Reservoir simulation study using CMG STARS

Sigve Hamilton Aspelund
Reservoir simulation study

Summary
1) CMG STARS:
• H2S souring
• Injectivity & fracture modelling
• Thermal or chemical processes
• IOR/EOR
• Polymer flooding/ chemical placement
• Heavy oils and light oil
2) CMG GEM:
• CO2 EOR
• Compositional features
• Fracture modelling and injectivity
• Gas processes
• CBM
3) CMG IMEX:
• Blackoil simulator
• Injectivity & Fracture modelling

Injectivity model in excel
Onsite and laboratory flooding
Fracture lengths, using the Perkins and Gonzales 2-D fracture propagation model
Injectivity, with and without thermal fracturing

Examples of reservoir simulation programmes
CMG (WinProp & Builder) Tempest More
tNavigator Tecplot

What we want for future: Reservoir simulation software
Commercial reservoir simulation software:
CMG Suite Computer Modelling Group
IMEX: Black oil simulator
GEM: Compositional simulator
STARS: Thermal compositional simulator

STARS - Advanced Processes & Thermal Reservoir
Simulator
STARS is the undisputed industry standard in thermal reservoir simulation and
advanced recovery processes. Reservoir engineers use STARS to simulate
changes to the reservoir based upon fluid behaviour, steam or air injection,
electrical heating or chemical flooding.
Chemical Enhanced Oil Recovery (EOR) - STARS simulates the wellbore
treatment procedures required to evaluate the effectiveness of chemical additives
used in chemical EOR processes. Globally, STARS is also the most widely used
foam simulator as it is the only commercial simulator to mechanistically model the
complex physical processes involved in foam flooding.

STARS Uses
 Chemical EOR
 Emulsions, Gels, Foams
 ASP. SP, ASG
 MEOR / Reservoir Souring
 Low salinity
 BrightWater®
 Thermal EOR
 Hot water
 Steam flood & cycling
 SAGD & ES-SAGD
 Combustion (LTO & HTO)
 ISC of Oil Shale
 Naturally Fractured Reservoirs
 Dual Porosity (DP), Dual Permeability (DK), SubDomain (SD), MINC
 Cold Heavy Oil Recovery (CHOPS)
 Natural Gas Hydrates
 Complex Thermal Wellbore Configurations
 Discretized Wells (transient, segregated flow of steam and bitumen in single tubing horizontal wells)
 FlexWells (transient, segregated flow of steam and bitumen in multiple tubing, undulating wells)
 Coupled Geomechanics
 GEOMECH

STARS: Souring modelling (3D)
Reactions:
Oxidation of sulfide with nitrate
Reduction of sulfate with acetate and precipitation of sulfide with ferrous oxide
Model sulfide production and nitrate-dependent oxidation in an upflow, packed bed
bioreactor and to transfer the resulting model to a field wide nitrate injection.

STARS: Souring modelling (3D)
Predicted H2S distribution in generic field model before and after nitrate injection

What STARS are used for:
• Microbial
• Surfactant
• Reactivity
• Pressure dependent properties
• Solves energy equations
• Material balance
• Reservoir performance forcasting
• Well location
• Downhole heating
• Cold production simulation
• Production and injection profiles
• Tracer transport
• Process steam injection
• Geochemistry
• Coal gasification simulation
• Cold heavy oil production
• Heat transfer
• Steam
• Heavy oil thermal recovery
• Well chemical tracer test
• Interwell tracer test
• ASP flooding
• STARS can be used for heavy and light oil

GEM - Compositional & Unconventional Reservoir
Simulator
GEM can model primary, secondary, and tertiary recovery processes, and
accurately model complex heterogeneous faulted structures, horizontal and
multilateral wells, and geomechanical deformation. GEM is used extensively for
modelling gas and liquids rich shales, coal bed methane (CBM & E-CBM) and
CO2 processes.
About: GEM is a general compositional reservoir simulator for modelling
processes such as gas condensates, volatile oils, gas cycling, WAG
processes, and many other multi-component reservoir scenarios. It can also
model gas injection processes such as miscible floods, and vaporizing or
condensing gas drives GEM accurately simulates structurally complex and
varying fluid combinations beyond conventional black oil simulators, as well as K-
value compositional simulators, including processes in which the effects of inter-
phase mass transfer (i.e. changing fluid phase composition) are important. GEM
will effectively model laboratory scale projects, pilot areas, elements of symmetry,
or full-scale field studies.

GEM Uses
 Secondary Recovery
 Miscible gas injection (CO2, N2, Sour Gas)
 Gas condensate production with cycling
 GOGD using in naturally fractured reservoirs
 VAPEX heavy oil recovery (isothermal and thermal)
 CBM & Shale Gas Production
 Multi-component desorption/adsorption, diffusion & coal swelling/shrinkage
 CO2 & Acid Gas Sequestration
 Oil reservoirs, Saline aquifers & Coal beds
 Geochemical reactions
 Asphaltene modelling during primary and secondary recovery
 Precipitation, Flocculation, Deposition & Plugging
 Dual Porosity (DP), Dual Permeability (DK), SubDomain (SD), MINC & SD-DK
 Hydraulically fractured wells with non-Darcy flow & Compaction
 Single Plane Fracs (Vertical & Horizontal Wells)
 Complex Fracture Networks (Shale Gas Wells)
 Thermal Option
 Coupled Surface Facilities
 GAP & FORGAS
 Coupled Geomechanics
 GEOMECH
20

IMEX: Three phase black oil simulator
IMEX is one of the world’s fastest conventional black oil reservoir simulators.
IMEX is used to obtain history-matches and forecasts of primary, secondary and
EOR or IOR processes where changing fluid composition and reservoir temperature
Are not important factors for accurate modelling of hydrocarbon recovery processes.

IMEX Uses
 Primary recovery
 Black Oil & Volatile Oil
 Dry & Wet Gas
 Gas Condensate
 Secondary recovery
 Waterflooding
 Polymer Flooding
 Dry Gas Injection
 GOGD in naturally fractured reservoirs
 WAG
 Pseudo-miscible Displacement
 Gas Storage
 Dual Porosity (DP), Dual Permeability (DK), SubDomain (SD), MINC & SD-DK
 Hydraulically fractured wells with non-Darcy flow & Compaction
 Single Plane Fracs (Vertical & Horizontal Wells)
 Complex Fracture Networks (Shale Gas Wells)
 Coupled Surface Facilities Modelling
 GAP, FORGAS, METTE & Avocet IAM
22

What IMEX is used for:
• Black oil simulator: 20
• Injectivity: 2
• Fracture modelling: 2
• History match: 2
• Forecast
• Conventional oil in carbonate NFR
• Polymer injection
• Water flooding
• Water injection
• Polymer flooding
• Dry gas injection
• Pseudo-miscible gas injection
• Production strategy by water injection
and drilling new wells
• Pressure dependent
• Shale gas
• Natural fractured formation
• Improved oil recovery simulation
• Non-miscible oil recovery process

What GEM is used for:
• Compositional features: 16
• CO2 EOR: 6
• CBM: 5 (Coal Bed Methane)
• Shale: 3
• Gas processes: 2
• EOS: 2
• Gas injection: 2
• Volatile oils: 2
• Fracture modelling
• History match
• Tight oil/ gas applications
• Geochemical functionality
• Gas depletion in NFR
• Shale gas modelling
• Change in composition of phases
• Miscible flooding
• Carbon capture & storage
• Fracturated reservoirs
• Non-isothermal systems
• Recovery processes

What GEM is used for:
• Geomechanical deformation
• Gas condensates
• Gas cycling
• Non-thermal
• WAG (Water Alternating GAS)
• Gas injection processes
• Simulating laboratory core flood
• Sensitivity analysis
• Creation of field scale pattern
• Production history match
• CO2-WAG process
• Optimization
• Asphaltene deposition
• Condensate
• Complex heterogenous faulted
structures
• Light oils

