tuesday 21 may 2013 - keynote - mike vincent

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1 Five things you didn’t want to know about hydraulic fractures Mike Vincent [email protected] Fracwell LLC Microseismic image: SPE 119636 Why we need to frac The bad news – 5 things you didn’t want to know The good news – Compensating for some of these problems can significantly improve production and profitability! Outline

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Page 1: Tuesday 21 May 2013 - Keynote - Mike Vincent

1

Five things you didn’t want to know about hydraulic fractures

Mike Vincent

[email protected]

Fracwell

LLC

Microseismic image: SPE 119636

• Why we need to frac

• The bad news

– 5 things you didn’t want to know

• The good news

– Compensating for some of these problems can significantly improve production and profitability!

Outline

Page 2: Tuesday 21 May 2013 - Keynote - Mike Vincent

2

1. Fluid Flow Assumptions

– Can I use Darcy’s Law & published conductivity data?

2. Are fracs durable?

3. Can I simulate a reservoir as a homogeneous layer?

4. Can I model a frac as a simple vertical plane?

5. Will I reach a unique match with careful analyses?

5 Things To Investigate

Why Fracture Stimulate?

Top View

Side View

Unstimulated Wells:

Require high reservoir permeability for sufficient

hydrocarbon flow

Hydraulic Fractures:

Accumulate hydrocarbons over enormous area, achieving economic flowrates from low

permeability formations

Figures not to scale!

Page 3: Tuesday 21 May 2013 - Keynote - Mike Vincent

3

Reservoir Contact

Multi-Lateral – 15,000 ft of drilled length in 5 laterals

<24,000 ft2 of reservoir contact

Overhead, map view of 5 laterals

drilled from one wellhead.

• Propped fractures touch more rock than multi-lateral wells

• It is more cost-effective to touch rock with a fracture than with a drill bit

Tiny Frac - 20,000 lbs of proppant

Fracture Stimulated Completion: 200 ft half-length, 50 ft height

2 wings * 2 faces * 200 ft * 50 ft = 40,000 ft2 3700m2 of contact

One small transverse frac = 40,000 ft2 3700m2 of contact

Bakken = 6,000,000 ft2 560,000m2 of contact

Barnett style complex network >10,000,000 ft2 >1,000,000m2 of contact

Transversely Fractured Horizontal Wells let you Repeat this!

Page 4: Tuesday 21 May 2013 - Keynote - Mike Vincent

4

Technology Progression

0.0001

0.001

0.01

0.1

1

10

0

1

10

100

1,000

10,000

100,000

1,000,000

Perforated Vertical

Openhole Vertical

Openhole Horizontal

Biwing Fracture

Multiple Transverse Fractures

Re

se

rvo

ir P

erm

mD

Re

se

rvo

ir C

on

tac

t m

2

Reservoir Contact

Economic Gas Reservoir Perm

Economic Oil Reservoir Perm

Increasing our reservoir contact by 1,000,000 fold

has allowed pursuit of reservoirs with thousands of times lower perm

In low perm reservoirs, fractures are often

the most critical component of our

completion

However, they are the most poorly optimized element!

Page 5: Tuesday 21 May 2013 - Keynote - Mike Vincent

5

• Adequate reservoir contact (frac length)

• Adequate flow capacity (conductivity)

Two basic design goals

for fracture treatment

• Fracs

– Simple (bi-wing), planar, vertical, hydraulically continuous, highly conductive, durable

• Reservoir

– Homogenous reservoirs (or simplified layering)

• Fluid Flow

– Simple fluid flow regimes

Convenient Assumptions

Page 6: Tuesday 21 May 2013 - Keynote - Mike Vincent

6

SPE 128612

Do we envision fracs correctly?

15

We picture fracs as perfect vertical planes without restriction to hydrocarbon flow

Fracs are very narrow ribbons, massively long!

