Saltwork courses in applied carbonate sedimentology

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1 Summer 2018 Saltwork courses in applied carbonate sedimentology We are committed to offering up to date and comprehensive applied understandings across all our training modules

2 intro A TRAINING MESSAGE FROM THE SALTWORKS The catalog outlines the various training modules we offer across all applied aspects of carbonate reservoir studies. Our course structure is modular so you, or your training coordinator, can construct a training program that meets your particular needs. The recommended program length for carbonate studies is three days made up of two days of the understandings modules (3000 code # s), followed by a more specialized one-day program. This specialized third day is made up of two advanced modules covering topics of specific interest. Historically, some of the most popular advanced modules are; 1) Wireline in carbonates 2) Dolomitization 3) Reef plays in SE Asia This program can be supplemented with specific topics related to carbonates in saline systems as you can select from all modules in the evaporite catalog, e.g., 1) Evaporite basins 2) Salt tectonics 3) Saline reservoirs We can also integrate our training with problem-specific data your staff are working on, including; core, wireline, rock property, seismic and other data. Introductory aspects of training in the use of these data are also possible, for example, an introductory module dealing with basic wireline interpretation. Contact us to discuss a course for you. enquiries@saltworkconsultants. com

3 CARBONATE RESERVOIR FRAMEWORK Geologists and geophysicists working in carbonate reservoirs know that to understand and predict reservoir quality needs more than the application of a simple depositional model. Such simple models may suffice for sandstone reservoirs, but in carbonates, the original depositional poroperm is often radically altered by a combination of diagenetic and structural overprints. Some interesting facts: More than 60% of the world s oil and 40% of the world s gas reserves are stored in carbonate reservoirs. The Middle East is dominated by carbonate fields, with around 70% of oil and 90% of gas reserves contained within these reservoirs. Carbonates typically exhibit highly varying properties (e.g., porosity, permeability, flow mechanisms) within small sections of the reservoir, such variations are often the result of variable diagenetic fluids crossflows and structural alteration, making them difficult to characterize. Classic sequence stratigraphic and wireline interpretation paradigms need to account for this variability if reservoir volumetric calculations are to be accurate Saltwork s applied carbonate course modules are designed to understand better the reservoir s porosity distribution, fluid saturation, and the mechanisms by which pores are linked to allow flow. This leads to improved wireline and seismic interpretation and knowledge of how to apply this understanding in improved exploration and development efficiencies. Contact us:

4 understandings (2 days) To deal with more specialized reservoir quality topics, the trainee must first gain a rock-based understanding of a carbonate reservoir and its diagenetic evolution within a tectonic and climatic framework. The four modules listed on this page give participants the comprehensive background and conceptual frame needed to tackle the more advanced topic sets. Once these more general topic sets are mastered, the client company can choose which of the advanced topic sets best fit their training needs. The advance modules can be arranged to constitute a total of three days (2 advanced modules on the third day) up to five days (with six advanced modules).

5 What defines carbonate sediment? Great Barrier Reef, Australia Limestones and early dolomites are deposited with distinctive textures that can indicate the original depositional setting, ocean chemistry and water depth Carbonate grains Depositional textures Altered textures Mud in carbonates Classification of carbonates Why carbonates are complex Diagenetic evolution Carbonate texture and rock chemistry preserve evidence of as the various diagenetic fluids it was exposed to during burial, re-equilibration and uplift Marine cements Meteoric alteration The burial evironment Uplift and alternation Isotopes and other tracers Abyss Cave,Belize Porosity and permeabilty Carboniferous dolomite Unlike sandstones, porosity and permeability distributions in ancient carbonates are rarely directly related to the depositional setting. Rather they indicate a complex interplay of depositional and diagenetic factors Ø & k textural variation Choquette and Pray Ø types Lucia classes & k predicition Classes & reservoir quality Poroperm trends & burial Diagenetic geometries Carbonate geosystems in time GBR The modern gives a limited sampling of epeiric and saline basins. This reflects the limited climatic and tectonic spectrum of today. Past systems were more extensive and variable Eustasy, greenhouse, icehouse Epeiric seaways and giants Eustacy, karst, present & past Are carbonates different? Are all carbonates fractured?

