low

The first secondary production plan in Iran
commenced in 1977 in Haftkel field with the
application of gas injection. Then, in 1978 gas
injection in Gachsaran field with the target of
pressure maintenance was implemented. Gas
injection to these fields are still continuing till
now. Immiscible gas injection to Gachsaran, Bibi
Hakimeh, Aghajari, Koupal, Marun, Pazanan,
Karanj, Parsi, Haftkel and Lab Sefid and miscible
gas injection to Ramshir and Darquein are
currently being conducted. While there is no
water injection in any of the onshore fields, IOOC
conducted several water injection projects on
offshore fields due to availability of seawater.
Salman, Siri C, Siri D, Siri E and Balal fields are
those water injected fields under supervision of
IOOC. It should be noted that since these water
injections are done with the main objective of
pressure maintenance there may have been
little studies performed to determine possible
alteration of rock/fluids properties (e.g. water
salinity and composition have not been optimized
for wettability alteration).
Table 3 provides information of water and
gas volume injected to some of the onshore
fields in 2014 for IOR/EOR purposes. Offshore
implementation of EOR/IOR methods is more
cost consuming and challenging compared to
the onshore fields. Additionally, long distance
between injectors and producers in offshore fields
makes chemical EOR projects to be challenging.
Due to access of water in offshore fields, waterbased
EOR seems to be more interesting and
applicable compared to onshore fields in which
there is less access to water.
Due to low injection rate of water and gas in most
of Iranian fields (due to technical and operational
issues as well as limited access to gas in onshore
fields, especially in winter season), cumulative
injected volume will be far less than required
amount even in long periods of time. To maintain
the reservoir pressure, injected volumes of water
are severely small and usually have no EOR/IOR
impact.
Table 3: Volume of Gas and water injected to Iranian fields [8]
Oil Field
Haftkel (Gas Inj)
Rag Sefid (Gas Inj)
Marun (Gas Inj)
Gachsaran (Gas Inj)
Bibi Hakimeh (Gas Inj)
Koupal (Gas Inj)
Karanj (Gas Inj)
Ramshir (Gas Inj)
Parsi (Gas Inj)
Pazanan (Gas Inj)
Nargesi (Gas Inj)
Darquein (Gas Inj)
IOOC fields (Water Inj)
Gas (MMm 3 /Day)
0.25
0.02
15.12
15.31
3.78
2.01
5.61
0.13
2.12
5.10
0.11
6.2
295.9
Saudi Arabia has injected more than 2 MMbbl of
water per day just in Qawar field, since1964 [9] .
This pressure maintenance activities in addition
to improving composition of injected water as
the tertiary recovery method have caused the
production remaining at 4.5 MMbbl per day and
the recovery factor of 54% which have been
achieved. This in comparison with water injection
of about 259.9 MMbbl per year in all of the fields
of Iran shows that there is a need to modify the
injection plans with new mindsets based on more
detailed studies.
Although it have been planned to increase the
recovery factor by an amount of 2.5% by the
end of fifth development plan, it might not be
suitable target in comparison with other oil
producing countries. It should be also considered
that reduction in average production rate of
Iranian fields is about 9-11 % per year. With an
average recovery factor of 25% for Iranian fields
and this annual decline in production rate, Iranian
crude producers are only able to produce 134,400
MMbbl of oil without application of any EOR
technique.
To maintain the reservoirs’ pressure, it’s highly
important to initiate the water/gas injection
projects in an appropriate time to reach the
planned production targets and eliminate the
possibility of irreversible losses of recoverable
reserve potentials. It is vital to note that secondary
and tertiary recovery methods are necessary in
Iranian fields to maintain the optimum sustainable
production [7] .
Challenges of Implementing EOR
Projects in Iran
Looking into previous experiences of IOR/EOR
projects in Iran, some challenges for successful
implementation of projects can be determined:
1. Selection of the most appropriate EOR
method requires very good understanding
about the residual oil and reservoir
performance, advanced simulations, highqualified
laboratory work as well as pilot
application to verify the potential and reduce
the uncertainties. It seems to be that there
are limited available data for such studies,
and thus the decisions have sometimes been
taken based on unreliable and uncertain
data. Data gathering for reservoir studies and
characterization with special focus on EOR/
IOR screening is commenced at the beginning
stages of the field lifecycle. All the activities on
reservoir have to be designed and conducted
with focus on EOR methods. Rock and fluid
samples of the reservoirs need to be obtained
and high quality laboratorial tests must be
performed from the beginning of the field
development. Due to getting used to mindset
of early production of easy oil in oil and gas
industry in Iran, there is always several shortages
in data gathering and construction of valid data
bases that leads into further issues in future
plans for EOR studies and implementation. This
issue is more highlighted in the productionbased
managerial approaches in which decision
makers usually do not allocate enough time
and budgets for data gathering from various
parts of reservoirs [10] . Data such as amount of
swept oil, un-swept regions and residual oil
saturation in water/gas injection processes are
vital information that are required to be known
to increase the success of improvement/
enhancement oil recovery methods. That is
why monitoring techniques such as 4D seismic,
tracer tests and repeated well logging in
observation wells are highly important in such
processes and are usually considered as one of
the main parts of any EOR/IOR studies.
2. Most of research projects in Iran oil and gas
industry have been completed with no real
case application. The results of these works
are usually stored as leaflets and papers.
Sometimes even availability of these results
is problematic and requires a series of timeconsuming
activities inside the governmental
organizations. It is strongly required to have
a systematic plan in designing, budgeting
and conducting research-based projects in
Iran oil ministry to have fruit-full and direct
utility in Iran oil and gas industries. With a
quick glance on some of the research-based
projects, it could be concluded that several
reasons like inappropriate and non-framed
project description and scope of work, lack of
required data at time of implementation and
relying on incorrect assumptions, leads into
a situation that results are not applicable in
industry. This fact highlights the importance
of introducing an effective and efficient
framework for project scope definition and
12 OIL INNOVATORS International Journal MAR. 2018 13