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Dynamic Data Analysis – v5.12.01 - © KAPPA 1988-2017
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Fig. 3.E.13 – Sensitivity to the Lambda factor
3.E.11
Reporting Guidelines
A typical interpretation report will be split into two components: the ‘mechanical’ part,
basically the result tables and plots generated, directly or indirectly, by the Pressure Transient
Analysis package, and the ‘verbose’ part, where the engineer will report the objectives, the
operations, the interpretation, the confidence one could have on his interpretation, and
possible recommendations for well treatments and/or future tests.
There has never been an industry standard for reporting, except the Canadian EUB format that
is restricted to very basic results. Typically, professional interpretation reports will be
generated with two possible set-ups:
A header document, from a word processor, with some ‘copy-paste’ of plots and results
from the PTA software, but with most of the ‘mechanical’ report delivered as an annex.
An integrated document, typically from a word processor, where some plots and tables are
dynamically connected to the PTA software using some OLE or COM automations. The
advantage of this solution is that it is much more flexible. Once a model template has been
set up the reporting process will get shorter and shorter from one interpretation to the
next.
In any case the engineer must keep in mind that an interpretation is, at best, a best guess at a
given time, and ‘truth’ can evolve with time. The key word here is ‘interpretation’.
‘The reservoir is a circle of radius 4123.93 ft’.
This is probably the worst possible statement we can imagine in PTA. The reservoir is very
unlikely to be an exact circle. What we have in PTA is a range of models that we KNOW to be
over-simplified. We simplify to turn the qualitative into quantitative, and one must always be
factual. Also, the number of significant figures of a result must be reasonable, or at least not
ridiculous. It is not because the nonlinear regression finished at a given number that we must
keep all the significant figures of this number. So a much more reasonable statement would
be: ‘If we consider that the late time behavior is linked to a close system, a reasonable match
was obtained with a circular reservoir with a radius of 4,100 ft.’
‘The more I know about well testing, the more I worry’. H.J. Ramey Jr, 1989