Basic Processing Routines
The DDP Platform baseline allows for basic temperature corrections and re-averaging as well as the computation of temperature changes over user-defined periods or from the geothermal, or other, baseline. Time lapsed temperature data can then be plotted as sequential curves or as a colour VDL (waterfall).
Acoustic data can be normalised/averaged by channel or depth and can be converted to the frequency domain by FFT over user-defined time windows. This allows for acoustic data to be presented as a conventional waterfall plot or as a frequency distribution VDL. Acoustic RMS values can be computed for user-defined frequency bands and presented as individual curves. Figure 2 shows an example of this type of temperature and acoustic data processing and visualisation.
The baseline also allows for consecutive FFT results to be stacked in order to improve the SNR of a given acoustic feature which can be used to extract information from quiet environments.
Advanced Processing Routines
The plug-in architecture allows for new processing functions to be imported to the DDP Platform to allow for more complex routines and answer products.
Examples of available plug-ins:
- Zonal production allocation from RMS amplitudes
- Zonal production allocation from rule based temperature analysis
- K-omega: speed of sound and flow speed computation
- Event detection
- User defined computations
The architecture allows for new routines to be quickly developed in the appropriate language and subsequently loaded into the DDP Platform. A new user of the software could request a particular routine to be added allowing for a new processing step to be applied to the acoustic and/or temperature data.
Figure 2: Basic data presentation
|Track 1||Inclination angle|
|Track 2||DTS temperature data & TVD|
|Track 3||Differential temperature (10 minute, 30 minutes, and 60 minutes)|
|Track 4||RMS frequency bands|
|Track 5||Frequency distribution|
|Time Track||Imported time-based well pressure and external probe temperature data (BOTTOM)|
On accessing the software the user can select whether to access the processing environment or the viewing environment, where processed data files are already available, or directly after a processing sequence, the user can enter the viewer setup screen and define the layout of the data for visualisation. Figure 3 shows the viewer setup screen.
On the left hand pane the user has access to all available data files which have already been processed and path-selected. Each file will represent a different type of data and so can be dragged into the appropriate graphing tab on the right-hand pane. The user then has access to the highlighted data file to manipulate how the data should be presented such as curve colour and style, axis range and labelling.
Static data such as imported depth based petrophysical logs (eg. GR) and time based well data (eg. pressure) can be imported via the main menu and placed accordingly in the graphing tabs.
The well completion can be constructed by the user from a function accessible in the main menu and can be saved to file. This will place marker lines and labels overlaid on the graphs to highlight the position of key well and completion features.
Once the user is satisfied that the presentation set up is complete they can move to “view data” and be presented with the view as shown in Figure 2. The presentation template can be saved and reloaded so that similar results can be repeated.
Since the majority of distributed data will be acquired over a period of time, and the processing steps will usually focus on smaller time steps within that period the visualisation result will typically include multiple plots each representing a subsequent period in time (eg. 1 minute), it is critical that the temperature and acoustic data and the processed answers are accurately aligned in time.
The horizontal track on the output plot is time-bound and can show time-based client data such as bottom hole gauge pressure or temperature. The vertical blue line (See Figure 2) displays the point in time from which the presented data is taken. This allows the user to correlate the distributed data set and answer products to other well performance indicators, as well as correlating events to depth-based petrophysical and well construction features from track 1.
The viewer screen (Figure 2) allows the user to step through the data in time and to view the changing conditions, in doing so the user can elect to export the plots to an image file (.PNG) so that they can be used in other applications (Word, Powerpoint) or can be animated into a short video which adds the dimension of time to the data set visualisation. The user can also elect to export the content of the plot to LAS2.0 format within this viewer environment.