American Oil and Gas Reporter - January 2015 - 124

JANUARY 2015
FIGURE 6
Normalized Production Rate (boe/d/1,000 feet) versus Normalized Time (Left)
And Normalized Cumulative Production (Mboe/1,000 feet) versus Normalized Time (Right)
35
Normalized Cumulative Production
(Mboe/1,000')

Normalized Production Rate
(boe/d/1,000')

1,000

100

30
25
20
15
10
5
0

100

150

200

250

100

Combo Design

Conventional Design

factors. Late-time production for combo
wells was not included in the forecast
since there were not enough data to establish a decline profile. The uplift in
EUR as a result of the completion design
change was estimated at 42 percent. SRV
depletion corresponding to pressure depletion inside the enhanced zone was estimated for each well and averaged for
the pad. The SRV created with the combo
design was 71 percent higher for the average of all wells on the same pad compared with the benchmark design.
The difference in EURs estimated by
DCA and the analytical reservoir simulation model was 3 percent, while DCA
values were conservative. Considering
that these analyses were done independently, small variation in results increases
confidence in the EURs forecast. The
performance uplift varied across the
acreage from 10 to 40 percent.
It is not surprising that stimulation
design alone is not the only driver for

Combo Design

unlocking the resource potential of the
Eagle Ford Shale. Depending on reservoir
rock and fluid, well response to the same
type of completion change can be different.
Optimizing the completion design is a
dynamic process, and it is of paramount
importance to be flexible and proactive
in making design changes based on the
analysis.
With a comprehensive approach to
evaluate key completion parameters and
set a foundation to develop a dynamic
optimization workflow, Pioneer's Eagle
Ford completion design continues to
evolve. In fact, the results of the completion optimization plan are being used in
conjunction with fracture simulator modeling, microseismic analysis, reservoir
modeling (history matching, variable
SRV calculations, etc.), well interference
tests and tracers to answer the important
well spacing questions.
Figure 7 shows the reservoir performance analysis workflow. Given the results

FIGURE 7
Reservoir Performance Analysis Workflow and Results
Reservoir Performance Analysis

Diagnostic Plots and DCA

Diagnostic Plots

Comparison

rCum (% Uplift)

Lb/ft vs. Conventional

6 months: 6.5%,
12 months: 10.6%

Combo vs. Conventional

4 months: 37%

150

200

250

Normalized Time (d)

RTA and Reservoir Modeling

DCA

RTA

Reservoir Modeling

Comparison

rEUR (% Uplift)

Comparison

rSRV (% Uplift)

Comparison

Lb/ft vs. Conventional

21%

Lb/ft vs. Conventional

13%

Lb/ft vs. Conventional

11%

Combo vs. Conventional

42%

Combo vs. Conventional

71%

Combo vs. Conventional

49%

124 THE AMERICAN OIL & GAS REPORTER

rEUR (% Uplift)

Conventional Design

of the completion optimization project,
higher rates per cluster now are part of
the completion design for Pioneer's Eagle
Ford wells. Wells with higher rates per
cluster are delivering EUR increases of
about 20 percent.
The higher proppant volume and combo designs also yielded positive results
(increasing performance by 10-40 percent,
depending on the area), and also now are
part of the design in recommended areas
within the Eagle Ford.
Ì

Navitas Designs Pipeline,
Plant To Serve Eagle Ford
THE WOODLANDS, TX.-Navitas
Midstream Partners LLC says it has executed a long-term, fee-based agreement
with an investment-grade independent producer to provide gathering and processing
services in the northern Eagle Ford Shale
play in the Texas counties of Brazos and
Grimes.
According to the company, it will construct the La Bahia system, which will
consist of a 20-inch gathering line that
will deliver gas from Brazos County to
Navitas' natural gas processing plant in
Grimes County.
When completed in mid-2015, Navitas
says the cryogenic processing plant will
have a capacity of 120 million cubic feet
a day.
"Our La Bahia gathering and processing system will be state of the art, and
will provide producers a much-needed
alternative for midstream services in the
area," says R. Bruce Northcutt, president
and chief executive officer of Navitas. r

American Oil and Gas Reporter - January 2015

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