Clastic Reservoirs Field Seminar: Stratigraphic and Structural Heterogeneities That Impact Reservoir Performance
Study world-class outcrops displaying sandbody architecture in a variety of stratigraphic and structural settings to improve understanding of reservoir geometry and fluid flow characteristics.
Description
The course investigates world-class outcrops to introduce all subsurface disciplines 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 an awareness of reservoir architecture in a variety of stratigraphic and structural settings while outcrops demonstrate field- and reservoir-scale structural heterogeneities. Depositional environments studied include deltaic, eolian, fluvial, turbidites, tidal, lacustrine and coastal plain. Emphasis is placed on understanding flow characteristics (i.e. connectivity, Kv, Kv/Kh). A practical approach to using sequence stratigraphic concepts is also presented.
Duration and Logistics
A 5-day field course comprising 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. This course is presented with minimal jargon so that non-geoscientists, such as reservoir engineers and petrophysicists, get the full benefit of the course. However, it would be particularly suitable for geoscientists working on fluvial/deltaic exploration and production projects, to show how common stratigraphic and structural variations can impact reservoir performance.
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:
- Divide subsurface reservoirs into flow units that capture key reservoir flow characteristics and heterogeneities at a variety of reservoir model scales.
- Communicate and discuss flow unit properties between subsurface team disciplines.
- Understand detailed facies analysis within deposits of wave dominated deltas, fluvial dominated deltas, fluvial systems, tidal / estuarine, eolian and turbidites.
- Recognition of key facies in cores and logs.
- Use key sequence stratigraphic concepts in a practical and predictive way.
Course Content
This course emphasizes:
- An overview of facies associated with:
- fluvial and wave dominated deltas
- fluvial systems
- eolian deposits
- tidally influenced shoreline deposits
- turbidites
- lacustrine
- incised valley fill
- Sequence stratigraphic concepts including:
- sequences and parasequences
- sequence boundaries
- flooding surfaces and transgressive surfaces of erosion
- Structural heterogeneities, such as:
- fractures, deformation bands and fault seal
Course lectures and exercises provide participants with an awareness of reservoir architecture in a variety of stratigraphic and structural settings. Depositional environments studied in outcrops include deltaic, eolian, fluvial, turbidites, tidal, lacustrine and coastal plain. Emphasis is placed on understanding reservoir geometry and fluid flow characteristics (i.e. connectivity, Kv, Kv/Kh) in the various reservoir facies studied. Outcrops are also used to demonstrate field and reservoir scale structural heterogeneities.
Outcrop exercises are used to demonstrate: (a) recognition of facies using sedimentology; (b) reservoir geometries; (c) subdivision of reservoirs into flow units; (d) variations in Kv and Kv/Kh of flow units; (e) key stratigraphic surfaces; (f) impact of stratigraphic and structural heterogeneities on reservoir fluid flow at a production well spacing interval; and (g) what needs to be captured in geologic models.
A practical approach to using sequence stratigraphic concepts is also presented.
Itinerary (Provisional)
Day 0
Participants arrive in Grand Junction, Colorado
Day 1
- Morning lectures
- Fieldwork west of Grand Junction looking at outcrops of lacustrine, fluvial and eolian formations.
- Discussions about basin history, geochemistry and fractures.
Overnight in Grand Junction, Colorado
Day 2
- Morning review
- Marine parasequences and wave dominated deltas
- Meandering fluvial
Overnight in Green River, Utah
Day 3
- Turbidites
- Sequence boundaries and incised valley fill
- Parasequence correlation
- Recognition and importance of relay ramps, fault seal and deformation bands
Overnight in Green River, Utah
Day 4
- Fluvial dominated deltas
- Growth faults
- Tidal deposits
Overnight in Green River, Utah
Day 5
- Sequence boundaries and incised valley fill
- Parasequence correlation
- Review of concepts
Overnight in Grand Junction, Colorado
Day 6
Participants travel home
Tutor(s)
Mike Boyles: Retired Shell Oil; Affiliate Faculty, Colorado School of Mines