Reservoir Characterization Archives

Building a Reservoir Model, Pembrokeshire, UK (G055)

Tutor(s)

Mark Bentley: TRACS International Consultancy and Langdale Geoscience.

Overview

This course offers a software-independent view on the process of reservoir model design and simulation model-building, addresses the underlying reasons why some models disappoint and offers solutions that support the building of more efficient, fit-for-purpose models. The thread through the week is a model design for the notional ‘Pembroke Field’ – a synthetic field constructed from reservoir analogue outcrops in South Pembrokeshire.  The Pembroke Field contains three contrasting reservoir types: continental clastics, shallow marine deltaics and naturally fractured carbonates, in both structurally deformed and undeformed settings. Data from producing oil and gas fields has been scaled to the synthetic models to create a realistic hydrocarbon field accumulation, ready for development.

Objectives

You will learn to:

Create a fluid-sensitive conceptual model for a heterogeneous reservoir, built from a selection of elements and placed in a realistic architectural framework: the “sketch”.
Guide the use of geostatistical tools intuitively, balancing deterministic and probabilistic components with awareness of the limits of the tools.
Select appropriate methods for modeling of matrix properties, including the handling of net (cut-off’s vs total property modeling).
Evaluate options for multi-scale modelling and the possible need for multi-scale approaches based on hierarchical understanding of Representative Elementary Volumes (REV).
Understand issues surrounding permeability modeling and why this differs from the handling of other properties.
Learn a rule of thumb (“Flora’s rule”) to help assess what level of static model detail matters to flow modeling and forecasting.
Review how to use well test analysis to constrain models.
Review options for model-based uncertainty handling (base case led, multi-deterministic scenarios, multi-stochastic ensembles), learn how to post-process the results and how to select an appropriate workflow which minimizes impact of behavioral bias.

Exertion Level

This class requires an EASY exertion level. Field stops require short walks along coastal paths, beaches and wave cut platforms. The longest walk is <5km (3 miles). Field stops are all at approximately sea level and some are tide dependent. Transport will be by coach.This class requires an EASY exertion level. Field stops require short walks along coastal paths, beaches and wave cut platforms. The longest walk is <5km (3 miles). Field stops are all at approximately sea level and some are tide dependent. Transport will be by coach.

Level and Audience

Intermediate. The course is aimed at geoscientists with knowledge of reservoir modeling software, petrophysicists who provide input to static reservoir models and reservoir engineers involved in simulation work who deal with the static-dynamic interface on a regular basis. The course is also of benefit to team leaders who wish to have a deeper understanding of the principles behind modeling and how to QC models made by others.

Duration and Logistics

7 days; a mix of field work (70%), and classroom exercises (30%).

Characterization of Clastic Reservoirs: Workflows for Reservoir Evaluation (G035)

Tutor(s)

Rene Jonk: Director, ACT-Geo Consulting and Training; Honorary Professor, University of Aberdeen.

Overview

Reservoir mapping at production scale has to be performed with an understanding of clastic depositional systems, with full integration of core, core-plugs, well logs, seismic and production and engineering data. The variation in reservoir architecture of most common deposition-system morphotypes strongly influences development and production strategies, as well as in mapping techniques for not only the field scale but also to increase chances of finding near-field opportunities. The workshop examines common reservoir facies in transitional-marine to deep water systems, from fluvio-, wave- and tidal-dominated deltas, incised valleys, deep water channel systems and distributary channel lobe systems (deep water fans). Discussions include dimensional data of sand bodies in the different environments and recognition criteria in cores, well logs and seismic. The class will present optimized workflows for reservoir mapping, including the definition of the deliverables that need to be achieved in different business stages, focusing on when, why and how to develop them.

Duration and Logistics

Classroom version: 3 days; a mix of lectures (55%), core observation (10%) and hands-on exercises (35%). The manual will be provided in digital format and participants will be required to bring a laptop or tablet computer to follow the lectures and exercises.

Virtual version: Five 4-hour interactive online sessions presented over 5 days. A printed manual and exercise materials will be distributed to participants before the course and several exercises are to be completed by participants off-line.