Enhanced oil recovery (EOR) processes

Commersial
Aspelund Consulting Energy Offshore Development International & National can
offer the client geochemical reservoir simulation studies based on the
software CGM STARS. The software is recognized as a marked leader within
geochemical reservoir simulation. Examples of applications that Oil plus can
support the industry is:
Chemical EOR:
Reservoir souring
Microbial EOR
Low salinity water flooding
Brightwater polymer flooding
Solids transport and deposition:
Fines migration
Asphaltene preciptation, flocculation, deposition and plugging
Wax precipitation
The business case (for all studies) are £100 per hour or $155

Top comments on CMG
“The well capabilities in all of our three simulators are very similar. Differences
occur when a capability doesn’t apply to that simulator (e.g. steam injection is not
relevant for IMEX, a black-oil, isothermal simulator). Additionally the grid
capabilities are very similar. Therefore, injectivity modeling and hydraulic
fracture model can be carried out in all three simulators.
The choice of simulator to use is determined by the reservoir fluids and the
fluids injected. E.g. water or dry gas injection can be modeled in IMEX, but
GEM would be need for volatile oil or condensate reservoirs, or CO2 injection
in depleted oil or saline aquifers for sequestration. For most thermal
applications you would need to run STARS.
Production from hydraulic fractured reservoirs is usually modeled in IMEX or
GEM depending on whether or not multicomponent effects, such as adsorption,
are important.
Papers SPE 132093, SPE 122530 are a couple of references you can look at the
describe modeling of fractured shale reservoirs using CMG software. General
Manager European Region CMG”

Top comments on CMG
“
1) IMEX (Black Oil simulator used for conventional reservoirs and non-complex
fluid phase behaviour)
2) GEM (Fully Compositional Equation-of-State based simulator used for
complex fluid behaviour reservoirs- also used in shale, CBM , and tight
oil/gas applications as well as CO2 EOR or sequestration. Has some reaction
and thermal capabilities)
3) STARS (Advanced- component and K-Value based simulator used for thermal
modelling and processes requiring complex reactions).”

Top comments on CMG
“IMEX: Used it for black oil model for slightly compressible oil in a sandstone
reservoir set to simulate a production history to forecast future production and
making production strategy by water injection and drilling of new wells in leftover
oil pockets. Used it for geomodeling which will be a separate area for large
discussion.
GEM: Used it simulating laboratory core flood experiment for miscible CO2
injection / sensitivity analysis / history match, creation of field scale pattern /
production history match, Simulation of CO2 - WAG process, CO2 flood
prediction / optimization etc. / Assosiate modeled fluid phase behavior using
WINPROP prior to these work. Associate at RGIPT.”

Top comments on CMG
“IMEX is a black oil simulator and models simple oil, water, gas systems. It
derives its PVT properties from tables dependent only on pressure.
GEM is a fully compositional simulator and can model individual hydrocarbon
components. It derives its phase PVT properties from a cubic equation of
state which can be pressure, temperature and composition dependent.
SOLVE STARS package includes access to GEM or IMEX as well as STARS.
The cost for SOLVE STARS is the same as STARS. General Manager CMG.”

Top comments on CMG STARS
“We have worked with many companies such as Baker Hughes, Enerplus, Suncor,
various Universities (such as the Univ. of Calgary) and research companies (such
as Alberta Innovates Technology Futures) on souring and microbial souring.
We recently conducted a history match to an actual bacterial souring process
with H2S production data for an operator and are currently working on another
project for a Steam-Generated sour gas application here in Alberta. Reservoir
engineer CMG.”
“CMG has worked extensively in the area of H2S bacterial souring and STARS
has the capability to model it. It’s capabilities have been validated with real
field data by some companies and have been published.
He conducted a study sponsored by DOE NETL on H2S production in Bakken.
Tested a possibility of production of the H2S as a result of the fracturing into
overlaying formation (Lodgepole), which is notoriously sour. CMG worked great for
this task. Petroleum Engineer at Kansas Geological Survey.”

Statistics (Old modelling projects):
0
1
2
3
4
5
6
7
8
9
Year
1996-2012: 66 projects. Average 4,1 projects per year

Finances vs numbers of projects per year

CMG users location (Market)
STARS is commonly use for EOR.
Thermal or non thermal.
Market:
Oman, Kuwait, Abu Dhabi, Qatar, Sudan,
Canada, Northern America, North Sea
CO2 injection. Petroleum engineer Saudi
Aramco.

CO2 EOR (Alternative potential with GEM)

Conclusion
Choose options in following order:
1) Chemical EOR: 3 D CMG STARS H2S study
2) Thermal EOR study with CMG STARS
3) Secondary recovery: GEM CO2 EOR study
4) 3 D Injectivity/ fracturing modelling study in CGM software depending on
reservoir fluids
5) 2D Injectivity model based on Perkins and Gonzales SPE paper
6) 2D Souring model
Injectivity modeling and hydraulic fracture model can be carried out in all three
simulators.
The choice of simulator to use is determined by the reservoir fluids and the fluids
injected

Conclusion:
CMG:
1. Cost. The CMG packages are usually cheaper than competitors. They also
offer leasing packages that are reasonable value.
2. Customer service. Because they are quite a small company, their customer
service and technical support is quite good.
3. Usability. The pre and post-processors are easy to use and easy to learn.
We find junior engineers much prefer to use the CMG packages over anything
else.

Glossary:
ASP: Alkaline-Surfactant-Polymer
SP: Surfactant-Polymer
ASG: Alkali-Surfactant-Gas
MEOR: Microbial-Enhanced-Oil-Recovery
SAGD & ES-SAGD: Steam-Assisted-Gravity-Drainage & Expaning-Solvent SAGD
Combustion (LTO & HTO): High/ Low-Temperature-Oxidation
ISC of Oil Shale: In-Situ-Conversation Process (ICP)
MINC: Multiple interacting continua method
CBM: Coal-Bed-Methane
GOGD: Gas-Oil-Gravity-Drainage
VAPEX (Vapor extraction) heavy oil recovery
CO2 gas injection
EOR: Enhanced Oil Recovery
ECBM: Enhanced Coal Bed Methane recovery
K-Value

Strengths - Thermal
45
Thermal Processes
Combustion
(THAICAPRI)
Cyclic steam
injection
SAGD
Electrical Heating
ES-SAGD
Thermal
Continuous steam injection
Leader in EOR & Unconventional Reservoir markets

Our Strengths - Chemical
46
Chemical Processes
Foam
Injection
Low salinity
water injection
ASP
CO2 injection
with Asphaltene
Precipitation & Plugging
Gel Injection

Strengths - Unconventionals
47
Enhanced Recovery in
Unconventional Reservoirs
CO2 Huff’n’PuffCBM / ECBM
Shale
Gas/Oil
Tight Gas
Microseismic
Data Imported
to simulator

Reservoir simulation companies
Weatherford is using Eclipse for reservoir simulation
Gemini is using Merlin for reservoir simulation
Belltree:
Reservoir Simulation
We can give you accurate, informative and timely simulation results thanks to working closely with major software
developers and using cutting-edge software such as ECLIPSE, IMEX & GEM. We are also work extensively with supporting
software such as WINPROP, MBAL-PROSPER-GAP & PANSYSTEM
Avasthi consulting:
Conducting black oil, PVT/ phase behavior/ complex reservoir fluid characterization/ compositional, naturally fractured,
heavy oil and thermal reservoir simulation studies, using commonly used commercial reservoir simulators (such as
ECLIPSE, VIP, CMG, MORE, etc.)

