N336 Carbonate Reservoir Description Based on Core and Well Data (Nottinghamshire, UK)

Course Facts

Course Code:
N336
Duration:
5 days
Type:
Classroom
CEU:
4.0 Continuing Education Units
PDH:
40 Professional Development Hours
Certificate:
Certificate Issued Upon Completion

Summary

Data obtained from core are critical components of exploration and development programmes, yet all too often the “soft” information obtainable from core is undervalued and underutilized. The integration of core and wireline logs with other data from carbonate reservoirs is key to: constructing reservoir-scale depositional models; referencing critical correlation horizons; understanding pore-scale issues; validating reservoir architectures; recognising and predicting heterogeneities and improving simulation models for reservoir performance and development planning.

Duration and Training Method

This five-day course will take the form of a practical workshop using cores, wireline logs, thin-sections, and core measurements supplemented by lectures, discussions and a half-day field excursion to the Castleton area to the northwest of Nottingham.  The course will be taught through the extensive use of core and associated datasets at the British Geological Survey facility in Keyworth, UK. Core examination and related practicals will be supported by lectures and a local field excursion that will provide a sense of scale and demonstrate the limitations inherent in a 1-dimensional core dataset.

Participants will learn to:

  1. Judge the value and application of core in exploration, appraisal or development settings.
  2. Plan the best approaches to logging core; assess and calibrate data and correct core-to-log shifts.
  3. Employ a range of techniques used to describe and integrate core and wireline log data; judge the limitations of such techniques and data.
  4. Characterise carbonate grain types, mineralogy, textures, fabrics and facies in core and thin-section; evaluate which depositional models and potential analogues to invoke from a core description.
  5. Gauge the reservoir impact of fundamental aspects of carbonate pore types and diagenesis.
  6. Recognise principal stratigraphic features, such as sequence boundaries, cycles and other key stratigraphic surfaces that may have dynamic reservoir impact.
  7. Assess carbonate pore types, including microporosity, and evaluate potential influences on fluid flow and recovery within a sequence stratigraphic framework.
  8. Identify and characterise problems that may arise during production of carbonate reservoirs due to stratigraphic heterogeneities such as high permeability zones.
  9. Integrate varied data sets to best characterise carbonate reservoir architecture and prediction.

This is a five-day core seminar based at the British Geological Survey core laboratory at Keyworth near Nottingham. Themed lectures will introduce suites of carbonate and evaporite cores and associated datasets from onshore and offshore UK wells, the Middle East and North Africa. There will be a half-day field excursion to an exhumed Early Carboniferous boundstone/grainstone carbonate platform margin and interior in the Castleton area to the north of Nottingham.

The integration of core and borehole logs with other data from carbonate reservoirs, in particular, is key to:

  • the interpretation of depositional environments and the construction of reservoir-scale depositional models;
  • referencing critical correlation horizons identified on wireline logs;
  • understanding petrophysical properties for log interpretation;
  • understanding any pore-scale issues within a reservoir;
  • validating reservoir architectures interpreted from logs and seismic data;
  • recognising and predicting carbonate reservoir heterogeneities such as potential high-k zones or permeability baffles as well as the scales of heterogeneity from pores to stratigraphy;
  • improving reservoir simulation models, upscaling of rock properties with the ultimate aim of improving reservoir performance and long term development planning.

These topics will be addressed and discussed through examination of a range of core and data suites of the principal carbonate reservoir types:

  1. Ramps
  2. Intra-shelf basins and source rocks
  3. Platform facies belts
  4. Reefs
  5. Basinal facies, source rocks and chalk
  6. Carbonates and evaporites

Probable cores and datasets include:

  1. Corallian (UK)
  2. Zechstein arid evaporate-carbonate system (North Sea)
  3. Cretaceous rudist-dominated platform (Tunisia)
  4. Maastrichtian Chalk (UK)
  5. Jurassic Arab D (Arabian Gulf)
  6. Great Oolite (UK)

Provisional Itinerary

Day 0

Participants arrive in Nottingham for the start of the course.
Icebreaker and introduction to the course.

