American Oil and Gas Reporter - January 2019 - 63

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Unconventional Resource Science
The severe asymmetry observed in the
microseismic event patterns for the H2
well, which was not anticipated based
on the H1 MDD depletion pattern, was
accurately predicted by the hydraulic
fracture model using the geomechanical
modeling results based on the H1 history
match pressure distribution.
The consistency of the modeling results
and microseismic data support the interpretation that the MDD depletion outline
represents the region of primary depletion
associated with the propped hydraulic
fractures. Low-conductivity, unpropped
hydraulic fractures result in a region of
secondary depletion that can cause severe
asymmetry in new well hydraulic fracture
geometry at distances well beyond the
area of primary depletion. Extreme hydraulic fracture asymmetry at similar
distances has been observed in microseismic data from other projects, supporting the reliability of the hydraulic
fracturing, geomechanical and reservoir
simulation models.
Reservoir Simulation
The final step in the workflow was
incorporating the hydraulic fracture
modeling results for the infill wells into
the reservoir simulation grid and history
matching the LK DSU production. Figure
5 presents a portion of the reservoir
simulation grid, showing only the hydraulic fractures, including the locations
of the various proppant types and the
unpropped regions. As evidenced by the
microseismic data and almost continuous
frac hits, there is significant interlacing
and overlapping of fractures from all
four wells.
Frac hits on the H1 during completion
of the three infill wells resulted in a significant increase in H1's production. Although the reservoir simulation model
(which included the effects of offset well
hydraulic fractures connected to the H1
lateral or intersecting H1 fractures) predicted slightly lower oil rates, the modeled
results were in reasonable agreement with
actual production. The predicted water
cut and GOR also were in reasonable
agreement with actual data.
The history match of the initial eight

months of oil production from the three
infill wells showed good agreement between the simulation model and actual
FBHP. The water cut and a general upward
trend in GOR also were predicted adequately. Surprisingly, little adjustment
was needed to achieve the match. However,
the compaction table for the propped and
unpropped fractures was adjusted to model
a less severe reduction in conductivity
with increasing closure stress.
This resulted in an approximately
threefold increase in fracture conductivity
compared with the history match of initial
H1 production. The apparent increase in
fracture conductivity likely is related to
the significant overlap of hydraulic fractures within the LK DSU. While limited
to the first eight months of production,
CRAIG CIPOLLA is a senior engineering adviser with Hess Corporation,
providing hydraulic fracturing, completions and reservoir engineering
support to Hess' business units worldwide. His expertise in tight/unconventional reservoirs includes hydraulic
fracturing, geomechanics/geophysics,
and reservoir engineering. Prior to
joining Hess, Cipolla was chief engineering adviser for hydraulic fracture
monitoring and optimization at Schlumberger. He previously had served as
vice president of stimulation technology
for Carbo Ceramics, and as vice president of engineering for Pinnacle Technologies. Prior to that, Cipolla held
positions with Union Pacific Resources,
CER Corporation and Dresser Titan.
He is a past Society of Petroleum Engineers distinguished lecturer on hydraulic fracturing, and was the 2013
recipient of the SPE International Completion Optimization and Technology
Award. Cipolla serves on the organizing/technical committees for the Unconventional Resources Technology
Conference and SPE's Hydraulic Fracturing Technology Conference.

this preliminary history match has provided significant insights into hydraulic
fracture conductivity, effective fracture
lengths, and the connectivity between
the MB and TF.
Integrating MDD, microseismic fracture geometry measurements, geomechanical modeling, advanced hydraulic
fracture modeling and detailed reservoir
simulation provided valuable insights into
depletion patterns, MB-TF connectivity,
infill well fracture geometries, and the
effects of frac hits on parent well performance. Hess is applying the lessons
learned on the LK DSU project to develop
more reliable models that are playing a
pivotal role in optimizing completions
and well spacing in the Bakken/Three
Forks play.
r
MONET MOTIEE is a senior completions engineer with Hess Corporation,
working on the Stampede Project in the
Gulf of Mexico. Since joining the company in 2012, she has worked in a number of roles, including spending four
years in Hess' Bakken group as the
south-of-the-river completions engineer.
During her time in the Bakken, Motiee's
major projects included technical evaluation and implementation of completion
design pilots such as increased stage
counts and plug and perf completions,
and leading Bakken drilling spacing
unit and fracture modeling efforts. She
holds a B.S. in mechanical engineering
from the University of Texas at Austin.
AICHA KECHEMIR is a senior reservoir engineer with Hess Corporation,
working in the North Dakota Bakken
Shale play. She has 18 years of experience
in all aspects of oil and gas operations,
including reservoir modeling, reservoir
engineering, production, operations, depletion planning, strategic planning, economic evaluations and capital budgeting.
Before joining Hess in 2008, Kechemir
worked for nine years as a petroleum
engineer for SONATRACH.
JANUARY 2019 63

American Oil and Gas Reporter - January 2019

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