Older reservoir modelling projects
Project Company Country Date
71 Santos Australia Sep 96
94 Sponsors UK May 98
111 AMEC Azerbaijan Jun 99
172 Sponsors UK Sep 03
192 Lasmo Libya Des 99
199 Anadarko Algeria Feb 00
208 Ranger oil UK Oct 00
212 Bitech Russia Nov 00
250 ChevronTexaco UK May 02
255 Ranger oil UK Mar 02
304 Badr petroleum Egypt Mar 02
305 Shell Malaysia Jan 02
317 Chevron Kuwait Jan 02

349 Chevron Angola Oct 02
368 Chevron Thailand Oct 02
369 ExxonMobil USA Des 03
377 Schlumberger Netherlands Des 02
393 KFUMP Saudi Arabia Nov 03
397 Chevron Angola Apr 03
400 Occidental Qatar Des 04
402 Chevron Nigeria Jun 03
410 Schlumberger Russia Jun 04
416 Saudi Aramco Saudi Arabia Jul 03
418 Parsons group Oman Jul 04
431 Sponsors UK Jan 06
431 Petrobraz Brazil May 05

443 Schlumberger Australia Jul 04
487 Chevron USA Jan 05
500 CNR UK Apr 03
509 Chevron Canada Jul 05
530 Chevron Brazil Jun 06
536 Chevron UK Aug 05
549 Exxon Mobil Equatorial
Guinea
Jul 05
561 Chevron USA Nov 05
562 Chevron Angola Oct 05
563 Chevron Angola Nov 05
564 Chevron Angola Sep 06
580 PDO Oman Feb 06
600 Sponsors UK Nov 08

611 Paladin Norway Jan 06
614 CNLOPB Canada Apr 06
621 Chevron Nigeria Aug 06
636 Tullow oil UK Jan 07
638 Chevron Angola Sept 06
687 ADCO Abu Dhabi Aug 08
715 HMDC Canada May 08
715 HMDC Canada Sep 07
763 Vermilion France Jan 08
796 ExxonMobil USA Aug 08
811 Premier Vietnam Jun 08
811 Premier Vietnam Feb 09
830 ExxonMobil West Africa Jan 09

847 Nexen UK Jul 09
848 PVEP Algeria Jun 10
885 Farfield energy UK Des 09
890 ENI Angola Jul 10
890 ENI Angola Des 09
890 ENI Angola Mar 10
970 Core Labs Malaysia Okt 10
918 Farfield energy UK May 10
923 Star energy UK Jul 10
931 PDO Oman Des 11
931 PDO Oman Feb 11
936 PDO Oman Okt 11
937 Farfield energy UK Jul 10

959 Star energy Ireland Apr 11
996 Amerada Hess UK Sep 12

CMG STARS users
Title Company Country
Research Associate Heriot-Watt University UK
Operations Support Engineer Expro UK
Reservoir engineer Independent consultant Canada
Reservoir Engineer Husky Energy Canada
Research Scientist The Dow Chemical Company USA
Reservoir Simulation Engineer CMG Canada
Reservoir Engineer Husky Energy Canada
Reservoir Engineer Alberta Energy Regulator Canada
Directional Drilling Field
Engineer
Halliburton USA
Principal EOR Advisor Osum Oil Sands Corp Canada
Reservoir Engineer ExxonMobil USA
Innovation Engineer-Reservoir Husky Energy Canada
Production Technologist Shell USA

CMG STARS users
Senior reservoir Engineer Wintershall Germany
Reservoir Engineer Oxy USA
Petroleum Engineer University of Alberta Canada
Chief Scientist IOR/EOR Eni Italy
Manager CMG Venezuela
Wireline Field Engineer Schlumberger Colombia
Reservoir Engineer Petrobras Brazil
Graduate Student Penn State University USA
Research Director International research
institute of Stavanger
Norway
GeoScience/Res Eng analyst Suncor Energy Canada
Reservoir Simulation and EOR
professional
Nexen Canada
Vice President-Consulting CMG Canada
Senior Reservoir Specialist Statoil Canada

CMG STARS users
Senior Reservoir Engineer ConocoPhillips USA
Reservoir Engineer PDVSA Venezuela
Reservoir Engineer Schlumberger Australia
Reservoir Engineer BP Canada
Senior Reservoir Engineer Encana Canada
Reservoir Specialist Weatherford Canada
Reservoir Engineer BP Alaska
Reservoir Engineer Schlumberger Venezuela
Reservoir Engineer Nexen Canada
Reservoir Engineer Occidental USA
Reservoir Engineer ConocoPhillips Canada
Operation Assistant WellCem Saudi Arabia
Reservoir Engineer Shell India

CMG STARS users
Senior Reservoir Engineer Halliburton Algeria
Petroleum Engineer Kansas Geological Survey USA
Principal Reservoir Engineer BG Group UK
Senior Geotechnical IT Analyst Chevron UK
Senior Reservoir Engineer NewAge UK
Senior Reservoir Engineer Senergy UK
Senior Reservoir Engineer Oxy USA
Senior reservoir engineer Alliance Oil Company Russia
Senior Reservoir Engineer Oxy Canada
Reservoir Engineer Cairn India
Principal Petrophysicist AGR Petroleum Norway
Completions Engineer Suncor Canada

CMG STARS users
Senior Reservoir Engineer Brion Energy Canada
Senior Reservoir Engineer Suncor Canada
Senior Reservoir Engineer Statoil Norway
Sr. Reservoir Engineer Encana Canada
Senior Reservoir Engineer Alliance Oil Russia
Manager, Reservoir Engineering Nexen Canada
Reservoir engineer Repsol Spain
Senior Reservoir Engineer OMV-Petrom USA
Decision Analyst Chevron USA
Reservoir Research Engineer Total USA
PROACT Engineer Schlumberger USA
Sr Reservoir Engineer Gazprom Venezuela

Comments on geochemical reservoir simulation:
Compositional features is GEM. Reservoir engineer Hess.
CMG used to be dominant but Eclipse is getting better. Reservoir engineer
RWEdea.
Eclipse300 is good but the cost of the license is high. GEM is very good and
perhaps better than Eclipse300. GEM is reasonably priced and it is
recommended. Engineering Software Development J. Tingas Petroleum
Engineering
Regarding thermal simulator, STARS have better reputation than the others. (From
online discussion)

Professor use CMG software for EOR. STARS is good for chemical processes
and GEM is good for gas processes. Director, CIPR, Uni Research and
professor University of Bergen
CMG can simulate low salinity water flooding better as compare to Eclipse (for
field application). Operations Support Engineer at Expro.
Petroleum engineer used STARS for simulating a thermal process
(SAGD). Petroleum Engineer at University of Regina.
STARS is the industry standard for advanced process modelling and anything
with reactions, including thermal applications and complex mechanisms such
as souring, low salinity geochemical reactions, ASP, and even microbial.
Reservoir engineer used STARS to model surfactant, polymers and emulsion
injections. He has modelled souring with REVEAL simulator. Reservoir
Engineer at Petrobras

IRIS have done a lot of various simulations in STARS. Thermal, CO2 flooding in
fractured reservoir including reactivity, lowsal, chemical placement, pressure
dependent reservoir properties. Fairly reliable and rich in features. Research
Director at International research institute of Stavanger.
If you are looking to simulate black oil or injectivity/ fracture modelling in CMG's
suite of software he think you will be using IMEX. STARS solves the energy
equations in addition to the material balance. Reservoir engineer ConocoPhillips
The newer edition of IMEX has nice fracture modelling capabilities. Operation
manager at Geogreen.

Reservoir engineer have worked with CMG STARS for reservoir performance
forcasting, well location, water flooding, polymer flooding, downhole
heating (by an electric resistant cable).
CMG STARS is the right choice, over ECLIPSE (Screening at Petrocedeño)
ECLIPSE is highly recommended to model block to block communication and
migration, also the well modelling because its finite element framework and
neural networks.
CMG STARS is better accurate to model EOR and IOR process because its
equation solving engine is better suited to model easily thermal and
chemical scenarios. Reservoir engineer PDVSA Petrocedeño.