Level and Audience

Advanced. This course is intended for geologists, geophysicists and petrophysicists with basic training in sequence stratigraphy and basic clastic facies.

Objectives

You will learn to:

Recognize different environments of deposition (EoDs) in cores, emphasizing typical facies stacking in common transitional marine and deep marine reservoirs.
Classify facies and stacking in typical transitional marine to deep marine EoDs.
Mechanisms for sediment transport in different EoDs and impact on reservoir rock properties.
Integrate core and core plug information in reservoir analysis, tying to well log and seismic data.
Recognize typical log patterns in different depositional systems.
Recognize typical seismic map views and cross-sectional views of sand-rich EoDs.
Apply mapping techniques for well logs and seismic with emphasis on identification of EoDs.
Make pre-drill predictions based on understanding of EoDs and seismic response.
Understand dimensional data for sandbodies in different EoDs
Implement reservoir mapping workflows that emphasize data integration and focus on deliverables in different business stages.

How to Make a Good Reservoir Model: It’s Not the Software, It’s the Design (G036)

Tutor(s)

Mark Bentley: TRACS International Consultancy and Langdale Geoscience.

Overview

How can you tell the difference between a ‘good’ reservoir model and a ‘bad’ one? This short, focused class is designed to draw out the common reasons for ‘good’ and ‘bad’ outcomes, under the premise that models add value only when they add clear value to business decisions. The theme throughout the event will be the overriding issue of model design and the five areas of common error: model purpose; selection of elements; use of determinism and probability; model scale; and uncertainty handling. Advice will be given on how to review models, what questions to ask the model builders, and how to determine whether the output from models can be relied upon and used to support decisions. The course will close with a set of questions to ask yourself and others, suitable for reference in peer reviews or assists.

Duration and Logistics

Classroom version: A 1-day course comprising a mix of lectures, case studies and exercises. The manual will be provided in digital format and participants will be required to bring a laptop or tablet computer to follow the lectures and exercises.

Virtual version: Two 4-hour interactive online sessions presented over 2 days. A digital manual and exercise materials will be distributed to participants before the course. Some reading and several exercises are to be completed by participants off-line.

Level and Audience

Fundamental. Designed for people who want an update or refresh on working with reservoir models without having to spend a week out of the office. The class will provide an opportunity for learning, inspiration and discussion with other modelers.

Objectives

You will learn to:

Explain the common causative factors for modelling ‘disappointments’.
Define model purpose and explain the use of framing.
Understand the fluid sensitivity to selection of model elements.
Describe techniques for handling small-scale detail in large models.
Be able to select between techniques for quantifying uncertainty.
Implement QC tips to evaluate your (and other people’s) models.

Characterization, Modeling, Simulation and Development Planning in Deepwater Clastic Reservoirs, Tabernas, Spain (G076)

Tutor(s)

Mark Bentley: TRACS International Consultancy and Langdale Geoscience.

Overview

This course is led by a production geologist and reservoir engineer involved in deepwater reservoir development, and is presented as a practical reservoir discussion rather than purely a traditional geological field trip. The objective of this field course is to explore the reservoir modelling and petroleum engineering aspects of deepwater clastic reservoirs. The discussions highlight the linkage from depositional processes to geological architecture and flow heterogeneity in development planning. The Tabernas outcrops are very well exposed and offer examples of sand-rich and debris-flow-dominated reservoirs, high net:gross fan systems and classic mud-dominated facies. In particular, they give excellent insights into the reservoir heterogeneities occurring within apparently continuous ‘sand lobes’ and major channels.

Duration and Logistics

A 7-day field course based in Almeria, Spain, comprising a mix of field activities and exercises. Transport will be by SUV on paved roads and unpaved tracks.

Level and Audience

Advanced. The course is largely aimed at geologists and reservoir engineers working on deepwater developments. The course is best suited to multidisciplinary team of geologists, geophysicists, petrophysicists and reservoir engineers.