6 Advanced topics These advanced topics are designed as modules that follow on from the understandings topics. There are a total of six advanced topic modules, and each is 0.5 day long. If all six modules are chosen, this will constitute a five-day training program. If only two are of interest then, in combination with the four modules of the understandings program, the total course length will be three days. All modules emphasize the utility of applied geological knowledge in improving efficiencies during carbonate exploration and field development.

7 Scott Reef Reef spur and groove Dolomitization Most dolomite is a diagenetic mineral phase. Sometimes dolomitization enhances reservoir quality, other times it destroys it There are many types and styles of dolomite, some are economically significant and can have recognisable criteria at both the local (wireline) and regional scales. Some sequences maintain economic levels of dolomite induced or enhanced poroperm, while overdolomitisation destroys it Models & geobodies Permeability contasts Reservoir linkages Wireline Interp. Wireline-based porosity logs give values that are typically not reliable representations of values in the reservoir. The module defines petrophysical effects of matrix and porosity variability and the effects on m, n and Sw in a variety of carbonate textures. Using Archies Law, it then applies this knowledge to quantify better the reservoir Conventional Ø logs Matrix vs response What is a real m & n? Reliable Ø interp Combining logs Sequence stratig. The high solubility of evaporitic salts, especially the potash bitterns means there are particular problems and hazards associated with the utilisation of bedded and halokinetic potash. Pervasive natural karst typify all past and present salt deposits. Effects of these natural geohazards can be increased if flood possibilities are not accounted for from the sinking of the first shaft and throughout the life of the mine Different to sst Sealevel & carbonate Diagenesis in seismic Cretaceous dolomite Diagenesis San Andres reservoir Bypass reef wall

8 Advanced topics...cont d Carbonate reservoirs have a level of matrix and structural complexity not seen in the sandstone reservoirs of the world. This makes understanding and prediction more difficult These advanced and more topic-specific modules explore the detail and predictive outcomes that occur with a better understanding of the hydrocarbon-carbonate association. The topic sets extend the trainee s understanding beyond the fundamentals garnered in the first two days of the carbonate training program.

9 Fractures Moorea Rhodalgal wackstone Reservoir & seal Reservoir sedimentation and diagenesis (poroperm evolution) varies from field to field and region to region across the Phanerozoic. Understanding the depositional, climatic and diagenetic controls on these variations is critical to effective and efficient petroleum exploration and field development. The module gives a predictive understanding of carbonate reservoirs distribution within a climatic and plate tectonic framework. Platform & basin scalings Diagenesis and geobodies Predictive reservoir models Sequence stratig. Carbonate sediments are mostly biogenic (a carbonate factory is photic) and, once deposited, are subject to the vagaries of diagenesis. These factors must be considered during sequence stratigraphic modelling and the definition of sequence boundaries This is especially apparent if seismic and eustatic interpretations and poroperm patterns have already been done, based on the siliciclastic assumption that regional sedimentation patterns are largely a response to physical energy and sealevel. Carbonate eustacy over time Highstand versus lowstand Early diagenetic intensity Reef plays in Asia Most reservoirs producing from carbonates in SE Asia are hosted in Oligo-Miocene sediments. Unlike the giant fields in the reef-rimmed carbonate platforms of the Middle East and the Americas, these SE Asian fields occur are typically smaller and hosted in bedded heterozoan sediments. This module classifies the various carbonate fields of SE Asia and discusses why they and their depositional models are distinctive, when compared with classic carbonate platform models. Climate & tectonism Island arcs & foreland basins Carbonates in tectonicallyactive settings Fluid and tectonic evolution creates traps and seals The Quaternary is not a perfect key to the past SE Asian reservoir plays are distinct Reservoirs by area Reservoirs by time Reservoir diagenesis Reservoir prognosis r Controls on sealevel Earth climate & time Greenhouse seaways Basin scale prognosis Defining the Miocene Light & island arcs Miocene reservoirs Prediction in SE Asia