Operation assistant have been working with CMG software in cold production
simulation and Thermal Recovery simulation for heavy and extra heavy oil
reservoirs using IMEX / STARS.
- Simulation of thermal recovery process such a SAGD, HASD (Horisontal
Assisted Steam Drive), CSS (Cyclic Steam Stimulation).
- History matching of production scenarios and simulation forecasting to
improved oil recovery factor.
- Reservoir management and monitoring plan to identify the risks associated to the
reservoir properties and behavior of the thermal processes.
- Optimizing the most effective parameters of each thermal recovery process.
- Generation of the production and injection profiles of the thermal wells to the
successful design of the surface facilities. Operation Assistant at WellCem.

CMG is one the most strong reservoir simulation code among the third party
reservoir simulation software companies.
CO2 foam EOR and chemical EOR applications.
The code is well equipped with physics needed for foam and chemical EOR
applications.
It has most of reaction capabilities you need to implement any geochemical
aspects.
CMG's support service is excellent. Research Scientist (O&G) at The Dow
Chemical Company.

Most of his experience is with thermal recovery (SAGD and CSS). He has also
worked with chemical Flooding using STARS.
Reservoir engineer has been working with STARS doing thermal reservoir
simulations which usually do not include geochemistry.

In STARS he worked with ion exchange, sulphate mineral scaling reactions.
He find the concept of reaction rates a realised in STARS a bit confusing.
For a full field scale risk studies we use Eclipse in combination with
MULTISCALE and some other in-house apps.
Researcher use Reveal mostly for mineral scale modelling on a near wellbore
scale. REVEAL uses more advanced and fully thermodynamic calculator and
database from PHREEQC, but not perfect for large models.
H2S souring is a big issue.

STARS is thermal compositional flow reservoir simulator.
Capability to be coupled to a external geomechanics model.
It could be use with simple porosity and warren and root model; double porosity,
double permeability; Multiple interaction continua; and vertical refinement model.
The phase equilibrium calculations are done trough K values.
The interphase for building an input file is called Builder.
It is easy to use and easily introduce you to the keywords of the input file.
It has a set of example input files that treats a whole range of phenomena in
reservoir engineering and EOR. Researcher at IMP.

Reservoir engineer used STARS to model experiments of thermal recovery,
emulsion injection and tracer transport.
The suite contains also IMEX (the black oil simulator), GEM (Compositional
simulation), Winprop (an equation of state multiphase equilibrium package).
You can input data from other software companies importing a rescue file from
Petrel.
It has tools for graphing, exporting and visualizing data.

+Very Good, +Versatile. +Easy to learn. + Excellent technical support by CMG.
+Ideal for process steam injection, chemical injection, polymer injection can
be also modeled in situ combustion.
+Results in 2D, 3D and graphics, allows comparison wells and fields.
+Geological models can be imported from other simulation software
+ I've worked version is 2012.1 and was stable.
+ Builder has new tools of geostatistical modeling
He recommend it for simplisidad, efficiency and processing speed for thermal
recovery processes. Petroleum engineer Unknown.

Senior reservoir engineer claim that STARS is easier than Eclipse for the
beginners. Senior reservoir engineer Almajid International.
Easy to learn with a very intuitive model building platform (Builder). Black oil
simulations can easily be set up in STARS or IMEX. Very good documentation
too. Compatible with Petrel and other mesh files. Postdoctoral Research
Associate Imperial College London
Reservoir engineer used CMG-STARS for modelling some of the thermal EOR
processes (Steam injection, electrical heating etc)
Reservoir engineer is using CMG STARS for thermal projects, he used CMG
STARS for chemical EOR mainly polymer. Reservoir Simulation and EOR
professional Nexen.

STARS is basically well-know as a thermal simulator (Pioneers)
He is using it mostly for thermal EOR simulations like SAGD, CSS.
The interface is not that complicated and they provide a fairly good support.
They also hold good training sessions. Reservoir Specialist at Weatherford
PhD student is using SourSimRL for reservoir souring calculation. PhD student
Penn State University.

Senior reservoir specialist has been working with CMG products: Thermal
applications (including chemical reactions), some polymer and tracer test
simulations.
CMG has very friendly GUI (Builder) and it was easy to start using it. It took
him some time to switch from STARS to ECLIPSE. Senior reservoir specialist
found ECLIPSE to be more powerful with regards to well/group/field controls,
but less intuitive than STARS.
STARS could be used for geochemistry as it is pseudo compositional (uses k
value tables, not EOS parameters) and allows for presence of solid phase.
Chemical reactions could be modelled in all phases.
CMG also has GEM simulator which has geochemical functionality. It is fully
compositional simulator, but it cannot handle steam. Senior Reservoir
Specialist at Statoil Canada.

Reservoir engineer used CMG STARS for underground coal gasification
simulation which modelled using chemical reaction. You can use reaction to
simulate different process and you can set your reaction using two reaction
parameters. Phd Thermal Reservoir Engineer at Husky Energy.
CMG STARS is a good thermal simulator (thermal process such as SAGD, insitu
combustion) as the chemical kinetics can be modelled.
Schlumberger also offered thermal simulation in terms of Eclipse thermal.

CMG STARS is a thermal reservoir simulation software.
He use CMG for simulation of Steam Assisted Gravity Drainage (SAGD) used
in the production of heavy oil from oil sands.
He also use CMG for simulation of flow in: Carbonate naturally fractured
reservoirs (NFR) which could be applicable to:
(1) Thermal reservoirs (using STARS), with SAGD
(2) Conventional oil in Carbonate NFR (using CMG IMEX)
(3) Gas depletion in naturally fractured reservoirs, NFR (using CMG GEM, the
compositional simulator)

He has also used CMG STARS for Chemical Enhanced Oil Recovery including
polymer flooding, and alkaline-surfactant flooding.
CMG STARS is only applicable where thermal effects are very important, but he is
an expert in using it together with CMG- WinProp (for component), and CMG-
CMOST (for history matching, forecasting and optimization).
He is also involved with shale gas modelling with CMG-GEM.

To model H2S in stars, one would need to model aquathermolysis in which case
you would need to put a few reactions into the simulator. They use analytical
methods to predict H2S production from aquathermolysis. Staff Reservoir
Engineer, Thermal at Husky Energy.
Used CMG STARS and GEM to simulate H2S production in Bakken. CMG is very
powerful tool. Petroleum Engineer at Kansas Geological Survey.

CMOST is a tool that can work in conjunction with the simulator.
It can be used for Sensitivity Analysis, History Matching, Optimization, and
Uncertainty Assessment studies.
Create a STARS model that will act as a base case.
You would then bring it into CMOST and specify what parameters are uncertain
or you would like to optimize.
The idea is to remove much of the manual labor that would normally be done in
a study in having to create dataset after dataset yourself, running it, analyzing,
making changes, new model, etc. Reservoir engineer CMG.

Reservoir engineer has worked with STARS and it's Geomechanical coupling.
They used STARS to study the opportunity to model Cold Heavy Oil Production
with Sand (CHOPS) in the heavy oil fields of Venezuela. Reservoir Engineer at
Schlumberger Information Solutions.
- CMG STARS is an excellent choice for thermal processes.
- If there are lots of change in composition of phases (e.g miscible flooding,
gas injection) GEM is the standard software.
- If heat transfer is dominant in the process then STARS will be the better
choice. Petroleum engineer University of Regina.

Most compositional simulators could do that kind of studies. Schlumberger E300,
CMG Stars, Roxar Tempest, and Sensor from Coats
Engineering. http://www.scribd.com/doc/18418431/Roxar-pvt-Course
Senior Reservoir Engineer Unknown
Reservoir engineer has extensively used CMG STARS for coupled reservoir
geomechanics simulation and was satisfied by the result and speed. Reservoir
Engineer, Geomechanics Specialist, and Numerical Modeling Expert Exxon Mobil.
Most of his experience with STARS is the thermal and/or solvent processes,
without any geochemical reactions. If the process you are researching is non-
thermal, you might try CMG-GEM (compositional model). Reservoir Engineer
Nexen.