(Note that the group will be travelling daily by coach or minibus from the hotel in Nottingham to the BGS facility in Keyworth, a distance of around 10 miles. All transport will be arranged.)

Day 1: Value of core in carbonate reservoir studies:

Core vs other data sources (e.g. wireline logs, seismic, etc.); Description techniques (core logging, sample selection, mineral identification, palaeontology, etc.)

  • Carbonate rock components and textures; petrography
  • Exercise and review
  • Carbonate depositional systems: modern and ancient
  • Exercise and review

Physical measurements on core (routine poroperm, SCAL, rock properties, whole core analysis, CAT-scan, ambient vs reservoir condition measurements, hardness, reconciling with other data, etc.)

  • Core exercise on Middle East Mesozoic
  • Review

 

Day 2: Carbonate sequences, cycles and surfaces:

Carbonate platform architecture in a sequence stratigraphic framework, including the critical issue of cyclicity and the impact of stratigraphic surfaces on reservoir quality: surfaces (sequence boundaries, exposure surfaces, karst); recognition and implications of repetitive successions, cycle scales, stacking patterns and reservoir architecture

  • Core and log exercise on Carboniferous ramp grainstones
  • Review
  • Core exercise on Upper Jurassic reef reservoir
  • Review
  • Core exercise on Cretaceous intraplatformal basin reservoir  cycles
  • Review

Day 3: Unconventional carbonates and source rocks:

Source rocks and pelagic/hemipelagic successions

  • Core and log exercises including North Sea chalk reservoir
  • Review

Field excursion to Castleton area, Derbyshire:

A Carboniferous platform and its exhumed petroleum system

  • Transect across a Carboniferous isolated platform analogous to Pre-Caspian super-giant fields, from rim to cyclic platform interior.
  • The group will depart BGS Keyworth at around 1200 and arrive in Castleton area at approximately 1400. There will be an evening meal in the Peak District National Park. Note that there will be a late return to the hotel in Nottingham (2230). Appropriate field clothing and footwear is required.

Day 4: Correlation in carbonate and carbonate-evaporite systems:

Correlation issues in salt basins; large scale stratal geometries and clinoforms.

  • Core and log exercise on Jurassic Arab Formation (Middle East)
  • Review

Basin-platform sequences in salt basins

  • Core and log exercise on Permian Zechstein of UK sector
  • Review

Jurassic oolitic reservoirs, onshore UK

  • Core and log exercise
  • Review

Day 5: Large multi-data exercise:
Core description and interpretation, integration of well log suite, core plug and petrographic data, extrapolation and correlation with additional well logs to plan the location of a step-out well. Cores and data sets from a producing field in North Africa. Review of interpretations. Course finishes by approximately 1600.

Who should attend

This course is designed principally for geoscientists, geomodellers and reservoir engineers engaged in the characterisation, appraisal and development of carbonate reservoirs. It will provide an understanding of the key carbonate reservoir heterogeneities as well as the limitations of subsurface data that will be valuable in building static and dynamic reservoir models.

Prerequisites and linking courses

The course is an advanced course and attendees are expected to have a basic knowledge of carbonate rocks and well log interpretation. Prior attendance on Foundation level course N020 (Carbonate Depositional Systems: Reservoir Sedimentology and Diagenesis) and N003 (Geological Interpretation of Well Logs) along with work-related projects will provide a suitable background.

This course is complimentary to our Skilled Level field courses including: N059 (Applied Carbonate Geology: Carbonate Facies and Reservoirs, Balearic Islands, Spain), N091 (Carbonate Reservoir Architecture and Applied Carbonate Sequence Stratigraphy, West Texas), N235 (Exploring for Carbonate Reservoirs, Dolomites), N143 (Advanced Concepts in Carbonate Exploration and Reservoir Characterisation, Northern Spain).

Full details of possible linking courses on the Nautilus portfolio can be found on the website at: training.rpsgroup.com

Click on a name to learn more about the instructor

Trevor Burchette

Paul Wright

Excellent course really bridging the gap between seismic/models and pore scale understanding, really valuable. I also appreciated the sessions on acquisition/handling of core.