FracPac
Conductivity Logic
Why Not Denser Proppants?
Side View of Frac
Attempt to create a frac of length Lf
to stimulate productivity.
Net Pay
Lf
Top View of Frac
Width
Lf
• Created width is proportional to
net pressure increase.
• Net pressure increase is
independent of proppant selection.
• The proppant is used to fill the
created fracture.
• Created fracture width and
proppant selection determines
conductivity.
• Effective fracture half-length is a
function of dimensionless
conductivity (eff Lf = wkf/31.4k).
• Therefore stimulation effectiveness
is proportional to conductivity.
• Can proppant selection change
stimulation effectiveness?
Comparison of Conductivities
CONDUCTIVITY (md-ft)
Closure Stress
psi
20/40 LW Ceramic
12.0 lb/sq ft-200˚F
20/40 InterProp®
12.0 lb/sq ft-200˚F
20/40 Sintered Bauxite
12.0 lb/sq ft-200˚F
2,000
36,995
36,672
38,795
4,000
30,568
31,195
32,527
6,000
21,848
23,188
27,194
8,000
13,349
18,292
21,688
10,000
8,225
14,610
15,693
12,000
4,371
10,718
11,175
0.646
0.662
0.662
1.3892
1.1207
1.0848
Median Diameter
(mm)
Actual Width
Comparison of Conductivities
CONDUCTIVITY (md-ft)
Closure Stress
(psi)
20/40
LW
Ceramic
12.0 lb/sq ft200˚F
20/40
InterProp®
12.0 lb/sq ft200˚F
20/40
Sintered Bauxite
12.0 lb/sq ft200˚F
2,000
36,995
36,672
38,795
4,000
30,568
31,195
32,527
6,000
21,848
23,188
27,194
8,000
13,349
18,292
21,688
10,000
8,225
14,610
15,693
12,000
4,371
10,718
11,175
Median
Diameter (mm)
0.646
0.662
0.662
Actual Width
1.3892
1.1207
1.0848
• Proppant conductivities at
consistent concentrations indicate
that more dense/higher strength
proppants have significantly
higher conductivities only at
stresses above 6,000 psi.
• Actual width shown at the bottom
of the chart is for 4,000 psi
closure, indicating that there is
substantially more width required
to hold 12#/ft2 of lightweight
proppant versus more
dense proppant.
• If we hold the created width
constant and then look at
conductivity achieved, we
will get a true comparison
of conductivity.
True Comparison of Conductivities
CONDUCTIVITY (md-ft)
Closure Stress
psi
20/40 LW Ceramic
12.0 lb/sq ft-200˚F
20/40 InterProp®
14.9 lb/sq ft-200˚F
20/40 Sintered Bauxite
15.4 lb/sq ft-200˚F
2,000
36,995
45,677
50,033
4,000
30,568
38,854
41,949
6,000
21,848
28,882
35,071
8,000
13,349
22,784
27,970
10,000
8,225
18,198
20,238
12,000
4,371
13,349
14,413
0.646
0.662
0.662
1.3892
1.3888
1.3894
0.00037
0.00029
0.00026
Median Diameter
(mm)
Actual Width
Beta (atm^2/g)
True Comparison of Conductivities
CONDUCTIVITY (md-ft)
Closure
Stress
psi
20/40 LW
Ceramic
12.0lb/sqft-200˚F
20/40 InterProp®
14.9lb/sqft-200˚F
20/40 Sintered
Bauxite
15.4lb/sqft-200˚F
2,000
36,995
45,677
50,033
4,000
30,568
38,854
41,949
6,000
21,848
28,882
35,071
8,000
13,349
22,784
27,970
10,000
8,225
18,198
20,238
12,000
4,371
13,349
14,413
0.646
0.662
0.662
Actual
Width
1.3892
1.3888
1.3894
Beta (atm2/g)
0.00037
0.00029
0.00026
Median Dia.
(mm)
• When we compare
conductivities for
equal widths between
the proppant types, we
find that at 4,000 psi
closure stress,
InterProp has 27%
more conductivity
than EconoProp
and Sintered Bauxite
has 37% more
conductivity than
EconoProp.
True Comparison of Conductivities
CONDUCTIVITY (md-ft)
Closure
Stress
psi
20/40 LW
Ceramic
12.0 lb/sq ft200˚F
20/40 InterProp®
14.9 lb/sq ft-200˚F
20/40 Sintered
Bauxite
15.4 lb/sq ft-200˚F
2,000
36,995
45,677
50,033
4,000
30,568
38,854
41,949
6,000
21,848
28,882
35,071
8,000
13,349
22,784
27,970
10,000
8,225
18,198
20,238
12,000
4,371
13,349
14,413
Median
Diameter (mm)
0.646
0.662
0.662
Actual Width
1.3892
1.3888
1.3894
0.00037
0.00029
0.00026
Beta
(atm^2/g)
• Beta factor for
each of the more
dense proppants is
lower, significantly
reducing the effects
of non-Darcy flow,
by 21% for InterProp
and 30% for Sintered
Bauxite.
Productivity Enhancement
114%
112%
110%
Productivity, Percentage
108%
106%
104%
102%
100%
98%
96%
94%
92%
100 md - LW
Ceramic
100 md InterProp
100 md - Bauxite
10 md - LW
Ceramic
10 md - InterProp
10 md - Bauxite
Benefits Summary
• Denser proppants provide more conductivity for a
created fracture width than lightweight proppants.
• With higher conductivity comes greater stimulation
effectiveness and increased productivity.
• Beta factors are also significantly reduced using
more dense proppants.
• Tight annular pack due to increased settling rate.
• Reduces the chance for void spaces above sump packer.
• Less susceptible to grain shifting and bed fluidization.
Why not denser proppants for FracPac operations?