ECLIPSE has a generic mechanism of chemical reactions implemented and
water and hydrocarbon components. That allows you to simulate e.g. H2S
creation due to microbial activity. There are also specific options targeting H2S
solubility in water.
It is possible to simulate H2S production once you have lab test and have an
idea which is your H2S source (rock or oil). Then, it is possible to represent the
H2S production in the simulation including chemical reactions that represents
H2S generation (chemicals reactions coming from the lab test). It is highly
recommended use your lab or field data to calibrate your chemical
reactions. Reservoir Simulation Engineer Computer Modelling Group.

STARS: For modelling complex processes, and he would include geochemical
processes in that, it has a better reputation than Eclipse 500 and the other
commercial simulators.
CMG have a support office in Wallingford in South Oxfordshire.
His most recent experience with CMG software was with one of STARS sister-
products, GEM, which has a Carbon Capture & Storage add-on. STARS is
more reliable. Eclipse 500 is the thermal extension of E300 - it isn't anywhere
near as good as STARS! Reservoir engineer HoBoil

If you have to deal with steam you probably want to use STARS.
Reservoir engineer also used STARS with chemical reactions for in-situ
combustion.
STARS uses k-value table for the phase change properties which is not always
convenient. If you don't have to deal with steam, he suggest checking out CMG
GEM before you purchase STARS. It uses EOS for phase behavior which may
be more convenient.

Student has been working with CMG: If it's not important the composition
change as well as the temperature change in your model you might use IMEX.
CMG GEM has features in naturally and hydraulically fractured reservoirs
because it's usually used in shale reservoirs, in which the fracturing is the main
way to produce oil and gas.
STARS has both, thermal and chemical applications, it's commonly used with
compositional models.
STARS allows you to work with a black oil PVT. Student at Univesidad de
América.
CMG has more intuitive design hence, it makes easier enter the information.

IMEX is a fully featured three-phase, four component black oil reservoir
simulator for modelling primary depletion and secondary recovery processes in
conventional oil and gas reservoirs.
IMEX also models pseudo-miscible and polymer injection in conventional oil
reservoirs, and primary depletion of gas condensate reservoirs, as well as
the behavior of naturally or hydraulically fractured reservoirs. For your case of
study IMEX, it will give better forecasts. PhD, Petroleum Engineering.

We have used STARS before for CO2 storage process when we were mainly
concerned by its geomechanic all modeling features ...as we wanted to analyze
how the CO2 injection pressure will behave compared to the cap rock frac
pressure. Senior Reservoir Engineer at Statoil.
Reservoir engineer used CMG-STARS for modeling some of the thermal EOR
processes (Steam injection, electrical heating etc). Reservoir Engineer at BP.

STARS works very well. President has very good experience with all of the
CMG products. IMEX is black oil simulator and GEM is compositional
simulator. STARS is the thermal simulator. He has found them fast and very
robust.
There are different features available in Eclipse and has also used Eclipse
extensively, also with good results. President, Applied Reservoir Enterprises.
Eclipse is a wonderful simulator. The black oil simulation is very excellent. The
Local Grid Refinement (LGRs) can decribe the natural/ hydraulical fractures with
elaborate grids, which is very important to simulate the near wellbore flow.
Experienced Reservoir Engineer, looking for a new opportunity.

Reservoir engineer have used both CMG's software and Schlumberger's Eclipse
package.
The CMG software is much more intuitive to use.
Some of the features CMG are:
- the ease of transition from one simulator to another e.g. history match
primary/secondary production in IMEX and then convert to STARS for EOR
feasibility.
- extracting sub-models (this is useful when you want to test/examine a small area
of a large model and allows you many short runs the results of which can then be
applied to the main model)
- pre- and post- processing software (BUILDER and RESULTS) have high
functionality and are easy to use (much easier than PETREL or Eclipse Office).

ECLIPSE has a few features which are not available in IMEX/STARS. Two
examples are the grid coarsening option and the WCONHIST keyword.
Overall, he prefer the CMG suite.
CMG responds to problems faster. Consulting Reservoir Engineer.

Input:
A static geological model with petrophysical properties (porosity,
permeability, saturations)
Relative Permeability tables to represent the rock-fluid interactions.
Fluid Model (can be either black-oil, K-Value based, or an Equation of State
depending on what process is being modelled and which simulator is being used)
Well data (locations, operating constraints, perforation intervals and trajectories,
tubing tables- if applicable)
Dynamic information (date ranges, outputs for results- this is customizable,
numerical settings that control convergence of the simulator)

In terms of outputs it is really up to you in what needs to be examined.
You can output both results for the grid as well as for the wells.
Well data is typically examined graphically (via Results Graph) whereas the grid
properties (for example looking at how pressure changes in every gridblock with
time) is generally looked at in 3D views via Results 3D.
The list of output will be solely based on the situation and what the objective of
the simulation is.

GEM is the next step down in terms of 'complexity' and offers a compositional
modelling package with an additional thermal model for non-isothermal
systems. We have used this in the past to study volatile oil systems and gas
vaporisation.
IMEX is a conventional three phase 'black oil' simulator.
There are some benefits to using this software over all of the other packages:
1. Cost. The CMG packages are usually cheaper than competitors. They also
offer leasing packages that are reasonable value.
2. Customer service. Because they are quite a small company, their customer
service and technical support is quite good.
3. Usability. The pre and post-processors are easy to use and easy to learn. We
find our junior engineers much prefer to use the CMG packages over anything
else. Reservoir Engineer Belltree

Equations for Black Oil Model are exclusively written in IMEX (IM-Implicit EX-
Explicit) simulator.
This simulator could also be used for geomodeling purpose involving
geostatistics.
The black oil model is the simplest multi-component model which allows for mass
transfer between the phases. The black oil model is based on the following
assumptions:
1. The oil phase is considered to consist of two (lumped) components;
a non-volatile oil component (black oil or stock tank oil) and
a volatile gas component, (gas or solution gas).
2. The gas phase is considered to consist of only gas component
3. The water phase, w, is considered to consist only of water component.

STARS is exclusively written for thermal and steam injection and could be used
for Thermal EOR (such as insitu combustion, cyclic gas injection, SAGD etc.)
GEM is an Equation of State (EOS) multi-compositional simulator which is
used for miscible or immiscible gas or solvent injection for Enhanced Oil
Recovery process.
Thermodynamics of reservoir fluid and fluid flow is taken care of in this simulator.
Fluid phase behavior (with and without injected gas / solvent) through PVT
experiments should be modeled (through EOS/ optimaztion algorithm) accurately
using thermodynamic modeling software (such as WINPROP, PVTflex, PVTSIM)
before proceeding to GEM.

IMEX is the simple module of CMG which is used to build a black oil model.
There is not much work with IMEX compared to STARS and GEM since there is
no heat transfer and there in no compositional calculation. Just three phases; oil,
water, and gas.
Working with GEM requires building a good pvt model with WINPROP which
basically requires more pvt input data. Also it takes time to history match a case in
GEM. If there is composition change between phase significantly you have to
build your model in GEM. Petroleum Engineer University of Regina.
Head Angsi experience with IMEX is good but the well controls to open or shut in
wells with high GOR or Wcut are not very good in comparison with Eclipse, last
time that he used IMEX and STARS was 2007, maybe CMG has fixed this bugs.
STARS is good with heavy oil and also for EOR injecting ASP. In Petronas the
EOR simulation model was set up with STARS. Head Angsi - Resource Integrity
PETRONAS

CMG has 3 different engine, Stars, GEM, and IMEX. STARS is for Thermal
modeling like SAGD, CSS, In situ combustion while GEM use for compositional
reservoirs such as gas condensate reservoirs. IMEX is for black oil or dry gas
reservoirs.
Senior reservoir engineer has used all of them and currently using GEM for their
liquid rich shale play, Duvernay. CMG is easy to work with and very user friendly
comparing with ECLIPSE. Although ECLIPSE and PETREL RE has very strong
visulization. Senior Reservoir Engineer (Ph.D, P.Eng) at Encana

IMEX is a black oil simulator (similar to E100) and GEM is a fully
compositional one (similar to E300). However, GEM cannot handle steam.
So for the processes that involve steam STARS is the best. Senior Reservoir
Specialist at Statoil Canada.
STARS , GEM and IMEX doing reservoir simulation. STARS is thermal simulator
while GEM is compositional simulator and IMEX is black oil. Based on your
reservoir and type of process you are applying you can use the appropriate
software. Also you cannot use GEM and IMEX instead of STARS if you are
modelling a thermal process. There are some process which you can use two of
those software but its depend on mechanism of the process. Thermal Reservoir
Engineer at Husky Energy.

