Evaluation of Multiple Geological Models Through Assisted History Matching of Appraisal Well Tests and Early Production Data
MacDonald, David
,
Marianne Espinassous, Glyn
Williams, Mark Mansfield, BP, Sunbury,
Project sanction, the most significant investment decision in
most oil and gas developments, is the decision made during the period of
greatest uncertainty for the reservoir performance prediction. As the industry
moves towards deeper water developments, the number of appraisal wells
available at sanction will only reduce. Advances in seismic interpretation can
in many cases give confidence in the structural and reservoir continuity, but
can not be relied on to provide definitive production continuity.
Frequently during the Select and Define stages of a project,
significant uncertainty remains in the definition of the geologic model.
Frequency, orientation, profile and sinuosity of sand bodies are just a few of
the reservoir parameters that need to be characterised
before a dynamic model can be built. Understanding and quantifying the
uncertainty impact on reserves, rate and NPV should be the principle aim of
model studies at this time of field life. It is likely that little can be done
to increase the confidence of a single deterministic prediction with only
appraisal data.
BP’s Top-Down Reservoir Modelling
(TDRM) philosophy and toolkit is being successfully applied to quantification
of the prediction uncertainty in projects from Appraise through to Operate.
Specific focus has been made to develop techniques for evaluating multiple geologic
models by using all available appraisal dynamic data and benchmarks to
calibrate the models.
The TDRM
philosophy is based on decision-driven analysis and quantification of the
impact of reservoir and facility uncertainties on performance prediction using
appropriate models. An appropriate model is one which fully characterises
the reservoir mechanisms which are significant to the business decision to be
made.