A. S. Wylie, Jr. and J. R. Wood

Michigan Technological University

Permeability and Porosity Imaging of a Niagaran Reef

Per

mea

bil

ity

[md

]

30

0

Niagaran Reef TrendField Location

Gill (1977)

Belle River Mills

Niagaran Reef – Generalized Facies

Time Surface ? Debatable

after Gill (1977)

Salina Evaporite and Carbonate Units Enclose Reefs

500 ft

500 ft

VE 2X

MAP(next)

STROMATOLITE

BOUNDSTONE

WACKESTONE

REEFCONGLOMERATE

Belle River Mills Structure Map

Top Reef

CI: 50 ft

10 11

14

0.5 mile

-1900

-1600

N

Maximum height400 ft above

Non-reef BrownNiagaran

XSEC

Cored Well (34 total)

Reef Rubble Well

Reef Well

Deviated well

Niagaran StratigraphyBelle River Mills –Rock Types

Gill (1977)

MAP(previous)

Rock Type Color Codes

Avg-9.4% (1824)

Avg-10.7% (761)

Avg-79 md(1824)

[231, 100-7000]

Avg-260 md (2259)

[416, 100-7000]

Avg-11 md (761)

[13, 100-7000]

Avg-9.9 (177)

Core – Porosity & Permeability (all samples in Reef by Rock Type)

Gill (1977)

Number ofsamples

(###)

0 35 0

0

0

0

0

0 35

35

35

100

100

100

Avg-10.7% (2259)

0 100

Avg-48 md(177)

[22, 100-7000]

0.10

1.00

10.00

100.00

1000.00

10000.00

0.00 10.00 20.00 30.00

0.10

1.00

10.00

100.00

1000.00

10000.00

0.00 10.00 20.00 30.00

0.10

1.00

10.00

100.00

1000.00

10000.00

0.00 10.00 20.00 30.00

0.10

1.00

10.00

100.00

1000.00

10000.00

0.00 10.00 20.00 30.00

Core Phi vs. Perm – By Rock TypeSTROMATOLITE

CONGLOMERATE

WACKESTONE

BOUNDSTONE

Per

mea

bilit

y (m

d)

Porosity (%)

n=761

n=2259

n=1824

n=177

Visualization Orientation – 2D and 3D example views

Vertical Exaggeration (VE) – 1X to 10X

Visualization Animation Example – Permeability 25 – 30+ millidarciesStromatolite

Conglomerate

Wackestone

Boundstone

non-reef Niagaran

cored interval

VE10X

Reef Permeability Cumulative Percent – all samples

30 md (70%)

Core Permeability (millidarcies)

Per

cen

t

4980samples

> 30 mdRESET to 30 md

Reef Permeability – By Rock Type30 md (70%)

Core Permeability (millidarcies)

Per

cen

t

4980samples

> 30 mdRESET to 30 md

Permeability Distributionred voxels are 27 – 30+ millidarcies

Many other methods for modeling permeability VE10X

Log Curve Amplitude Slicing - Review

Top Reef

Base Reef,

Time-surface (?)

– Any regularly sampled data from boreholes

– One or more correlative, bounding time-surfaces

WEST EAST

(e.g. Log or Core curve data)

0.5

SLICES

250 ft

Niagaran Core – One Permeability Slice31 Wells Slicing Bottom Up

Belle River Mills Reef Limit

N

1 mile Well/Core Control PointContour Interval 4 millidarcies

0 100md

23672PERMCURVE

SLICE175

23672(log scale)

Zero PermBoundary

Niagaran Core Permeability Animation31 Wells Slicing Bottom Up

Belle River Mills Reef Limit

N1 mile Well/Core Control Point

Contour Interval 4 millidarcies

0 100md23672

(log scale)

Reef Porosity – By Rock TypeCumulative Percent

Core Porosity (%)

Per

cen

t

4980samples

Niagaran Core – One Porosity Slice31 Wells Slicing Bottom Up

Belle River Mills Reef Limit

1 mile Well/Core Control PointContour Interval 4% porosity

N

PHI0 20%

23672

SLICE175

23672PHI

CURVE

Zero PhiBoundary

Niagaran Core Porosity Animation31 Wells Slicing Bottom Up

Belle River Mills Reef Limit

1 mile Well/Core Control PointContour Interval 4% porosity

N

PHI0 20%

23672

Key Trends – Core Perm, Core Phi & GR

Slice145

Gamma RayCore PorosityCore Permeability

Slice 324

WACKESTONE

UppermostBOUNDSTONE

more control wells

What can we do with these models ?

2D and 3D Visualization aids interpretation of Permeability and Porosity Trends

in the Reef

Better targeting analysis for vertical and horizontal wells

VE10X

( 25+ md )

Perforated Intervals versus Permeability 20 - 30+ md

Perforated interval (original)VE10X

Improved completions, secondary, and tertiary projects

Best Storage versus Best Deliverability

BEST POROSITY BEST PERMEABILITY

Perforated interval( > 13% ) ( 25+ md )

VE10X

Storage and Deliverability vs. Rock Type

BEST POROSITY BEST PERMEABILITY

Rock Types( > 13% ) ( 25+ md )

VE10X

• Location of best porosity (storage capacity) and best permeability (deliverability) does not always coincide in the reservoir (reef)

• Existing well data used to model reservoir porosity and permeability distribution

• Methodology uses affordable software

Results/Conclusions