palustrine, fluvial and calcrete environments, or sublacustrine to subaerial thermal springs.

During the first part of the workshop we will provide with the basic knowledge to understand continental carbonate environments, including facies, textures, geochemistry and the depositional processes controlling their occurrence and diversity.

In the second part, we will critically review the lessons learned from outcrop analogues, experimental datasets and numerical models to offer an integrated process-product perspective of the Pre-Salt non-marine reservoirs from offshore Brazil and West Africa.

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Left to right, up: Lake Clifton thrombolite bioherms in the littoral to sublittoral lake zone. Travertine fissure-ridge geomorphological elements (from Brogi et al., 2014). Left to right, bottom: Tufa forming deposits in fast flowing steeped waterfalls. Cyanobacterial autofluorescence (red rim) on top of a crystalline shrubby travertine layer (from Okumura et al., 2012). Mono Lake spring tufa chimneys outcropping in the lake shore at Lee Vining (California) (photo by Eric Wagner). Centre: Power-point material from the course.

In this workshop, we will:

– Review the physical, chemical and biological processes involved in continental carbonate precipitation and deposition in calcareous  springs, hot-springs, lacustrine, palustrine and pedogenic environments

– Review the controls on facies, mineralogy, crystal morphology and sedimentary architecture of continental carbonates based on updated literature (outcrop, thin- section, geochemical, SEM data)

– Analyse selected outcrop case studies, and experimental, geochemical, and numerical data to provide with a refined framework to understand the Pre-Salt carbonate occurrences of the South Atlantic margins

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Left to right, up: Cross-section deposit of coated bubbles accumulated in the depressions formed by fan/ray crystals (Tivoli, Italy). Hot-spring emergence forming mounded geometries and annular microterracettes (Il Bollore, Italy). Left to right, bottom: Lacustrine varves displaying alternation of lighter calcite-rich laminae and darker, organic-rich laminae. Pyramid Lake subaerially exposed spring mound outcropping in nearshore lake areas. Lithified microbial travertine made up of alternating radial crystal fans (from Okumura et al., 2012). Centre: Power-point material from the course.

FIELD-TRIP 1 # ARCHITECTURE AND BASIN EVOLUTION OF FAULT-BLOCK MICROBIAL-DOMINATED CARBONATE RAMPS (TRIASSIC, CATALAN BASIN, SPAIN): AN OUTCROP ANALOGUE FOR PRE-SALT OCCURRENCES

This field-trip is focused to gain insights on the facies architecture from marine carbonate systems dominated by microbial factories with examples from the Middle Triassic of the Catalan Basin (Spain). Special emphasis is given to the recognition of the facies heterogeneities and typical stacking patterns seen in carbonate ramp settings dominated by well-preserved, metre to seismic-scale stromatolitic to thombolitic deposits.

Fieldtrip Carbonate Consultancy Oil Industry Triassic Catalan Microbial Stromatolite Thrombolite Ramp Seismic Sequence Sedimentology Presalt Analogue Analog 1
Facies architecture of the microbial-dominated fault-block carbonate ramps of the Middle Triassic in the Catalan Basin (Spain). Seismic-scale biostromal and biohermal thrombolite successions are spatially related to the architecture of the half-grabens in middle ramp marine settings. Thrombolite deposits are covered by a terminal carbonate complex made up of coral patch-reef, dasycladal meadows and planar stromatolite successions. Following a sea-level drop of at least 50m, such carbonate units underwent pervasive karstification and were capped by extensive peritidal laminated deposits. All the images are copyrighted.

In this field-trip, attendees will learn more about the controls driving microbial carbonate occurrence across inner to outer ramp environments. They will have the opportunity to recognise outcrop to seismic-scale sedimentary geometries and stratal terminations, along with a wide array of depositional facies and sequence stratigraphic surfaces relevant to carbonate systems in rift tectonic settings.

Fieldtrip Carbonate Consultancy Oil Industry Triassic Catalan Microbial Stromatolite Thrombolite Ramp Seismic Sequence Sedimentology Presalt Analogue Analog 2
Thrombolite buildup facies maps displaying the sedimentary geometries at outcrop-scale. Karst-related features (collapse breccia and dissolution cavities) are recognised in association with the subaerial unconformity. Microfacies maps exhibiting the diversity of allochem and carbonate components characterising the clotted-thrombolite textures in thin-section. All the images are copyrighted.

FIELD-TRIP 2 # AN OUTCROP ANALOGUE FOR SPHERULITIC CARBONATES FORMED IN ALKALINE, VOLCANIC LAKES (CARBONIFEROUS, SCOTLAND): DEPOSITIONAL ARCHITECTURE AND ENVIRONMENTAL SIGNIFICANCE OF CARBONATE ALLOCHEMS

This second field-trip is focused on the recognition of the facies heterogeneities seen in shallow hyper-alkaline lacustrine and volcanic settings dominated by ‘non-skeletal’ carbonate factories. The field-trip takes place in the East Kirkton Limestone Quarry (Bathgate, Scotland) which is made up of a Carboniferous sedimentary succession of spherule-rich carbonate allochems formed in a volcanic and clay-poor alkaline lake setting.

This location represents an unrivalled outcrop analogue for the Cretaceous South Atlantic Presalt subsurface occurrences (Brazil and Angola), as allows to explore how these unusual carbonate settings looks like in outcrop. In this field-trip we will integrate outcrop, thin-section, geochemical and experimental data to better understand the origin and predict the occurrence of the analogous Presalt spherulitic carbonates within lacustrine successions.

Fieldtrip Carbonate Consultancy Oil Industry Carboniferous Sedimentology Lacustrine Kirkton Spherulite Presalt Volcanic Lake Alkaline Analogue Analog 3
The East Kirkton Quarry display metre-scale slumped laminite deposits that are interbedded by packstone to grainstone of millimetre-thick calcite spherules floating in a matrix of organic to muddy clay-free material. Spherules are stringly similar in terms of petrography, geochemistry and sedimentary environment to those documented in the South Atlantic Cretaceous Presalt lakes of Brazil and Angola. All the images are copyrighted.

In addition, we will review the current hydrogeochemical models put forward for the Presalt lakes critically evaluating the mechanisms considered by the different Schools of Thought to explain mineral paragenesis and carbonate textural variability. The effects of evaporation, CO2 magmatic input, mixing of waters, and leackage to underlying aquifers (or adjacent water bodies) will be evaluated in a basin-scale context. Thus, we aim at quantify the impacts that lake bathymetry, atmospheric CO2 pressure and water composition variations have in the mineral precipitation, facies distributions and cyclothem arrangement.

Kirkton Alkaline Lake Model Phreeqc Lacustrine Spherule Calcite Carbonate Sedimentology Training Course Bathymetry Talc Clay Mg
Up: 2D plots showing the volumes of calcite and talc precipitated across specific combinations of leakage and water mixing fractions per evaporative cycle in an alkaline lake case. Down: Depositional model of an alkaline volcanic clay-free lake producing calcite spherulite components like those encountered in the South Atlantic Presalt lakes. The factory of calcite spherules was located in the littoral zone where high carbonate saturation index conditions, and high Ca-Mg fluxes and organic acids are met. Reworking of allochems towards the sublittoral and profundal environments produce floatstone textures in muddy sediments. All the images are copyrighted.