10 Additional topics Many evaporite basins contain enhanced volumes of hydrocarbons in the sedimentary basin. This is especially apparent in the Middle East and the Circum-Atlantic salt basins. These are the regions where the majority of the world s giant and supergiant oil and gas fields have been discovered in the past 15 years. Saltwork training focuses on the evaporite association in a separate set of course modules (see our evaporite course catalog, which is downloadable from the Saltwork website). Three relevant modules from the evaporite training system are given here to give a feel for content in the evaporite-related training modules. These three, and all the other training modules listed in the evaporite training catalog, can be chosen as additional half-day modules in all client-designed training courses. enquiries@saltworkconsultants.com Website:

11 Salt kinetics Bitumens in Ara salt Hutt Lagoon Salt tectonics Many of the world s oil and gas fields occur in halokinetically-influenced structures across many of the world s salt basins (e.g. Campos Basin, Gulf of Mexico, North Sea, Lower Congo Basin, Santos Basin and Zagros). The course gives a predictive understanding of salt and how it controls local and regional salt tectonics, reservoir sedimentation and diagenesis (poroperm). This is critical to effective and efficient petroleum exploration and field development. Salt tectonics & basin-scales Predictive salt models Circum-salt diagenesis. Salt flows and so creates traps and fluid foci Saline reservoirs A large proportion of the world s giant and supergiant oil and gas fields are associated with salt. With carbonate reservoirs, this proportion is more than 50%. This is especially apparent in the Middle East and in circum-atlantic Aptian settings. Worldwide, all giant and supergiant gas fields in thrust belts have an evaporite seal. Salt acts a seal to underlying and adjacent reservoirs. In diagenesis it supplies brines than can create or enhance reservoir poroperm. Physics of salt seals Bedded associations Halokinetic associations Dolomite & evaporites. Salt maintains its seal integrity Source rocks Oil in carbonate reservoirs, sealed by evaporite salts, may have been sourced in earlier less saline, but still related, evaporitic (mesohaline) conditions. Similar conditions favour evaporite and organic matter preservation Halotolerants tend to flourish in mesohaline waters. Why feast and famine makes source rocks Organic geochemistry of halotolerants and halophiles Indicative biomarkers The four main ancient evaporitic source rock systems Time limits of the modern. Saline systems encourage the preservation of organics Physics of salt Extensional systems Compressional Circum-salt systems Salt seal integrity Beds, plays & plumes Halokinetic reservoir Dolomitisation & salt Salinity tolerances Halotolerant & philes Organic indicators Depositional settings

12 our promise At SaltWorks we are committed to offering up-to-date and comprehensive training. We also offer a full range of related consultancy services and a comprehensive GIS databases that encompasses all of the examples offered in any of our training modules. All data plots and polygons are cross-reference to their source data. Refer to our web page to see the complete range of services that we offer.

13 principal instructor Dr. John Warren is the principal expert and technical coordinator for Saltworks. His career spans more than 30 years in salty systems. Interests include; Wireline Analysis, Carbonate and Evaporite Systems, Oil and Gas, Economic Geology and Potash exploration and development. He has written 4 books on economic aspects of evaporites, has contributed related chapters in a number of books and has published more than 60 scientific articles in applied aspects of saline geology. course materials Each participant in the course receives a complete set of digital course notes. This material is a series of hi-resolution pdf files that give the participant a copy of every slide presented during their training course. In addition, each participant receives a digital copy of Dr. Warren s 2016 book Evaporites: A compendium published by Springer (ISBN ). This all-color edition runs to more than 1800 pages and has been cited as the most complete summary of evaporites currently available.

14 SaltWork Consultants 2015 (ACN ) Kingston Park, Adelaide 5049 AUSTRALIA Telephone: (Australia) (roaming/sms) Web page: jkwarren@saltworkconsultants.com