American Oil and Gas Reporter - June 2022 - 58

SpecialReport: Permian Comeback Kings
Figure 1 shows near-wellbore
DAS/DTS and treatment data (from top
to bottom) in time-synchronized panels
for 7 stages with operational issues on
Boxwood-4H. With the start of injection
on the stage, DAS clearly showed highenergy
signal responses indicated by
warmer colors and corresponding to fluid
and proppant placement for the six PCs,
annotated as 7.1 to 7.6 from toe to heel.
The DAS energy signals remained active
for all clusters until the end of the
treatment, when the pumps were shut
down. Because fracturing fluid was injected
with a relatively lower temperature,
the DTS temperature waterfall map in
the middle showed a cooling effect, indicated
by cooler colors in the near-wellbore
region during the treatment of the six
PCs, followed by a warming effect shortly
after the end of treatment.
The integrated analysis of near-wellbore
DAS/DTS and treatment data can be used
to better understand the adverse impacts
of completion operational issues. These
operational issues can include plug failures,
poor cement bonding behind casing, operational
challenges leading to mid-stage
shutdowns and others.
Operational efficiency is critical to
ensuring proper placement of the fracturing
treatment within a given stage. All the
PCs in Stage 6 received treatment early
in the stage, as evidenced by high DAS
energy signals (Figure 1A). When pumping
resumed after the mid-stage shutdown
caused by a pump reliability issue, DAS
energy signals were clearly lost for a
single heel PC, which remained inactive
during the rest of the treatment, while
the other PCs remained active and may
have taken additional fluid and proppant
beyond the designed amounts.
Figures 1B and C show the lack of
isolation during the treatments of Stage
8 and Stage 11 based on clear DAS/DTS
responses in the previous stages. Specifically,
the DAS/DTS response lag in
Stage 7 during the treatment of Stage 8
indicates flow behind casing, potentially
attributable to poor cement bonding or a
longitudinal fracture connection. Alternatively,
the immediate and stronger
DAS/DTS response in Stage 10 when
FIGURE 1
Near-Wellbore DAS/DTS and Treatment Data for Seven Boxwood-4H Stages with Operational Issues
(Red Cross = Plug Location)
Stg 6
DAS signal lost for heel
cluster after pump restored.
Stg 8
Stg 7
Stg 6
Stg 8
Stg 7
Cool-down
Cool-down
A) Stage 6 (6x18): mid-stage shutdown (87% prop. placement)
B) Stage 8 (6x18): stage isolation issue (100% prop. placement)
Stg 11
Stg 10
Stg 11
Stg 10
Cool-down
Cool-down
One cluster became
inactive in later stage.
Stg 16
Stg 16
Reduced Slurry Rate
C) Stage 11 (6x15): stage isolation issue (62% prop. placement)
D) Stage 16 (6x12): reduced frac job size (16% prop. placement)
Stg 18
Weak DAS signal for
least two clusters
Stg 22
No DAS signal for at
least two clusters
Stg 18
Stg 22
Reduced Slurry Rate
E) Stage 18 (6x12): mid-stage shutdown (98% prop. placement)
F) Stage 22 (10x20): reduced frac job size (81% prop. placement)
58 THE AMERICAN OIL & GAS REPORTER

American Oil and Gas Reporter - June 2022

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