Exertion Level

This class requires a MODERATE exertion level. There will be multiple walks of up to 1km (0.5 mile) most days. The longest walk of the class is approximately 2km (1 mile), with an ascent (and descent) of 75m (245 ft). The field area is in Europe’s only desert region and participants should expect high temperatures and an arid working environment. Participants should also be prepared for sudden and heavy rain showers.

Objectives

You will learn to:

Assess the genetic processes that produce slumps, slides, debrites and high/low density turbidites, and explain why the concept of confinement underpins the description of heterogeneity in deepwater clastic systems.
Evaluate the extent to which pay is under-/over-estimated in mud-rich/sand-rich systems, respectively, and the resulting errors in STOIIP and PI estimation.
Organise a detailed sedimentological description into key reservoir elements and build an architectural model using those elements.
Assess the basic principle of flow in porous media (Darcy) and describe how flow heterogeneity varies in layered and amalgamated clastic systems.
Appraise the contrasting heterogeneities in sand- and mud-rich systems and determine how much detail is required in a reservoir description based on a consideration of fluid type and production mechanism.
Evaluate how kv/kh impacts recovery in typical deepwater clastic architectures; optimally locate a well to optimize sweep for a range of architectural cases.
Judge length scale variations for a typical deepwater clastic system, and discuss how this would be handled in a reservoir modelling and simulation context.

Modeling and Development Planning in Carbonate Reservoirs, Provence, France (G034)

Tutor(s)

Mark Bentley: TRACS International Consultancy and Langdale Geoscience.

Overview

Using analogue outcrops in the Luberon and Cassis area of southern France, this course develops workflows for static and dynamic modeling in carbonate reservoirs, covering in particular the issues of conceptual reservoir characterization, the handling of scale and the representation of fracture detail in cellular models. The analogue section chosen is a direct analogue for Shuaiba/Kharaib Middle East reservoirs, including high and low energy areas of rudist platforms, inner and outer shelves, and chalks. The modeling principles are transferable to other carbonate environments.

Duration and Logistics

7 days; field activities and exercises (100%); the outdoors will be used as a classroom.

Level and Audience

Advanced. A course for technical professionals working in integrated teams who are planning development activities in carbonate reservoirs (reservoir engineers, geoscientists, petrophysicists) and all involved in reservoir and simulation modeling.

Exertion Level

This class requires an EASY exertion level. Provence is quite comfortable in the late summer to fall, with temperatures of 10-25°C (50-80°F) and occasional rain showers. The field locations are all easily accessible requiring only a short walk from the transport. The longest walk is approximately 0.5km (0.3 mile) along a road section. There will be one boat trip (weather dependent) to view key cliff exposures that can only be seen from offshore (1-2 hours duration).

Objectives

You will learn to:

Describe a carbonate reservoir in terms of essential reservoir elements and the architectural arrangement of those elements.
Evaluate reservoir property distributions for those elements in a form suitable for input to static/dynamic reservoir modeling.
Judge the scale at which a static/dynamic modeling exercise should be conducted, including any need for multi-scale modeling.
Prepare rules of thumb for effective property modeling in carbonates at a range of scales.
Assess fracture systems in carbonates and explain the options for modeling them (explicit DFN vs implicit effective properties).
Apply the concept of representative elementary volumes (REV) to fractured and unfractured carbonates.
Discuss optimal development planning for an oil reservoir based on the outcrops seen during the course.
Catch up with current research activities in carbonate reservoirs.

Reservoir Characterization of Deepwater Systems: Ross Formation, County Clare, Ireland (G023)

Tutor(s)

Rene Jonk: Director, ACT-Geo Consulting and Training; Honorary Professor, University of Aberdeen.

Overview

Given the high cost of exploration and development of deepwater reservoirs, it is essential to have an accurate pre-drill prediction of reservoir architecture and properties, and to integrate post-drill assessments of reservoir heterogeneity away from well penetrations. The outcrops of the Ross Formation offer a unique opportunity to observe seismic-scale exposures of a deepwater fan system with characteristics similar to the producing fields in West Africa, Brazil and the Gulf of Mexico, to name a few. The size and quality of the exposures allow the participants to observe the main building blocks of fan systems. Lobes and distributary channels can be observed from proximal to distal settings, with excellent exposures of vertical stacking and 2-D arrangements of these elements.