Frac length frequently

thousands of times greater than

the wellbore diameter

500

1500

7000

182

1137

5715

72

672

3481

24

225

1243

549

479

1.4

14144

0.67

130

0.3 496

0

1000

2000

3000

4000

5000

6000

7000

Eff

ecti

ve C

on

du

cti

vit

y (

md

-ft)

(D-m

)

API Test Modified 50-

Hour Test

"Inertial

Flow" with

Non-Darcy

Effects

Lower

Achieved

Width (1

lb/sq ft)

Multiphase

Flow

50% Gel

Damage

Fines

Migration /

Plugging

Cyclic

Stress

Chinese Sand

Jordan Sand

CarboLITE

Realistic Conductivity Reductions 20/40 proppants at 6000 psi

0.3

0.6

0.9

1.2

2.1

1.5

1.8

0.0001 D-m

0.001 D-m

0.029 D-m

Conditions: YM=5e6 psi, 50% gel damage, 250°F, 1 lb/ft2, 6000 psi, 250 mcfd, 1000 psi bhfp, 20 ft pay, 10 blpd

YM=34e3 MPa, 50% gel damage, 121°C, 5 kg/m2, 41 MPa, 7000 m3/d, 7 MPa bhfp, 6 m pay, 1.6 m3l/d

References: ST Sand: SPE 14133, 16415, CL: Carbo typical, LT: Stim-Lab PredK 2002, SPE 24008, 3298, 7573, 11634, CARBO Tech Rpt 99-062, Run #6542, StimLab July 2000, SPE 16912, 19091, 22850, 106301, 84306

Effective conductivities can be less than 1% of API test values

99.9% reduction

99.7% reduction

98.6% reduction

16

Page 7: Tuesday 21 May 2013 - Keynote - Mike Vincent

7

Does Conductivity Degrade?

McDaniel , SPE 15067

All published lab data show proppants continue to crush, compact, rearrange over

time and lose conductivity.

SPE 12616, 14133, 15067, 110451,128612, 134330, 136757, Hahn, Drilling Vol 47, No 6,

April 1986

Some proppants are more durable than others. But none are “constant”

Why don’t engineers recognize this?

This degradation has nothing to do with

“diagenesis”. Occurs dry, wet, mineral oil, N2

gas, between Teflon, steel, sandstone or shale

Even if fracs are perfect, wide fracs with optimal

proppant placement throughout…

Pressure losses are 50 to 1000 times higher

than we estimated!!

Now… What if the fracs are not perfect planes?

What does this mean?

Page 8: Tuesday 21 May 2013 - Keynote - Mike Vincent

8

Pollard (2005) Northeast Ship Rock Dike, New Mexico24

Relatively simple, extremely wide fracture

Extends 9500 feet at surface, average width

exceeding 7 feet!

We have created hydraulic fracs 2200 ft half-length but less than 0.1 inches wide

Pollard (2005) Northeast Ship Rock Dike25

Outcrop actually comprised of >30 discrete

echelon segments separated by intact host rock

Even this dike appeared “discontinuous” in outcrop.

Are you certain your frac is continuous?

Page 9: Tuesday 21 May 2013 - Keynote - Mike Vincent

9

Is Fracture Complexity Good or Bad?

Simple Fracture Complex Fracture

Very Complex Fracture Network

Pro:

Complex fracs increase the reservoir contact (beneficial in nano-

Darcy shales?)

Con:

Complex fracs complicate the flow path,

and provide less cumulative conductivity

than simple, wider fractures [SPE

115769,119143,144702]

SPE 7744126

NEVADA TEST SITE - HYDRAULIC FRACTURE MINEBACK

Observations of Fracture Complexity

Physical evidence of fractures nearly always

complex

Page 10: Tuesday 21 May 2013 - Keynote - Mike Vincent

10

Multiple

Fractures• Initiation At Perforations

– Multiple Perforations

Provide Multiple Entry

Points For Fracture

Initiation

– Five Separate

Fractures Are Visible

In These Fractures

Initiated From

Horizontal Wellbore

– 12 Perforations Total

• 6 Top & Bottom

I would have modeled/predicted a single frac with much

higher conductivity than 5 narrow fracs added together

[This actually is a bad outcome!]

