KAZAKHSTAN UPSTREAM OIL AND GAS technology and R&d ...

4.2 Field management: optimised recovery including IOR/EOR
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Solutions commentary
The ultimate goal in this area is to increase
oil production from existing assets through
improvements in reservoir engineering.
Stimulation techniques are intended to restore
well productivity that has been reduced
by bottom-hole zone damage, the result
of poor well packing, asphaltene/resin/
paraffin deposits, scaling, etc. The objective
is to deal with these problems and restore
initial production and water intake capacity.
Techniques include treatment with hot water,
condensate, hydrochloric acid, steam,
surfactants etc.
To select the optimal chemical for bottom-hole
treatment, a core analysis must be carried
out and the bottom-hole zone modelled
to test the intended treatment. Based on
laboratory results and the modeling work,
recommendations can be made for pilot
testing, and thereafter a decision made for a
wider application.
Fracturing plays an important role in
improving productivity. The efficiency of
fracturing (i.e., the depth of fracturing,
filling of fractures and duration of the effect)
is dependent on the selection of the most
efficient fracturing fluid. A combination of
hydrofracturing, acid treatment and surfactants
is usual to achieve the optimum effect.
Selecting appropriate wells (with no defects
in the casing) is also important – pilot testing
should be carried out on selected wells.
Hydrofracturing monitoring, analysis and
management of all field operations are
mandatory processes. They enable the
efficiency of the technology to be determined,
the cost of the job to be estimated and deliver
G&G studies on estimated ultimate recovery
and reservoir behaviour. Based on fracturing
monitoring and analysis, the technical and
economic feasibility of fracturing the asset can
also be determined.
EOR modeling requires input data from
laboratory core analysis, deep oil samples,
samples from drill sumps (asphaltene/resin/
paraffin deposits, scaling, etc.), G&G and
other activities.
Based on the results, a model of the bottomhole
zone can be prepared and different
EOR options assessed. The selected technique
should be tested at the selected location and
based on the results a specific EOR technique
recommended for deployment.
Problems or challenges encountered may
vary, for example asphaltene/resin/paraffin
deposits, scaling, incomplete perforation of
pay zone, plugged drill sump, etc. All of
these generally result in well production and
water intake capacity decrease. To address
these challenges, well intervention will be
required, including bottom-hole zone treatment
by various fluids, chemicals, re-perforation
and additional perforation, drilling (restoring)
the drill sump, etc.
The most efficient waterflooding, reservoir
pressure maintenance or EOR technique must
be selected based on laboratory analysis,
reservoir and bottom-hole zone models and
pilot tests. Advanced waterflooding is about
changing the reservoir pressure maintenance
techniques, testing different systems and
elements subject to G&G features and
heterogeneity.
EOR is based on laboratory analysis,
modelling, pilot testing and reviewing the
various advanced technologies, including
physical, chemical and thermal techniques.
EOR gas injection is a very promising
technology, widely deployed in fields around
the world. Gases used include associated
gas, CO 2
, nitrogen, etc.
Technology and chemical have to be selected
based on the core analysis, G&G studies,
reservoir and dynamic models, pilot testing.
Following the results of all tests, and if positive
technical and economic factors are achieved,
recommendations will be generated for
specific injection techniques or combination of
techniques.
Kazakhstan Upstream oil & gas technology and R&D roadmap