Duration and Logistics

A 7-day field course comprising a mix of field activities with exercises (60%) and classroom lectures with exercises (40%). Exercises emphasize practical applications and will focus on description of deepwater lithofacies, stratal geometries and recognizing key stratigraphic surfaces. The course is based in Kilkee Bay, Ireland, with participants flying in and out of Shannon, Ireland.

Level and Audience

Advanced. This course is intended for geoscientists, petrophysicists, engineers and managers who are seeking to gain a comprehensive understanding of deepwater reservoirs.

Exertion Level

This class requires an EASY exertion level. Access to the coastal outcrops is relatively easy and there will be walks of up to 2km (1.2 miles) most days, all at sea level. The longest walk on the class is approximately 3.2km (2 miles), with no ascent or descent over 50m (160 feet). Summer weather can be cool and wet, or warm and wet, with a daily temperature range of 4–24°C (40–74°F). Transport will be by van on paved roads.

Objectives

You will learn to:

Interpret and map different archetypes of deepwater reservoirs using cores, well-logs and seismic lines, from exploration to production business scales.
Define trap configurations and perform risk assessment for stratigraphic traps.
Estimate reservoir presence risk and predict N:G.
Interpret environments of deposition (EoDs) and related reservoir architecture, lithofacies associations and diversity.
Evaluate reservoir geometry and connectivity in different EoDs, integrating with production data.
Define depositional geometries of turbidites in seismic-scale outcrops.

Reservoir Characterization of Deepwater Systems, San Diego, California (G046)

Tutor(s)

Rene Jonk: Director, ACT-Geo Consulting and Training; Honorary Professor, University of Aberdeen.

Overview

Submarine canyons and deepwater channels are the primary conduits for the transfer of coarse sediments from the shelf to deep-water fans and they are today major targets for petroleum exploration. Southern California has had a long and complex geologic history that has involved many episodes of deepwater sedimentation in a variety of settings ranging from the Paleozoic passive margin of the North American craton to Mesozoic forearc and arc settings to Cenozoic transform, pull-apart, and continental borderland basins. These settings feature deep-water deposits in which both large and small submarine channels and fans played major roles as sediment transport routes and sites of sedimentation.

Duration and Logistics

6 days; a mix of outcrop examination and discussion (70%) and supporting classroom lectures (30%).  The field course is conducted in southern California along the coastline north of San Diego.

Level and Audience

Advanced. Geologists, geophysicists, and petroleum engineers working on deep water reservoirs from exploration to production.

Exertion Level

This class requires a MODERATE exertion level. Access to the coastal cliff outcrops is via sandy beaches, with most walks under 2 km. Some shallow wading on a sandy beach is also necessary in order to visit some outcrops.

Objectives

You will learn to:

Review deepwater lithofacies nomenclature and definitions, common lithofacies associations, and interpret lithofacies in outcrops and cores.
Interpret environments of deposition (EoD’s) and related reservoir architecture, lithofacies associations, and diversity.
Interpret sequence stratigraphic surfaces in outcrop, logs, and seismic in DW settings and related to vertical stacking of facies.
Use core and well-logs to interpret EoD’s.
Evaluate reservoir geometry and connectivity in different EoD’s.
Recognise the Do’s and Don’ts of using outcrops as reservoir analogs
Apply outcrop information as analog for reservoir model building
Evaluate seismic response, including geometry, facies, and acoustic response in deepwater EoD’s
Apply the criteria for the identification of Composite Sequences, Sequence Sets, and Depositional Sequences and their components in outcrops, cores, well logs, and seismic
Use interpretation and mapping techniques for cores, well-logs, and seismic lines in deepwater settings, from Exploration to Production business scales
Apply criteria and mapping strategies for play elements in deepwater depositional settings
Identify and map play fairways in deepwater settings.

Reservoir Geology for Engineers, Colorado and Utah (G061)

Tutor(s)

Mike Boyles: Retired Shell Oil; Affiliate Faculty, Colorado School of Mines.