NEVADA TEST SITEHYDRAULIC FRACTURE

MINEBACK

Multiple Strands in a Propped Fracture

(Vertical Well)

These fractures are narrow, you are looking at an angle to the exposed frac face

Page 11: Tuesday 21 May 2013 - Keynote - Mike Vincent

11

Mesaverde MWX test, SPE 22876

Physical evidence of fractures nearly always

complex

Multiple Strands in a Propped Fracture(Vertical Well)

� 7100 ft TVD [2160m]

� 32 Fracture Strands Over 4 Ft Interval

� HPG gel residue on all surfaces

� Gel glued some core together (>6 yrs elapsed post-frac!)

� All observed frac sand (20/40 RCS) pulverized <200 mesh

� A second fractured zone with 8 vertical fractures in 3 ft interval observed 60 feet away (horizontally)30

Is complexity solely attributed to “rock fabric”?

Many other examples! [TerraTek, Baker, Weijers, CSM FAST consortium]

Unconsolidated 200 mesh sand, 35 lb XLG,Flow � SPE 63233

Chudnovsky, Univ of Ill, Chicago

32

Page 12: Tuesday 21 May 2013 - Keynote - Mike Vincent

12

Physical evidence of fractures nearly always complex

NEVADA TEST SITEHYDRAULIC FRACTURE

MINEBACK

Fracture Complexity in Vertical direction

Laminated on every scale?

34

Figure 2 – On every scale, formations may have laminations that hinder vertical permeability and fracture penetration. Shown are thin laminations in the Middle Bakken [LeFever 2005], layering in the Woodford [outcrop photo courtesy of

Halliburton], and large scale laminations in the Niobrara [outcrop and seismic images courtesy of Noble]

SPE 146376

Page 13: Tuesday 21 May 2013 - Keynote - Mike Vincent

13

Woodford Shale Outcrop

Will frac complexity change my understanding of required frac design?

Narrower aperture plus significantly higher stress in

horizontal steps?

Failure to breach all laminae?

Will I lose this connection due to

crushing of proppant in horizontal step?

Our understanding of frac barriers and kv should

influence everything from lateral depth to frac fluid type, to implementation

Fractures Intersecting Stacked Laterals

Modified from Archie Taylor SPE ATW – Aug 4 2010 36

23 ft thick Lower Bakken Shale

Frac’ed Three Forks well ~1MM lb proppant in 10 stages

1 yr later drilled overlying well in Middle Bakken; Kv<0.000,000,01D (<0.01 µD)

kv/kh~0.00025 even after fracing!

Lateral separation 250 feet at

toe/heel, crossing in middle

Inability to create an effective, durable fracture 30 feet tall?!

Drill redundant well in each interval since frac has inadequate vertical penetration/conductivity?!

Bakken – Three Forks

Page 14: Tuesday 21 May 2013 - Keynote - Mike Vincent

14

Continuity Loss

Necessitates vertical downspacing?

“Array Fracturing” or “Vertical Downspacing” Image from CLR Investor Presentation, Continental, 201237

A number of operators are investigating “vertical downspacing” in the Bakken petroleum system. Similar efforts underway in Niobrara, Woodford, Montney and Permian

formations.

Is it possible that some number of these expensive wells could be unnecessary if fractures were redesigned?

Uniform Packing Arrangement?

Is this ribbon laterally

extensive and continuous

for hundreds of meters as

we model?

40

Pinch out, proppant

pillars, irregular

distribution?

A simulator may predict

this is sufficient!

Page 15: Tuesday 21 May 2013 - Keynote - Mike Vincent

15

With what certainty can we explain this production?

SPE 106151 Fig 13 – Production can be matched with a variety of fracture and reservoir parameters41

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 100 200 300 400 500 600

Production Days

Sta

ge

Pro

du

ction

(m

cfd

)

0

20

40

60

80

100

120

140

160

180

200

Cu

mu

lative

Pro

du

ction

(M

Mscf)

Actual Production Data

Nice match to measured microseismic, eh?