CMG is being developed for variety of reservoir simulation purposes.
IMEX is used when you are simulating black oil model where there is no change
in fluid composition or in some other situations.
GEM is the compositional module that is applied when there is change in fluid
composition such as CO2 flooding, asphaltene deposition, for condensate or
volatile reservoirs.
STARS was particularly developed for thermal process that heat in form of hot
water, steam etc is injected into reservoir in scenarios like STEAM FLOODING,
SAGD OR CSS. Student at the University of Calgary.

IMEX – CMG’s Black oil Reservoir Simulation (Schlumberger E100) is world
famous and reliable software.
GEM – Compositional reservoir Simulation (Schlumberger - E300) but GEM is
better than E300.
STARS – Its CMG’s Thermal Simulation pack best in class worldwide.
So if you have volatile oil and you want to run compositional simulation with
thermal recovery option then go for CMG.
If your reservoir is black oil then go for Schlumberger E100 software only.
Reservoir Engineer, Consultant.

IMEX is a black oil simulator with only gas-oil-water as components.
Here Benefits
1.- Achieve simulation results faster than any other conventional black oil
simulator
2.- Ability to quickly screen a variety of recovery mechanisms before moving
forward to more complex simulation
3.- Accurate modelling of the matrix-fracture transfer in fractured reservoirs
4.- Use the speed of IMEX to simulate shale gas modelling
5.- Fast and easy transition to enhanced oil recovery (EOR) process modelling in
GEM and STARS

GEM is a compositional simulator
Here Benefits
1.-Understand fluid property composition and behaviour
2.-Simulate recoverable reserves through advanced simulation
3.-Simulate complex reservoirs to identify optimal recovery processes
4.-Increase estimated NPV through accurate phase behaviour models
5.-Optimize field and surface operating conditions and overall recovery
6.-Seamless integration with CMOST for rapid, accurate history matches and
uncertainty analysis, while leveraging limited engineering time. Reservoir
Simulation - EOR, Researcher

IMEX is a black oil simulator with only gas-oil-water as components.
STARS and GEM are compositional simulators, so can have many
components.
STARS also has the (optional) energy equation. As a result, IMEX tends to run
much faster than STARS or GEM.
It is relatively simple to convert an IMEX dataset to STARS, so primary/secondary
production can be run in IMEX, EOR in STARS.

Note that IMEX has options which extend it's range of applicability, e.g. polymer
option, pseudo-miscible option.
The choice between STARS and GEM is more complex. In general, GEM's
equation of state formulation is better suited for lighter oils, condensate etc,
while STARS' K-value formulation is good for heavy oils. The K-value formulation
runs faster than equation of state which requires numerous flash calculations.
The suite of all three simulators allows you to handle pretty much every situation.
Consulting Reservoir Engineer. Consulting Reservoir Engineer.

CMG reservoir simulation package is famous for its user friendly Builder
interface. It is very simple to use and learn in comparison with other commercial
software. Builder literally directs user through the modelling systematically without
getting confused and miss something in your model .
CMG offers three types of simulators i.e. STARS, IMEX and GEM, each of them
has its own distinctive features.
STARS has been designed for thermal simulation and vastly used in Canada for
steam flooding in heavy oil recovery.
CMG designed a very distinctive model known as MINC model which has
primarily developed to account more correctly for connective heat flow from
fracture to matrix in thermal simulation. Once a model is built in BUILDER
interface, can be run by either IMEX (Black oil simulator) or GEM
(compositional simulator) depends on the reservoir fluid characteristic. The
difference is in PVT modelling and if you choose GEM, WINPROP is assisted to
model compositional PVT (similar to PVTi in Eclipse).

Recommend CMG software if simple interface and fast design of model is what
you are looking for. He use Schlumberger's software i.e. PETREL and ECLIPSE
which allow him to perform more sophisticated models both in RE and geological
aspects.
CMG also is pioneer in unconventional shale gas modelling by allowing user to
build very quick hydraulic fracture or SRV via its automated gridding feature
(Logarithmically Spaced LGR) which is very convenient. Student at University of
Portsmouth.

As real reservoir fluids consist of hundreds of chemical components. However, to
limit the size of the computational system, components with similar chemical
properties may be grouped into a pseudo component, treated as a single unity.
With a black-oil fluid characterization model, the reservoir fluids other than water
are assumed to consist of only two (pseudo) components, an oil component and a
gas component.
With a compositional fluid characterization model, the number
of (pseudo) components is in principle arbitrary.
So, black oil simulator does the calculations quite easily as the fluid system is less
complex than compositional fluid characterization model.
However, if reservoir fluid composition varies significantly in the reservoir or
injected fluid is different from the fluid already present in the reservoir, reliable
simulation results can be only obtained with only a compositional model simulator.

CMG-IMEX is a black oil simulator. It doesn't consider changes in the chemical
composition of hydrocarbons as the field is produced.
CMG-GEM is a Compositional Model Simulator.
Systems Engineer has used CMG- IMEX for two Oilfield development projects.
This tool is really very handy, good user interface and it gives good estimated
results.
He has used CMG-GEM for CBM field development planning where it worked
pretty well and simulated results closely matched with actual field performance.
There are many other simulators available in market like Eclipse, Petrel,
OpendTect,Tempes, MatBal, Mbal. Artificial Lift Systems Engineer, Weatherford

Reservoir and production engineer only has experience in the use of IMEX. IMEX
is a black oil simulator, you can also simulate gas reservoirs.
STARS is useful to simulate process like chemical flooding, steam flooding,
there you can manage a material balance for different components.
GEM is the compositional (volatile oil & gas and condensate reservoirs) &
unconventional. The interface with CMG is very friendly. That is one good point
that he found from CMG+IMEX instead of Petrel/Eclipse. The results are
excellent, and is one of the most used reservoirs simulators worldwide. EOR Field
Reservoir & Production engineer, Pluspetrol.

The choice of software depends on your application.
The reason the field engineer used STARS was for advanced heavy oil thermal
recovery simulation. Due to the coupled flexwell geo-mechanics it was easy to
simulate near well bore changes due to stem assisted recovery.
IMEX is more of a shale gas and naturally fractured formation simulator. Due
to its compositional nature it is great tool for improved oil recovery simulator.
GEM is a good CBM recovery tool and used for mostly gas injection based
simulation and modelling.
CMG software are all simulation tools. You would need a good geological
modelling software as CMG is very good at importing the models. Field engineer-
completion services Superior.

Petroleum engineer has only been researching CMG STARS because his main
topic is thermal enhanced oil process. This is used to simulate changes to the
reservoir based upon fluid behavior, steam or air injection, electrical heating or
chemical flooding.
According to your question, it's not adequate use one of these instead of other
one. It depends of the kind of process to be simulated.
IMEX is used to obtain history-matches and forecasts of primary, secondary and
enhanced or improved oil recovery processes where changing fluid composition
and reservoir temperature are not important factors for accurate modelling of
hydrocarbon recovery processes. This one could be used for non-miscible oil
recovery process like water injection.

