Like
most engineering systems, fluid flow systems such as Oil & Gas production
systems are defined by a large number of design parameters. The
engineers job is to determine which set of parameters is the best.
This can be
achieved through optimisation where important design variables are
varied to find values which maximise the value of the development.
The value will often depend on a variety of value
measures which may include Net Present
Value, Internal Rate of Return or Profitability Index. In
addition, the optimisation must also take account of constraints and technical feasibility issues.
For example,
when delivering fluids from A to B through a pipeline system where
the overall flow rate is defined (perhaps through a sales contract),
it is important to establish the optimal balance between pipeline
size and pumping costs. As the pipeline size is increased, the pumping
costs are reduced meaning that there is a trade-off to be made between
the capital costs of the pipeline and the capital/operating costs
of the pumps. Systems such as this are commonplace in gas transmissions
systems where intermediate compressor stations are used for maintaining
the gas supply pressure. In this instance the question of optimisation
reduces to the minimisation of the system Lifecycle
Costs.
However, for
upstream Oil & Gas developments, the flow rate is usually not defined
and the optimisation now becomes a trade-off between incremental
revenue and incremental capital expenditure (CAPEX). Traditionally
optimisation has relied on heuristics and engineering experience.
However, this often leads to cost reductions or CAPEX minimisation
which can produce sub-optimal solutions. In reality, optimisation
of upstream Oil & Gas production systems needs to balance the capital
costs against the revenues generated through production.
Using the latest
in Integrated Reservoir Modelling techniques,
FEESA can study the impact of important design
decisions (such as tubing sizes, number of wells, pipeline
route/size or artificial lift methods) on the production through
field life and can relate this to the true worth of the project
or Net Present Value (NPV).
To illustrate,
we provide a few case studies where FEESA staff have carried such
optimisations, providing real value back to the client:
Long
Distance Gas-Condensate Pipeline Optimisation (PDF 192K)
An Optimisation
of diameter fro a long gas condesate popeline offshore Europe, with
fixed contract quatities.
Optimisation
of Tie-Back to Existing Facilities (PDF 115K)
Analysis of various
drillilng and pipeline router options for a small development with
a constrained budget.
Optimisation
of Extension to Existing Subsea System (PDF 119K)
Evaluation of planned
extension to production system including pipeline size, gaslift
injection and insulation assessments.
If you would
like to know how FEESA can help you optimise your design: Contact
us at info@feesa.net