SPE 106151 Fig 13 – Production can be matched with a variety of fracture and reservoir parameters42

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 100 200 300 400 500 600

Production Days

Sta

ge

Pro

du

ction

(m

cfd

)

0

20

40

60

80

100

120

140

160

180

200

Cu

mu

lative

Pro

du

ction

(M

Mscf)

Actual production data

Long Frac, Low Conductivity 500' Xf, 20 md-ft, 0.5 uD perm, 23 Acres 4:1 aspect ratio

Page 16: Tuesday 21 May 2013 - Keynote - Mike Vincent

16

Is this more accurate? Tied to core perm

SPE 106151 Fig 13 – Production can be matched with a variety of fracture and reservoir parameters43

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 100 200 300 400 500 600

Production Days

Sta

ge

Pro

du

ction

(m

cfd

)

0

20

40

60

80

100

120

140

160

180

200

Cu

mu

lative

Pro

du

ction

(M

Mscf)

Actual production data

Long Frac, Low Conductivity

Medium Frac, Low Conductivity

500' Xf, 20 md-ft, 0.5 uD perm, 23 Acres 4:1 aspect ratio

100' Xf, 20 md-ft, 5 uD perm, 11 Acres 4:1 aspect ratio

Can I reinforce my misconceptions?

SPE 106151 Fig 13 – Production can be matched with a variety of fracture and reservoir parameters44

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 100 200 300 400 500 600

Production Days

Sta

ge

Pro

du

ction

(m

cfd

)

0

20

40

60

80

100

120

140

160

180

200

Cu

mu

lative

Pro

du

ction

(M

Mscf)

Actual production data

Long Frac, Low Conductivity

Medium Frac, Low Conductivity

Short Frac, High Conductivity, Reservoir Boundaries

500' Xf, 20 md-ft, 0.5 uD perm, 23 Acres 4:1 aspect ratio

100' Xf, 20 md-ft, 5 uD perm, 11 Acres 4:1 aspect ratio

50' Xf, 6000 md-ft, 10 uD perm, 7 Acres 4:1 aspect ratio

• History matching of production is surprisingly non-unique.

• Too many “knobs” available to tweak

• We can always blame it on the geology

Even if I “know” it is a simple planar frac, I cannot prove whether it was inadequate reservoir quality, or

inadequate completion with a single well

Page 17: Tuesday 21 May 2013 - Keynote - Mike Vincent

17

1. Complex Flow Regimes

– 100x higher pressure losses

2. Conductivity Degrades

3. Heterogeneous Reservoirs

– Dependant on fracs to connect reserves

4. Complex Frac Geometry

– Require commensurate increase in conductivity

5. Non-unique interpretations

5 Things You Didn’t Want to Know

Removing the Uncertainty

• If we require a production match of two different frac designs, we remove many degrees of freedom

– lock in all the “reservoir knobs”!

– Attempt to explain the production results from initial frac AND refrac

• 143 published trials in SPE 134330

• 100 Bakken refracs 136757

– Require simultaneous match of two different frac designs in same reservoir!

• 200+ trials in SPE 11914346

Page 18: Tuesday 21 May 2013 - Keynote - Mike Vincent

18

Field Studies Documenting Production Impact

with Increased Fracture Conductivity>200 published studies identified,

authored by >150 companies

SPE 119143 tabulates over 200 field studies

Oil wells, gas wells, lean and rich condensateCarbonate, Sandstone, Shale, and Coal

Well Rates Well Depths

1 to 25,000 bopd 100 to 20,000 feet0.25-100 MMSCFD

47

Production Benefit

• In >200 published studies and hundreds of unpublished proppant selection studies,

• Operators frequently report greater benefit than expected using:– Higher proppant concentrations (if crosslinked)

– More aggressive ramps, smaller pads– Screen outs (if sufficiently strong proppant)

– Larger diameter proppant– Stronger proppant– Higher quality proppant– More uniformly shaped & sized proppant

• Frac conductivity appears to be much more important than our models or intuition predict!