GEM can model primary, secondary, and tertiary recovery processes, and
accurately model complex heterogeneous faulted structures, horizontal and
multilateral wells, and geomechanical deformation. GEM is used extensively for
modelling gas and liquids rich shales, coal bed methane (CBM & E-CBM) and
CO2 processes. Petroleum engineer (Former Weaterford)
All of the CMG simulators are relatively compatible (they each will have cards
specific to the application). We used IMEX for fairly simplistic models, but found
the model construction and runs to be straight forward, and the runs were
significantly faster than Eclipse or VIP, two of the major competitors. Chief
Reservoir Engineer - Permian CO2, Oxy Permian.
Reservoir engineer has used IMEX fairly extensively and it is the easiest simulator
to learn on for black oil. Reservoir Engineer, BP.

Picking between STARS, IMEX and GEM depends on the purpose.
For black oil simulation IMEX should be sufficient. The question was picking
between IMEX, Eclipse100, etc. It was just the software package that my
company used at that time. The upside of IMEX to E100 is the user friendly GUI
which is very suitable for beginner. But, when you start going in depth in IMEX the
reservoir engineer ran into problem of depending too much to GUI, and the
manual did not help that much in diving into keywords.
If you want to use compositional modelling or CBM, GEM is the way to go.
If you want to do advance stuff like thermal simulation or EOR, STARS is the
best. I don't have significant experience with those packages. However, STARS is
known in the industry as one of the best for advanced simulation. Reservoir
engineer Chevron.

Student has worked with CMG GEM and IMEX during his undergraduate and
worked with CMG GEM for a year for my undergraduate thesis on coal bed
methane recovery. Presently, in Heriot Watt he is working mainly with Eclipse 100
but the Eclipse file can easily be converted to a CMG file. MSc Petroleum
Engineering Student at Heriot-Watt University.
IMEX is a much easier simulator to use than Nexus, and more importantly,
reduces the cycle time on decision making. You can also create the geological
model and do the simulation in the same environment, vs using petrel/eclipse.
Additionally, Winprop, the fluid simulation from CMG, is easy to integrate within
the entire simulation package.
The user help manual and documentation is much more user friendly and
understandable than Nexus.
Shell uses CMG. Don't know what the other operators use. We use
Nexus. Reservoir Engineer, BP

PhD student have been working with CMG package for the last five years, three
as a graduate student, two of them as a CO2 WAG researcher. He is advanced
user of CMG GEM, CMG Winprop and CMG CMOST.
He is proficient with compositional simulation, recovery optimization, building
grids and input data, importing and exporting data, interpreting data,
modelling phase behavior and fluid properties, including transport
phenomena and three-phase hysteresis for miscible EOR and uncertainty
analysis and making production forecasts. He has fewer experience with
hystory matching and economic decision analysis, only basic knowledge of
fratured reservoir modelling, basic knowledge of integrated reservoir and
surface modelling, basic knowledge of polymer injection modelling and
thermal processes modelling on STARS.
Their group has been using CMG IMEX for the last 25 years, some of them are
proficient in developing in house applications and in house simulators as well and
are familiar with most aspects of black oil simulator conception. PhD Student,
UNICAMP.

Graduate teaching assistant has worked on these softwares quite a long time and
his current project is in CMG STARS. Injectivity option is available in CMG IMEX
under wells section, where you can give constraints for injection (such as BHP,
injection rate, etc) and alter injectivity index. Graduate Teaching Assistant,
University of Alaska Fairbanks.
If you are looking at fracture modelling you might find GEM's hydraulically
induced fracture modelling more accurate unless you have micro-seismics and
are looking at pre-existing fractures.
Injectivity calculations are partly taken into account when inputting the injection
well properties however formation damage will not be taken into account when
injection pressures and rates reach unrealistic levels, and so separate calculations
need to be made and adjustments to the skin be input for the simulation run.

If you wish to create fracturing for EOR then I'd recommend a dual porosity GEM
model, however if it is a simple black oil model then IMEX will provide faster
simulation runs, fracturing can be introduced in IMEX, but GEM is better suited to
fracture modelling. Injectivity is standard throughout the CMG software
suite. SPE student chapter President, The University of Portsmouth.

Computer Modelling Group (CMG) currently offers three simulators: a black oil
simulator, called IMEX, a compositional simulator called GEM and a thermal
compositional simulator called STARS.
If your goal is to perform a thermal simulation then CMG-STARS is a good
solution to simulate changes to the reservoir based upon fluid behavior, steam or
air injection, electrical heating, geo-mechanical processes or chemical flooding.
CMG used to be more user-friendly but, now with Petrel+Eclipse I think they are
about the same.
A third option that you may explorer is tNavigator from Rock Flow Dynamics that
supports black oil, compositional and thermal compositional
simulations. Reservoir-Production Planning Engineering Advisor Afren

Research assistant has used SourSimRL to match souring results in a large field
and several lab experiments.
SourSimRL can be coupled easily with many reservoir simulators therefore there
is no need to create a new field model for souring calculations.
The microbiological model is simple and efficient, and he was able to derive an
analytical solution for bio-reactors. They could match field H2S production
results with few matching parameters.
If he was going to mention limitations of SourSimRL, the software is slow for
field simulation (almost 10 times of the flow simulator), the input files are large
(for example 50 Gb), the input parameters are in table format which makes
matching process more difficult, and the solver had problem for some lab
experiments. Graduate Research Assistant, The Pennsylvania State University
(PdD)

Simulation engineer has been using CMG STARS for both academic and practical
projects, including numerical interpretation of single well chemical tracer test,
interwell tracer test, ASP flooding, and geomechanics study of steam
injection.
He converted an CMG STARS model to STARS-ME model, and run ASP
flooding on STARS-ME. STARS-ME is a beta version simulator developed by
CMG replacing the vapor-liquid equilibrium by a brine-oil-microemulsion (ME)
phase equilibrium, but kept all other features of CMG STARS. Simulation
Engineer, Chemor Tech.
Graduate research assistant has been using CMG GEM & STARS for 2 years. It
is very easy and elaborate to model injection wells, be it steam, water or gas
injection. Modelling hydraulic fractures is like increasing the permeability of grid
blocks representing fractures, using grid refinement to maintain numerical
stability, modelling stimulated reservoirs volume around fractures.
He use CMG GEM to model CO2 injection in a modelled oil shale reservoir.
CMG Winprop to model the reservoir fluid. Graduate Research Assistant,
University of Oklahoma.

If you want to choose between Schlumberger Eclipse and CMG, graduate
research assistant would say CMG is better. CMG has a GUI which helps a lot to
start from stratch, while in ECLIPSE, every needs to be added in the code file.
CMG also has CMOST, which is useful for history matching, sensitivity analysis.
Graduate Research Assistant, University of Oklahoma
Compared to other commercial software available, they have a full package that
does most Petroleum Engineering simulation runs one could think of. See the link
below to see some similarities: http://folk.uib.no/fciop/sim_cmg.htm
Course Administrator (Temp), University of Portsmouth
With CMG, you can achieve below fracturing and for that you need to select
DualPerm at the initial project creation. More guidance you can get over net on
CMG manual- available freely. Senior Application Analyst - Oil and Gas,
Accenture

Reservoir engineer has been using CMG software for the past 6 years. It is like
everything else has its own advantages and disadvantages both for users and
companies buying it with respect to competitors like VIP, Eclipse or tNavigator.
It has pretty simple user interface, manual is not that great compared to SLB
Eclipse, and it does not have any G&G core like Petrel, so you have to use some
external programs as well. The license is relatively cheap compared to Eclipse
though. I would say it is very strong if you need simple mechanistic sector model. It
is very easy to set up and run. Pretty accurate and has a good industry feed back
on STARS simulator ( Steam, Thermal and Advanced Reservoir Simulator). I am
not quite sure what their recent developments are, still using 2011 version, but I
really liked their idea about implementing Flexi Wellbore module that calculates
pressure drop across the wellbore on the separate grid block system. It is quite
good for horizontal and inclined well. Depending what the goals are it could be a
good tool. Reservoir Staff Engineer, Oxy

Graduate research assistant didn't have serious problem with SourSim in terms
of stability. I mean, I could usually get some results for the cases that I was
running. However sometimes, results were inconsistent, for example negative
H2S concentration. SourSim was failing more for the bioreactor models and it
was because of high flow rates and large time steps. My impression was that
the solver is not very strong and small time steps should be used. Graduate
Research Assistant, The Pennsylvania State University
Reservoir engineer has never used it for any Complex Chemical problems
besides hydrates formation in porous media. He think it is more for GEM
applications, it sounds like more compositional problem rather than thermal, but
he might be wrong cause STARS is capable of simulating Alkaline & Chemical
flooding too. He is not sure about accuracy of calculations though. It is a good
question to ask support team directly about capabilities of CMG handling this kind
of problem. Please check CMG website. They are very helpful. Reservoir
engineer Oxy.

