in PDF format
John McMullan, Marathon Oil Company. “Material Balance: The
Forgotten Reservoir Engineering Tool”
Material balance as a reservoir engineering tool has lost popularity
in recent years with the widening use of reservoir simulation. Reservoir
simulation is based upon the fundamental assumption of material balance,
however. Is there a place for traditional material balance analysis
in the reservoir engineering “tool kit”, or is it, as
some have suggested, a “needless distraction” to the modern
Without question, material balance provides a much simpler tool for
reservoir analysis than reservoir simulation. The data that must be
collected for a material balance study is a subset of the data required
for a simulation study. While material balance analysis is not always
successful, it often is able to quantify the original volume of hydrocarbons
in place and the drive mechanisms active in the reservoir. This understanding
of the reservoir is critical in identifying un-drained hydrocarbon
potential, well locations, and optimal completion and production strategies.
With modern computer software, material balance analysis often requires
only minutes. The vast majority of the time required is in the collection
of the data…..this same data must also be collected for a reservoir
simulation study. As such, material balance analysis should be considered
a precursor to reservoir simulation, not a replacement. Material balance
is quick, often straightforward, and can provide a valuable understanding
of the reservoir. This understanding of the reservoir has the potential
to accelerate the history matching phase in a reservoir simulation
study. There is no logical reason not to consider material balance
for reservoir analysis. This talk reviews the development and application
of material balance, and uses several examples to illustrate its usefulness
to the reservoir engineer.
in PDF format
Bill McCain, Texas A&M University. “Rapid ‘Tuning’
of Equations of State in Compositional Simulation”
A graduate school project over the last several years at Texas A.
& M. University has worked to take some of the mystery out of
‘tuning’ equations of state for use in compositional
simulation. A strategy has been proposed which appears to automatically
work for any gas-condensate or near-critical/volatile oil. This
strategy performs the tuning by altering the least accurately known
properties of the fluid. The best technique for extending the lab
measured composition of the plus fraction was determined. The best
available correlations for assigning properties to the components
of the extended composition were selected based on experimental
major outcome of this work is an understanding that the method of
the grouping the compositions of the multiple carbon number groups
from the extended composition is dependent on the composition of
the measured plus fraction of the original reservoir fluid. This
presentation will provide a correlation for doing this grouping
based on data from their study using 32 reservoir fluid studies.
in PDF format
White, Louisiana State University. “Emerging Uses of Reservoir
Simulation: Insights, Planning, and Control”
The future of simulation will provide information never before available,
but will also require more discipline, forethought and limitations.
This presentation will discuss how new methods and hardware allow
us to do sensitivity and history matching (insights), optimization
and scenario modeling (planning), and eventually guide day-to-day
decision making and operations (control). The presentation will focus
not so much on theory, but rather on applications and operations.
in PowerPoint format
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Marathon Oil Company. “Variations in Modeling with PVT Correlations
and Effects on Reservoir Performance Estimates”
At PTTC/Core Lab symposium of 2004, Dave Bergman presented a discussion
of oil viscosity correlations, their accuracy and pitfalls if an unsuitable
method is selected to represent a given crude oil. Ideally PVT properties
are known; however, in situations where PVT is an unknown, correlations
are utilized. The talk for 2005 has been expanded to discuss PVT methods
for the calculation of the major oil properties of interest for engineers.
In particular, these properties include bubble-point pressure, oil
formation volume factor, isothermal compressibility, and viscosity.
A number of correlations have been published over the years for these
key properties and the range of answers derived from these methods
can be quite variable. A conceptual black oil reservoir model was
created to test these methods and access the impact of this variability
on original oil in place, reservoir performance, oil recovery and
project life. Oil properties over the range of 20-40 API and gas-oil
ratios of 250-750 scf/STB at a reservoir temperature range of 125-250
°F were evaluated. The
talk provides an overview of oil PVT correlations and their variability.
Results from the simulation studies will be presented to quantify
the impact of correlation selection on reservoir performance and recovery.
For more information
regarding the technical program, please contact Toddy Guidry with Pencor/Core
Laboratories at 337-839-9060 ( email: firstname.lastname@example.org
Dr. John McMullen
received his B.S., M.S., and Ph.D. degrees in Petroleum Engineering from
Louisiana State University. He has worked in a variety of locations for
both independent and major oil companies. John has experience in many
domestic and international producing areas, and taught reservoir engineering
and reservoir simulation for several years at the L.S.U. Craft and Hawkins
Department of Petroleum Engineering. He currently serves as a Senior Technical
Consultant in the area of reservoir engineering for Marathon Oil Company
in Houston. John is an active member of the Society of Petroleum Engineers
and is a registered petroleum engineer in the states of Louisiana and
D. (Bill) McCain, Jr. has been a Visiting Professor in the Harold
Vance Department of Petroleum Engineering at Texas A&M University
since 1991. McCain started his engineering career with Esso (now Exxon)
Research Laboratories in 1956, where he assisted in research on surface
processing of petroleum fluids. He was Professor and Head of the Petroleum
Engineering Department at Mississippi State University from 1965 to 1976
and taught at Texas A&M University from 1984 through 1987. McCain
was a consulting petroleum engineer with Cawley, Gillespie & Associates
from 1987 until 1991. He was with S. A. Holditch & Associates from
1991 until 2000, retiring as Executive Vice President and Chief Engineer.
He currently has his own consulting firm, McCain Engineering. He wrote
two editions of the widely-used textbook, The Properties of Petroleum
Fluids, holds U.S. Patents, and has numerous publications in the field
of petroleum engineering. He holds a B.S. degree from Mississippi State
University, and M.S. and Ph.D. degrees from the Georgia Institute of Technology,
all in Chemical Engineering.
White, Associate Professor at Louisiana State University in the
Craft & Hawkins Department of Petroleum Engineering, specializes in
reservoir characterization topics including geostatistics, stratigraphy,
petrophysics and integrated modeling. Before joining the faculty at LSU,
Dr. White worked as a research scientist at the University of Texas at
Austin and with Shell Development Company. Dr. White earned both his M.S.
and Ph.D. from Stanford University in the field of Petroleum Engineering.
graduated from Marietta College in May 1978. Following graduation, he
was employed by Marathon Oil Company as a Production Engineer in the Lafayette
Gulf Offshore District office. While working for Marathon in Lafayette,
Rob took courses at the University of Southwestern Louisiana which led
to an M.S. degree in Petroleum Engineering in December 1983. While in
Lafayette, Rob had assignments in the Operations, Reservoir, and Production
Coordination Departments. In June 1985, he transferred to Marathon’s
Denver Research Center to work in the Reservoir Management Department
where he was active in reser¬voir modeling, multiphase flow in pipe
calculations, well performance analysis and training. He has worked temporary
assignments in London and Aberdeen on Marathon’s North Sea assets.
Rob wrote and maintains Marathon’s in-house multiphase flow computer
program as well as programs to evaluate PVT properties, erosional velocity,
well skin factor and gas well unloading velocity. Rob
has authored SPE papers on multiphase flow calculations, oil PVT correlations,
well performance analysis, and an improved method to calculate the com¬pressibility
factors of gas-condensates. He recently wrote the chapter on oil PVT correlations
for the SPE Petroleum Engineering Handbook.