A tabulation of 200 papers in SPE 11914349

Page 19: Tuesday 21 May 2013 - Keynote - Mike Vincent

19

We are 99.9% certain the Pinedale Anticline

was constrained by proppant quality

Effect of Proppant Selection upon Production

0

100

200

300

400

500

600

700

800

900

LL3

LL2

LL1

MV5

MV4

MV3

MV2

MV1

MV0

Avera

ge

Reservoir Sub-Interval (Lower Lance and Mesa Verde)

Pro

duction R

ate

100 d

ays p

ost-

frac (

mcfd

)

Versaprop

CarboProp

ISP-BS

ISP 20/40

Averages based on 95 stages ISP-BS and 54 stages ISP 20/40

SPE 106151 and 108991

70% increase in productivity achieved with

a more uniformly

sized proppant!

Can we learn from refracs?

Pagano, 2006

– Gas Condensate wells in DJ Basin – up to 5 restimulations

Page 20: Tuesday 21 May 2013 - Keynote - Mike Vincent

20

Increase Conductivity in Refracs?Dozens of examples in literature

Shaefer, 2006 – 17 years later,

tight gas

0

500

1000

1500

2000

2500

3000

3500

Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01

Gas R

ate

, M

CF

D

0

50

100

150

200

250

300

350

400

450

500

Wate

r R

ate

, B

WP

D

Gas

Water

Initial Frac in

1989:

48,000 lb 40/70

sand + 466,000

lb 12/20 sand

May 1999 Frac:

300,000 lb 20/40

LWC

May 1995 Frac:

5,000 lb 100 mesh

+ 24,000 lb 20/40

Sand

Vincent, 2002 – 9 years later,

CBM

0

500

1000

1500

2000

2500

3000

3500

4000

May-84 May-86 May-88 May-90 May-92 May-94 May-96 May-98 May-00

Date

Pro

du

cti

on

fro

m F

rac

ture

(b

fpd

) Original Fracture (20/40 Sand)

Phase I refrac (20/40 Sand)

Phase III refrac (16/20 LWC)

Incremental Oil Exceeds

1,000,000

barrels

Incremental

Oil exceeds650,000 barrels

First Refrac

Second Refrac

Pospisil, 1992 – 6 years later,

20 mD oil

0

500

1000

1500

2000

2500

Sta

biliz

ed

Ra

te (

MS

CF

D)

Pre Frac 10,000 gal

3% acid +

10,000 lb

glass beads

80,000 gal +

100,000 lb

20/40 sand

75,000 gal +

120,000 lb

20/40 ISP

Ennis, 1989 – sequential

refracs, tight gas

020406080100120 Well A Well B Well C Well D Well EProduction Rate (tonnes/day) .. Initial FracRefracDedurin, 2008, Volga-Urals

oil

52

If this is not compelling…

Is there additional irrefutable

evidence that our fracs are not

as effective as we thought?

Page 21: Tuesday 21 May 2013 - Keynote - Mike Vincent

21

Offset wells (orange)

perfed at same depth

loaded with frac fluid

After unloading fluid,

several offset wells

permanently stimulated

by treatment!

Fractures Intersecting Offset Wellbores

-3000

-2500

-2000

-1500

-1000

-500

0

500

1000

1500

-1000 -500 0 500 1000 1500 2000 2500 3000

West-East (ft)

So

uth

-No

rth

(ft

)

Observation

Well

Barnett Shale

SPE 7744154

Evidence frac’ed into offset wells (at same depth)

Microseismic mapping

Slurry to surface

Increased watercut

Solid radioactive tracer (logging)

Noise in offset monitor well

Documented inTight sandstone (Piceance, Jonah, Cotton

Valley, Codell)High perm sandstone (Prudhoe)

Shale (Barnett, Marcellus, Muskwa, EF)

Dolomite (Middle Bakken)Chalk (Dan)

Often EUR, “pulse tests” “interference tests” fail to indicate sustained hydraulic

connectivity!