Managers experience with H2S involved determining emergency planning zones
for proposed new wells with potential H2S hazards. Basically, he would analyze
offsetting wells from the same formation to determine absolute open flow (AOF)
and H2S content. This would be used to determine different radii for designated
risk zones and corresponding emergency response plans would be put in place for
each zone.
He has run the CMG software (IMEX, STARS and GEM) for a variety of projects:
conventional gas and oil, enhanced recovery schemes such as water flooding,
CSS and SAGD. Manager, Engineering Specialist, Deloitte Canada.
A mechanistic software names UTCHEM is research-oriented one specializing at
Chemical EOR, geochemistry reaction, microbio-EOR. I have been using it for
studying polymer injectivity. You can search UT CPGE UTCHEM for more
information if you are interested in. Ph.D. Candidate, Mewbourne School of
Petroleum and Geological Engineering at University of Oklahoma

Please find attached a couple of papers CMG staff have published on souring and
a PDF copy of a presentation. I’m also attaching a simple STARS dataset that
models a microbe growth process. It’s got some comments in their so that you can
probably understand what it’s doing. But just to give you an idea, there are various
components such as ‘Nutrients’, ‘Microbes’ defined as well as the hydrocarbon
components and water. Then a reaction is set up that defines the microbe growth.
You are free to define whatever chemical reactions you like in STARS. You just
need the stoichiometry and reaction rates. General Manager CMG.

Market: Oil production companies
The market Oil plus should approach:
Oman, Kuwait, Abu Dhabi, Qatar, Sudan, Canada, Northern America, North Sea
CO2 injection
Oman:
S.A.O.C. (OOC), PDO, Daleel Petroleum Company, Petrogas E&P, Shell
Development Oman, Occidental Mukhaizna
Kuwait:
KUFPEC, KOC, Oil Development Company, Arabian Oil Co Ltd
UAE:
ADNOC, Atlantis Holdings Norway, Crescent Petroleum, Dragon Oil, Margham
Dubai Establishment, Occidental Petroleum Corporation, ZADCO, ADCO, Abu
Dhabi National Energy Company, Dana Gas, Dubai Petroleum Establishment,
Exillon Energy, PetroChina International Iraq, RAK Petroleum, Abu Dhabi Oil,
Bahar Energy Limited Company, Bin Ham Petroling, Exxon Mobil.

Qatar:
Qatar Petroleum, Qatargas, Qatar Liquefied Gas Company, Sphere Petroleum,
Maersk.
Sudan:
Advanced Petroleum Company, White Nile Petroleum Operating Company,
Greater Nile Petroleum Operation Company Limited, Petrodar Operating Company.
Canada:
Encana corporation, Nexen inc, Talisman Energy, Apache Canada, Calvalley
Petroleum, CNR, Cygam Energy, Epsilon Energy, Oando Energy Resources,
Sagres Energy, Canadian Superior Energy, TransGlobe Energy Corporation,
Vast Exploration, Adira Energy, Africa Oil Corporation, Brownstone Energy, Bukit
Energy, Canacol Energy, Caracal Energy, Centurion Energy International, Gran
Tierra Energy, Husky Energy, Longford Energy, Madison PetroGas, Mart
Resources, Niko Resources, Perisson Petroleum Corporation, Petro Viking Energy,
Petro Vista Energy, Rally Energy, Tanganyika Oil Company, Westbridge Energy
Corporation, WesternZagros Resources, Mira Resources Corp, Serinus Energy.

USA:
Hess Corporation, Marathon Oil Corporation, Noble Energy, Pioneer Natural
Resources Company, Anadarko Petroleum Corporation, Chesapeake Energy
Corporation, Chevron Corporation, ConocoPhillips, Devon Energy Corporation,
EOG Resources, ExxonMobil, Murphy Oil Corporation, Newfield Exploration
Company, Penn Virginia Corporation, Range Resources Corporation, Shell Oil
Company, Hunt Oil Company, Kosmos Energy, Merlon International, TransAtlantic
Petroleum, VAALCO Energy, Abraxas Petroleum Corporation, Apache Corp,
AsherXino Corporation, BPZ Energy, Circle Star Energy Corp, Contango Oil &
Gas Company, Crescent Global Oil, El Paso Corporation, Endeavour International
Corporation, Thunderbird Resources Equity, Greenfields Petroleum Corporation,
Harvest Natural Resources, Heavy Earth Resources, Houston American Energy,
Hydrocarb Corporation, IPR Group of companies, New Horizon Exploration,
Pangea Energy Corp, Blacksands Pacific Energy Corporation, TransMeridian
Exploration Incorporated.
Mexico:
Pemex

Norway:
DNO International ASA, StatoilHydro, InterOil Exploration and Production, Panoro
Energy ASA.
United Kingdom:
Afren Plc, Burren Energy, Europa Oil & Gas, Genel Energy Plc, Gulfsands
Petroleum, Hardy Oil and Gas Plc, Larsen Oil and Gas, Perenco, Tullow Oil plc,
Amerisur Resources, BG Group Plc, Bowleven Plc, BP Plc, Elixir Petroleum Ltd,
Global Energy Development PLC, JKX Oil & Gas plc, Leni Gas & Oil Plc,
Max Petroleum PLC, Mediterranean Oil & Gas Plc, Melrose Resources plc,
Northern Petroleum Plc, PetroLatina Energy, Primeline Energy Holdings Inc,
Prontinal Ltd, Serica Energy Plc, White Rose Energy Ventures, Zoltav Resources,
New Age (African Global Energy), President Energy Plc, Premier oil.
Former recent clients (Potensial clients):
PCSB (Malaysia), Cairn India, BHP Billiton Petroleum (Australia), ENI (Ghana)

India:
ONGC, Oil India Limited, Gujarat State Petroleum Corporation, Indian Oil
Corporation, ONGC Videsh.
Australia:
Oilex, Woodside Petroleum, Bounty Oil & Gas, Cooper Energy, Dart Energy,
Range Resources, Sprint Energy Limited, Jupiter Energy.
Ghana:
Ghana National Petroleum Corporation.
Angola:
Sonangol, Esso Exploration and Production Angola, Total E & P Angola, Cabinda
Gulf Oil Company Limited, PetroPlus Overseas, Sonangol Natural Gas.

Russia:
Rosneft, Gazprom Neft, PetroNeft Resources, Sibirenergy Company, TNK-BP,
Urals Energy Public Company, Bashneft, Irkutsk Oil Company, LukArco Company,
Lukoil Oil Company, Naftna industrija Srbije, Naryanmarneftegaz Company,
RusPetro, Surgutneftegas, Victoria Oil & Gas, RUSIA Petroleum Company,
Udmurtneft, Novatek.
Brazil:
Barra Energia, BG Brasil, Brasoil, IBV Brasil Petroleo, Parnaíba Gás Natural,
Petrobras, Petrominerales, Queiroz Galvao, Repsol Brazil, BP Energy do Brasil,
Chevron Brasil Petroleo.
Vietnam:
PetroVietnam Exploration Production Corporation.

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