American Oil and Gas Reporter - April 2016 - 45

sand. Very low drawdown was observed
during pumping, indicating high fluid
mobility. The final buildup pressure was
close to the initial buildup pressure (a
difference of less than 0.5 psi), indicating
almost no reservoir depletion while pumping 16.6 gallons of fluid volume.
Good stabilization of the final buildup
pressure also indicated the presence of
high-permeability, continuous reservoir
strata, and not a limited fluid compartment.
A derivative plot of the buildup data also
indicated radial flow only, without any
indication of a nearby permeability barrier.
Integrating geologic, geophysical and
reservoir engineering data in the structurally complex deepwater Gulf is imperative for successful field development.
Surface seismic and borehole seismic
data are crucial in understanding the regional geology, while borehole geologic
data are essential to understanding reservoir details. For the Marmalard 2 well,
surface seismic and borehole seismic indicated that regional structural dip was
low. However, closer examination of the
geology using borehole imaging revealed
that the structural dips within the thick
shaly zones under- and overlying the
reservoir sands were highly variable.
The integrated results enabled total
understanding of the geology. After the
deposition of the shale-rich mass-transport
deposits, the overlying reservoir sands
were deposited in the field area, and this

ERIC ZIMMERMAN is vice president
of geology at LLOG Exploration. He
joined the company in 2007 as a deepwater geologist. Zimmerman has focused
his career on exploration and development projects in the deepwater Gulf of
Mexico, with previous experience at
BP and Dominion. He holds a B.S.
and an M.S. in geology from Louisiana
State University.
CARLOS GUZMAN is a geoscientist
consulting for LLOG Exploration. With
more than 40 years of industry experience, he began his career at Shell,
where he held assignments in land and
marine seismic acquisition, processing,
and interpretation. Guzman's interest
in borehole geophysics dates to the
late 1980s, when he participated in designing and interpreting walk-away
and walk-around borehole profiles in
Shell's Auger and Mars deepwater
fields. He holds an M.S. in physics
from Purdue University.

process was repeated multiple times. The
reservoir engineering analyses help confirm the extensive continuity of the sand,
which otherwise would be in question,
given the presence of mass-transport deposits both under- and overlying the reservoir sands.
❒

Instrumentation
for MWD

Editor's Note: The authors acknowledge Mike Vercher and Stan Hewitt at
LLOG Exploration, and Vinay Mishra,
Elizabeth Ruiz and Nellyana Charmelo
at Schlumberger for their contributions
to the preceding article, as well as their
assistance with the integrated subsurface
modeling work on the Son of Bluto 2
and Marmalard wells.

Coming In May
The May issue examines best
practices for managing multiphase
production streams in unconventional plays, including flow measurement, vapor recovery, inventory
monitoring, tank gauging and custody transfer. Reports also present
one independent's strategy to enhance compression across its gathering and midstream operations, and
insights on compliance requirements
for subpart W of the EPA's Greenhouse Gas Reporting Program.

ANISH KUMAR is a geology domain
champion for Schlumberger's North
American offshore wireline operations.
After beginning his career as a geologist
and laboratory manager for Special
Core Analysis Labs Inc., Kumar joined
Schlumberger in 2001 as an interpretation development geologist focusing
on borehole geology and deepwater
deposits. He holds a Ph.D. in geology
from Texas Tech University.
MICHAEL MAHNKE retired from
Schlumberger in 2016 after a 35-year
career that began as a field engineer
in the Gulf of Mexico. He subsequently
moved to New Orleans as a wireline
sales engineer, and then to Houston
and Dallas in various positions with
Geco-Prakla and WesternGeco. In
2002, Mahnke returned to Schlumberger's wireline operations in Houston
as borehole seismic sales manager,
and later served as geophysics domain
champion up to his retirement. He
holds a B.S. in electrical engineering
from the University of Wisconsin.

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APRIL 2016 45

American Oil and Gas Reporter - April 2016

Table of Contents for the Digital Edition of American Oil and Gas Reporter - April 2016