-2000

-1800

-1600

-1400

-1200

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

1200

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-1500

-1300

-1100

-900

-700

-500

-300

-100

100

300

500

700

900

1100

1300

1500

West-East (ft)

So

uth

-No

rth

(ft

)

1st Stage 2nd Stage

= First Stage Perf Clusters

= 2nd Stage Initial Perf Clusters

= Revised 2nd Stage Perf Clusters

Observation Well

Treatment Well

3000’ x 2900’

Two Stage Cemented Barnett Shale Lateral

SPE 90051

9 million square feet >200 acres

Page 22: Tuesday 21 May 2013 - Keynote - Mike Vincent

22

How far do we drain? Barnett Infill Drilling

Source: Brian Posehn, EnCana, CSUG April 28, 2009

When operators have infill drilled on

385’ avg

spacing

Infill wells “steal” 6% of parent

EUR

Infill wells produce 80% of

parent EUR

• Sometimes adjacent wells are improved by bashing!

Fractures Intersecting Bakken Laterals

Enerplus SPE 139774 – Jan 2011

Well spacing ~1250 ft. Communication at 2500 ft

30/50 MgLite, 8 BASS stages @150klbs

Borate XL fluid to 5-6 ppg at tail

Page 23: Tuesday 21 May 2013 - Keynote - Mike Vincent

23

Horn River, BC – SPE 140654

Horn River, BC Microseismic Map

We can “bash” offset laterals at 5000 ft spacing with frac water.

Sometimes we miss laterals in between.

This map is not assurance that we have drained all the hydrocarbons in the well

vicinity!!!

Source: esgsolutions.com

Page 24: Tuesday 21 May 2013 - Keynote - Mike Vincent

24

How far do we drain? Ante Creek, Montney Oil

Source: ARC Investor Presentation Nov 2012

16 years later encountering near-virgin pressure.

Demonstrates that initial wells were insufficient

to recover all available reserves.

Is this due solely to reservoir

discontinuity? Well locations?

Frac insufficiency?

Marcellus Fractures Intersecting Offset Laterals

Mayerhofer SPE 145463 – Nov 2011

Marcellus - Slickwater

Microseismic, DFITS, downhole pressure

gauges, PTA, chemical tracers, production

interference

950 ft spacing. 1H treated 5 weeks after 2H

Cemented, 7 stage PnP

Slickwater 100 mesh, 40/70 and 30/50 sand

~6000 ft TVD

Pressure communication in 6 of 7 stages

Chem tracers from 2,3,5,6,7 recovered in 2H

When one well is shut in, the other well

increases in rate by ~20% demonstrating

some degree of connection, but clearly imperfect after 6 months. Large pressure losses inside the

fractures. Can we fix this?

Page 25: Tuesday 21 May 2013 - Keynote - Mike Vincent

25

• SPE 140463 – Edwards, Weisser, Jackson, Marcotte– All diagnostics (microseismic, chemical tracers, surface pressure

gauges, etc) indicate fracturing treatments interact.

– Well-to-well connection while the reservoir is dilated with frac fluid.

– Microseismic suggests lengths >1000 ft

– Production analysis estimates ~150 ft effective half length after 6 months

– However, wells drilled on 500 ft spacing are similar in productivity to those on 1000 ft spacing, suggesting they are not competing for reserves

Marcellus – Wells on 500 ft spacing do not

appear to share reserves

Any new opportunities to learn

something on a single well?

Page 26: Tuesday 21 May 2013 - Keynote - Mike Vincent

26

Horizontal Well - Production Log

0

5

10

15

20

15 14 13 12 11 10 9 8 7 6 5 4 3 2

Pe

rce

nt

Co

ntr

ibu

tio

n

Stage Number toeheel

Stages 2,7,13 screened out, average contribution = 13.5%Stage 1 could not be accessed, Stages 3 and 4 were unpropped

Average contribution others (omitting 3&4 unpropped)= 6.3%Stage 10, frac fluid volume reduced by 25% (more aggressive)

Intentional Screenouts?

• Probable advantages to screenouts• Wider frac (more net pressure)

• Better connection to wellbore

• Treatment diversion into other perforation clusters

• Reduced proppant flowback

• A screened-out fracture may be “immune” to subsequent overdisplacement when pumping plug/dropping ball

• May be “immune” to subsequent refrac injection?

• Perhaps advantage is simply avoiding overflush?

