assessment of the unknown should be included in any
possibility analysis. It should be accepted that the
unknown is largest in the frontier phase, but the
learning process should continue and significant
breakthroughs can occur after long time. The analysis
should always be based on open perceptions of reality.
Facts and successful ruling models will always contain
the risk of shadow for the possibilities.
26.3 Operation
In implementing knowledge-based exploration
strategies in frontier areas the larger prospects, preferably with stacked play possibilities, are selected first
for drilling (Fig. 26.6). In addition the conditional
links between alternative prospects should be assessed
prior to selecting the drilling sequence. The first well
on a structure will be located so it can test the reserve
potential necessary for a commercial development. In
addition it should secure as much new geological
information as possible that will be relevant for a
rapidly improved understanding of the whole area.
A conscious data acquisition strategy is necessary
for securing fact-based subsurface knowledge creation. The basic principles for acquisition of data
should be:
• Sampling of drill cuttings
• Coring through reservoir sequences and hiatuses
• Continuous processing of all petrophysical data
during drilling
• Sampling of fluids
• Production testing to understand reservoir
continuity
During the operations it is important to continuously relate new data to a maximum number of
parameters in relation to the models that were used
as a basis for the prospect evaluation. It is imperative
to continuously adapt the operation to the reality
revealed during the drilling progress in order to enable
corrective actions to be taken early. Changes in the
perceptions of reality are most efficiently done by the
people that formulated the basic concepts before drilling. These people have the necessary knowledge
about the simplification process behind the volumetric
models and play types used.
0.0
0.25
0.5
0.75
Avaldsnes
before Luno
2004 Luno; 0,38
2007 Avaldsnes
after Luno; 0,45
P success
- always
- usually
- general
- by and large
- more than not
- half the time
- often
- sometimes
- occasionally
- has happened
- never
- impossible
Probability assessments:
The simultaneous presence of
reservoir, generation, migration
and trapping of petroleum
● The same facts can support
alternative possible models or scenarios
● Stochastic modelling based on independent
parameters is no substitute for thinking
● Decisions reflect the input that is always
insufficient in relation to the truth
● Probability analyses are time contextual
Fig. 26.5 Probability analysis is a subjective tool. The scientific relationship between the various factors related to petroleum generation, migration and trapping has to be understood.
The successful Luno (Edvard Grieg) discovery changed the
Avaldsnes (Johan Sverdrup) prospect to a high possibility
prospect
642
H. Chr Rønnevik
possibility analysis. It should be accepted that the
unknown is largest in the frontier phase, but the
learning process should continue and significant
breakthroughs can occur after long time. The analysis
should always be based on open perceptions of reality.
Facts and successful ruling models will always contain
the risk of shadow for the possibilities.
26.3 Operation
In implementing knowledge-based exploration
strategies in frontier areas the larger prospects, preferably with stacked play possibilities, are selected first
for drilling (Fig. 26.6). In addition the conditional
links between alternative prospects should be assessed
prior to selecting the drilling sequence. The first well
on a structure will be located so it can test the reserve
potential necessary for a commercial development. In
addition it should secure as much new geological
information as possible that will be relevant for a
rapidly improved understanding of the whole area.
A conscious data acquisition strategy is necessary
for securing fact-based subsurface knowledge creation. The basic principles for acquisition of data
should be:
• Sampling of drill cuttings
• Coring through reservoir sequences and hiatuses
• Continuous processing of all petrophysical data
during drilling
• Sampling of fluids
• Production testing to understand reservoir
continuity
During the operations it is important to continuously relate new data to a maximum number of
parameters in relation to the models that were used
as a basis for the prospect evaluation. It is imperative
to continuously adapt the operation to the reality
revealed during the drilling progress in order to enable
corrective actions to be taken early. Changes in the
perceptions of reality are most efficiently done by the
people that formulated the basic concepts before drilling. These people have the necessary knowledge
about the simplification process behind the volumetric
models and play types used.
0.0
0.25
0.5
0.75
Avaldsnes
before Luno
2004 Luno; 0,38
2007 Avaldsnes
after Luno; 0,45
P success
- always
- usually
- general
- by and large
- more than not
- half the time
- often
- sometimes
- occasionally
- has happened
- never
- impossible
Probability assessments:
The simultaneous presence of
reservoir, generation, migration
and trapping of petroleum
● The same facts can support
alternative possible models or scenarios
● Stochastic modelling based on independent
parameters is no substitute for thinking
● Decisions reflect the input that is always
insufficient in relation to the truth
● Probability analyses are time contextual
Fig. 26.5 Probability analysis is a subjective tool. The scientific relationship between the various factors related to petroleum generation, migration and trapping has to be understood.
The successful Luno (Edvard Grieg) discovery changed the
Avaldsnes (Johan Sverdrup) prospect to a high possibility
prospect
642
H. Chr Rønnevik