American Oil and Gas Reporter - August 2016 - 52

SpecialReport: Horizontal & Innovative Drilling
FIGURE 2A
Vertical (Left) and Horizontal (Right) Displacement in Upper Three Forks

FIGURE 2B
Horizontal (Left) and Vertical (Right) Stresses in Upper Three Forks

properties were previously obtained.
The objective of the study was to input
these parameters into the model and perform a numerical simulation using commercial software (Itasca Consulting Group
Inc.'s FLAC® 2D) to evaluate how stresses
change around the borehole, and investiMEHDI OSTADHASSAN is an assistant
professor in the department of petroleum
engineering at the University of North
Dakota. Before joining UND in 2013, he
worked as a petroleum geophysicist in
various capacities and also served as the
energy division manager for Atlantic Int.
Operation, a United Arab Emirates-based
company. Ostadhassan holds a B.S. and
an M.S. in petroleum engineering from
Iran's Petroleum University of Technology,
an M.S. in petroleum geophysics from the
IFP-School in France, and a Ph.D. in petroleum engineering from UND. His main
research areas are geomechanical modeling and nano-scale characterization of
unconventional reservoirs.
SIAVASH ZAMIRAN is a geotechnical
engineer at Marino Engineering Associates Inc., and a Ph.D. candidate in geotechnical engineering at Southern Illinois
University Carbondale. He also is the
administrator of www.zamiran.net, a website focusing on geotechnical and geomechanical topics. Zamiran has presented

52 THE AMERICAN OIL & GAS REPORTER

understand failure occurrences around
the borehole and predict possible failure
zones. Uniaxial and triaxial rock mechanics
testing on core plugs was used to derive
the unconfined compressive strength and
internal friction angle data for MohrCoulomb failure analysis.
Mechanical properties for the simulation work were obtained through a
combination of data resources. Core
plugs were tested at a geomechanics laboratory to obtain Young's modulus and
Poisson's ratio. Since the plugs were
taken from older cores at the North
Dakota Geological Survey's library, the
resulting data were compared to data
gathered at the Energy & Environment
Research Center (EERC) at the University
of North Dakota to improve the accuracy.
Pore pressure and other reservoir properties also were picked from the same
collection of data.

gate the impact of adjacent wells on
stress variations. All analysis was conducted in a vertical cross-section through
the horizontal sections of the wells using
FLAC 2D to model the wellbores.
The final step was running the model
under Mohr-Coulomb failure criterion to

Input Data
The model used input data from the
second and third benches of the Three
Forks. Vertical stress was 76 and 76.5
megapascals (MPa) for the second and
third benches, respectively, and horizontal
stress was 67 and 67.3 MPa. Young's
modulus was 25.8 and 29.3 gigapascals
(GPa) for the second and third benches,
respectively, with bulk modulus of 19.5

several workshops and short courses on
computational geotechnics.

engineering from the University of Illinois
at Urbana-Champaign.

HADI JABBARI is an assistant professor in the petroleum engineering department at the University of North
Dakota. Before joining UND in 2013,
he worked in various petroleum and
production engineering capacities. Jabbari holds a bachelor's in production
engineering from Petroleum University
of Technology in Iran, a master's in
reservoir engineering from Sharif University of Technology, and a Ph.D. in
petroleum engineering from UND.

BAILEY BUBACH is a professional
adviser and lecturer in the department
of petroleum engineering at the University
of North Dakota. She is the co-author
of several publications on geology, petrophysics and geomechanical characteristics of unconventional reservoirs, with
a focus on the Bakken and Three Forks
formations. Bubach holds a B.S. and an
M.S. in geology from the University of
North Dakota.

is an assistant
professor in the civil engineering department at the Southern Illinois University Edwardsville. His industry experience prior to joining the SIU faculty
includes serving as a geotechnical engineer at Marino Engineering Associates.
Osouli holds a B.S. and an M.S. in civil
engineering from Sharif University of
Technology, and a Ph.D. in geotechnical
ABDOLREZA OSOULI

BEN OSTER is a geologist on the geomodeling team at the Energy & Environment Research Center (EERC) at the
University of North Dakota, where he
develops geophysical subsurface models,
performs regional geophysical characterizations, and conducts petrophysical
analyses of geophysical data. He holds
A.S. and A.A. degrees from Williston
State College, and a B.S. and M.S. in
geology from UND.

American Oil and Gas Reporter - August 2016

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