• Disadvantages to screenouts• Standby time and cost to cleanout/flowback

• Higher pressures may induce more gel damage

• Stress on equipment and tubulars during treatment

• Higher stress must be borne by proppant

• Never screenout wells with ULWP or deformable proppant

• May crush cleats in CBM, delicate formations

• High net pressure may induce unwanted height growth, sacrificing propped length

Page 27: Tuesday 21 May 2013 - Keynote - Mike Vincent

27

• Most statistically valid field trial published in industry– Pinedale Anticline, tight gas ~5 microDarcy, vertical wells

• Between 2 and 15% of the stages screenout depending on depth/stress/proppant type

• 5 stages screened out with sand or RCS– Only 1 provided acceptable Q100 rates.

– 4 were extremely disappointing

• Stages that screened out on ceramic were very productive– Every ISP screenout was 1st or 2nd most productive stage in well

– Effective frac lengths: 10 of 11 ceramic screenouts in upper 50%. 11th

was in upper 55%...

• Screenouts are NOT beneficial in all situations. Careful evaluation is needed.

SPE 106151

1) Incredible reservoir contact provided by hydraulic fractures

2) Bad News: At least 5 reasons fracs are not optimized

– Fluid flow is complicated

– Conductivity degrades. Many fractures collapse or heal

– Heterogeneous reservoirs depend on frac continuity

– Frac geometry is tortuous, often with poor connection between the frac and wellbore

– Typical interpretations are NOT unique

3) Great News: Fracs are not optimized

– Reservoirs are often capable of tremendous increases in productivity with improved frac design

Summary 1 of 2

Page 28: Tuesday 21 May 2013 - Keynote - Mike Vincent

28

Take home messages to optimize frac productivity

– All these “complexities” compromise flow capacity

– You need much more conductivity than you think!

– Be wary of modeling, intuition, or conventional wisdom

– Experiment and validate

– Keep searching for a better completion. We are NOT optimized!

– Focus on fracture EFFECTIVENESS, not dimensions

– Horizontal wells provide some unique data gathering opportunities!

Summary 2 of 2

Page 29: Tuesday 21 May 2013 - Keynote - Mike Vincent

Available Seminars

• Conventional versus Unconventional Reservoirs • Myths and Misunderstandings that hinder Frac Optimization • Detailed Rock Mechanics, Fluid Rheology, and Propagation Theory • Physics of Fluid Flow • Frac Sand mining and QC, Ceramic manufacturing and QC • Proppant Types, Characteristics – Understanding the differences between sand, resin and

ceramic • Conductivity Testing • Non-Darcy Flow • Multiphase Flow • Understanding Proppant Crush Testing - Are hot/wet crush tests superior? • Other Issues - Embedment, Stress Cyclic, Elevated Temperature • Determining Realistic Proppant Conductivity • Field Results – 200 summarized on SPE 119143; ~30 in PowerPoint • PTA / Well Testing considerations / Effective Frac Lengths • Fines Migration & Plugging • Significance of Proppant Density, Frac width, sieve distribution upon proppant value • Gel Cleanup

– Lab studies and field examples documenting load recovery • Proppant Flowback and Erosive Potential of sand, ceramic, and resin-coated proppants • Frac Pack concepts and field studies • Zero Stress applications – Flow in wellbore annuli or packed perforations • Frac Optimization

– CBM frac optimization – Fracturing Carbonates – Where do unpropped fractures work?

• Horizontal Wells – Comparisons with Vertical Fractured Completions • Specific Field Results (Pinedale, Kuparuk, Cardium, Wamsutter, Birch Creek, Siberia,

Cotton Valley, Vicksburg, Haynesville Lime, UP + Ranger, others) • Bakken Horizontal Wells – Importance of Frac Intersection with Wellbore • Performance under Severe Conditions (Steam, Acid) + Diagenesis • Waterfracs/Slickwater Fracturing • Frac Geometry – What do Fracs Really look like? What errors are we making? • 100 mesh sand – pros & cons • Refracturing

Mike Vincent

Insight Consulting

[email protected]

303 568 0695