Page 27 - KAPPA - Ecrin v4.30 tutorials

Ecrin v4.20 - Doc v4.20.01 - © KAPPA 1988-2011 Ecrin Guided Session #1 • EcrGS01 - 25/36
The objective of a derived channel is to create an output data set resulting from n input
channels. Writing ‘Y’ the Y values in the inputs, the values of the new channel are defined as:
Ynew[t]= f(Y1[t], Y2[t], Y3[t], …, Yn[t],a1,a2,…, ak).
Where the parameters ‘a1’… ‘ak’ are user defined constraints.
In this particular case, the channel is defined in such a way that the resulting ‘corrected
production oil rate’ channel is set strictly to Zero whenever a shut-in is detected in the build-up
indicator channel, and will leave the rate as it is originally in ‘raw production’ anywhere else.
As a derived channel, the corrected production would be extended automatically as the input
oil rate gets updated via the database. All we would need to get this channel up-to-date is to
pick the future build-ups so that the build-ups definition is up-to-date.
Fig. D01.6 • Real rates; BU Indicator; Corrected rates
You can select the Plot view for Well#1 , select ‘raw data production oil rate, ‘corrected
production oil rate’ and ‘shut-in indicator’, to view the difference between the original
production and the modified one. A blown-up view at the beginning of one of the longest build-
up is presented on the Fig. D01.6. Note that the corrected production is a representation of the
surface rates. When downhole rates are present and we have soft shut-ins of the kind above, it
may be preferable to define the build-ups only at the time when the downhole rate vanishes.
This is beyond the scope of this session.
By applying this formula we can see here that the rate now is strictly zero when the build up
indicator is 1 (means that a shut-in is selected), eliminating thus potential noises when there is
no flow, and strictly cut to zero at the start of shut-in for synchronization with pressure
history.