Overview

The course investigates world-class outcrops to introduce engineers to a wide spectrum of stratigraphic and structural features commonly found in exploration and production. An active learning technique encourages participants to make initial observations and interpretations before group discussions. Lectures and exercises provide awareness of reservoir architecture while outcrops demonstrate field- and reservoir-scale heterogeneities. Depositional environments studied include deltaic, eolian, fluvial, turbidites, tidal and coastal plain with emphasis placed on understanding flow characteristics (i.e. connectivity, Kv, Kv/Kh).

Duration and Logistics

7 days; a mix of classroom lectures (10%) and field exercises (90%). The course begins and ends in Grand Junction, Colorado, and visits outcrops in Utah and Colorado.

Level and Audience

Fundamental. The material is presented with minimal jargon so that engineers get the full benefit of the course.

Exertion Level

This class requires a MODERATE exertion level. Scrambling over rock outcrops and steep sections will be required, but most hikes would be considered moderate. The longest walk is approximately 4.8km (3.2 miles). Outcrops are at elevations of 1200–2500m (4000–8200 ft). Weather conditions in NW Colorado and eastern Utah can vary from warm and dry to cold and wet, with an early fall temperature range of 5–23°C (41–73°F). Transport will be in SUVs on black-top and unpaved roads.

Objectives

You will learn to:

Appreciate the differences between a range of depositional settings, their facies and related reservoir architecture.
Use geologic knowledge to reduce reservoirs into flow units.
Gain a better understanding of major events that influence deposition and help to understand reservoir geometries and scale.
Evaluate the impact of modeling stochastic properties versus organized trends.
Understand the dangers of upscaling and if it makes geologic sense.
Use detailed sector models to understand how to capture subtle variations in the geology.
Appreciate how to use the geology to make upscaling decisions by building detailed sector models to understand the impact of upscaling decisions.

Reservoir Model Design (G025)

Tutor(s)

Mark Bentley: TRACS International Consultancy and Langdale Geoscience.

Overview

Considerable time is dedicated to reservoir model and simulation exercises in many companies but the results often disappoint: the time taken to build models is often too long, the models too detailed and cumbersome and the final model is ultimately not fit-for-purpose. This course examines the reasons why and offers remedies to fix these problems.

Duration and Logistics

Classroom version: 4 days; a mix of classroom lectures (60%), case studies (20%) and exercises (20%). The manual will be provided in digital format and participants will be required to bring a laptop or tablet computer to follow the lectures and exercises.

Virtual version: Four 4-hour interactive online sessions presented over 4 days, including a mix of lectures (60%), case studies (20%) and exercises (20%). A digital manual and hard-copy exercise materials will be distributed to participants before the course.

Level and Audience

Advanced. The course is aimed at geoscientists with knowledge of reservoir modeling software, petrophysicists who provide input to static reservoir models and reservoir engineers involved in simulation work who deal with the static-dynamic interface on a regular basis. The course is also of benefit to team leaders who wish to have a deeper understanding of the principles behind modelling and how to QC models made by others. The ideal group is an asset team who can join the course together.

Objectives

You will learn to:

Create a fluid-sensitive conceptual model for a heterogeneous reservoir, built from a selection of elements and placed in a realistic architectural framework: the “sketch”.
Guide the use of geostatistical tools intuitively, balancing deterministic and probabilistic components with awareness of the limits of the tools.
Select appropriate methods for modeling of matrix properties, including the handling of net (cut-off’s vs total property modeling).
Evaluate fracture properties, covering both faults and fault seal, and also flow through open fracture systems – understand how to model these practically.
Understand issues surrounding permeability modeling and why this differs from the handling of other properties.
Learn a rule of thumb (“Flora’s rule”) to help assess what level of static model detail matters to flow modeling and forecasting.
Review how to use well test analysis to constrain models.
Review options for model-based uncertainty handling (base case led, multi-deterministic scenarios, multi-stochastic ensembles), learn how to post-process the results and how to select an appropriate workflow which minimizes impact of behavioral bias.