American Oil and Gas Reporter - April 2020 - 52

pages 44-49_Layout 1 4/6/2020 2:38 PM Page 52

SpecialReport: Industry Breakthroughs
FIGURE 5
Delaware Basin Wolfcamp Well Layout
2H
6H

3H
7H

geometry away from the depleted parent
well volume. The wells are laterally
spaced 600 feet apart. The 4H was monitored using the 7H sealed wellbore.
The bar chart on the 4H represent VFRs
measured using the SWPM data recorded
in the 7H, with each bar representing
the volume pumped into the treatment
well when the 7H recorded a pressure
response. Longer bars equate to more
fluid pumped before the response was
recorded on the 7H. The key take-away
from Figure 4B is that every stage in
the 4H generated a pressure response
on the 7H, suggesting that the mitigation
technique mitigated and redirected asymmetry related to depletion.
Integrating SWPM and microseismic
monitoring provided a more complete
picture of the impacts of depletion on
infill fracture geometry in the STACK.
Without SWPM, the conclusions from
microseismic would have been incomplete
and falsely indicate that hydraulic fractures
did not extend into the area of recharged
depletion, but instead extended asymmetrically away from the recharged de52 THE AMERICAN OIL & GAS REPORTER

4H
8H

12H

pletion zone. SWPM clearly showed fractures extending into the recharged depletion region. Furthermore, the coupling
of the techniques suggested different
mechanisms when infilling next to a
parent well, causing a rapid short-circuiting
through the parent fracture, where a
slower fracture propagation rate indicated
new fracture creation.
Wolfcamp Case Study
In the Delaware Basin's Wolfcamp
play, SWPM was used as part of a larger
diagnostics package designed to help improve the understanding of stage and
cluster designs in a staggered field development. SWPM was carried out in
two phases. First, the 3H and 7H were
monitored while the 12H, 4H and 8H
were zipper fractured. Second, the 2H
and 6H were monitored while the 3H
and 7H were zipper fractured. Figure 5
shows well positioning in gun barrel and
map views. Four stage/cluster designs
were evaluated:
· Design A with low clusters and
low perforation friction;

· Design B with low clusters and
high perforation friction;
· Design C with high clusters and
low perforation friction; and
· Design D with high clusters and
high perforation friction.
High-clusters designs C and D had
1.9 times more clusters than low-clusters
designs A and B. Likewise, stages B and
D were designed with four times more
perforation friction than stages A and C.
Additional diagnostics were run on the
3H and 7H to evaluate these design parameters. To validate actual perforation
friction, downhole cameras were used to
image the 3H and 7H perforations. In
addition, pre- and post-frac step-downs
were performed on every stage of the 3H
and 7H wells. To evaluate production
performance, a fiber optic log was run in
the 3H and 7H.
The combined dataset attempts to answer key questions, such as:
· Which design provides the highest
normalized production (bbl/ft)?
· Which design gives the most equal
treatment between clusters, and does that
matter for production?
· Do the SWPM results correlate
with the measured perforation erosion
and production log data?
Because of operational constraints,
SWPM data was only captured for designs
A, B and D while completing the 3H and
7H. Comparing the A and B low-cluster
designs, the higher perforation friction
in Design B resulted in larger VFRs than
Design A, signifying more even fluid
distribution and more uniform fractures.
Comparing the B and D high-perforation
friction designs, Design B's lower cluster
count appeared to delay VFR, indicating
more uniform fractures with fewer clusters
per stage.
Stimulation Distribution
Further exploring the theory that higher
perforation friction creates more equal
stimulation distribution between clusters
and higher VFRs, the downhole camera
data compared measured perforation area
with VFR. The distributions of stage perforation area (summation of the individual

American Oil and Gas Reporter - April 2020

Table of Contents for the Digital Edition of American Oil and Gas Reporter - April 2020