A bubble map displays a circular graph - effectively a pie chart - at a point location, with the scaling of the circle and it's pie segments based on some attribute of the data. Typically the point locations are downhole locations on wells.
Bubble maps are a great way of graphing production, fluid property, or other information for distributions of wells or other point data on a map. In Petrosys you can create bubble maps from data in culture files, Petrosys well data files, or from the many Oracle databases accessible through Petrosys direct connections.
The example shown here consists of two bubble map layers overlaid, an outer transparent yellow one with a scaled size, and an inner pie using a constant size but having multiple attributes.
There are two variants of the Petrosys bubble map function. The recommended variant is the Display/Bubble-Map option in dbMap, which is either accessed through site specific desktop options, or through the dbMap option in the pseis_db front menu. Display/Bubble-Maps in mapping/Interactive will only display data from Petrosys culture files, and does not support all color options: it's the intent to replace this with the full dbMap functionality, but we'd like to ensure that we can support legacy .map files if we do so.
If you haven't got access to dbMap or the pseis_db menu, then read the technical note on 'pseis_db enables dbMap options' or call Petrosys. We can now provide dbMap functionality without your having to install Oracle or to have access to Oracle databases.
In a bubble map you can use both the absolute size of the 'bubble' circles and the relative proportion of the pie segments to represent information.
Any single bubble map layer that includes more than one attribute to be graphed will automatically be drawn as a 'pie chart', with the numeric values of each attribute being used to work out the proportion of the 'pie' allocated to that attribute. If you've only got attribute data for 'part of the story' and want to fill in the rest of the circle with data not available in your source, then you can create a formula to compute the remainder. For example, if you've got a percentage value for water saturation (SW) then you might want to specify a formula for the hydrocarbon such as 100-SW .
Bubble sizes can be scaled either on diameter or on area, or can be set to a constant. In general Petrosys recommends scaling on area as this is more visually representative of the actual variation in magnitude of the data. The scale is specified by giving a 'reference value' that has a standard 'reference diameter'. The reference value is compared to the sum of all the attributes on the point being displayed to compute a size. Scaling is therefore only appropriate for values such as production figures that actually vary from point to point. If your attributes are percentages that all add up to 100%, you'll get bubbles all of the same size.
The full range of Petrosys graphics fill options, including transparency, is available for bubble shading. To convey an additional dimension of information you can also make the colors of bubble segments dependent on the attribute values themselves, using a color gradient or individual color ranges.
|Bubble map from a well data file using the total depth for both scaling and to select a solid fill color.|
Petrosys supports direct construction of bubble maps from most of the EP well data stores that work with Petrosys. In addition you can create bubble maps from generic data in Petrosys culture files or from ASCII data files directly.
Data sets which already provide a spreadsheet or matrix of the attributes and point locations to be mapped are the simplest source to use for bubble maps. Point groups in culture files can be used, or you can directly access column based text files such as csv exports from spreadsheets through the 'Ascii file' data source.
Bubble maps can be created both from well header and from zone based data in the Petrosys well data file (wdf). In one of the examples shown we've drawn bubbles that are scaled and colored on the basis of the total depth recorded against the well header.
EP databases provide a wealth of information that can be better understood through pie charts and bubble maps. To make the structured relationships between differing types of data such as annual production and the well locations and selection criteria accessible to the matrix logic underlying bubble maps, a special form of query packaging called a 'spreadsheet template' is used.
Templates can be created and edited using the 'Admin/Reports/Templates/ option in dbMap. They are collections of queries that can be linked through common fields, such as the UWI. When executed, the template returns a matrix view of data. In the context of a bubble map, the matrix contains the attributes that can be selected for bubble scaling and coloring. A 'Preview' button next to the template selection in the dbMap bubble map dialogue lets you see the actual data accessible through the template.
|This map is created by overlaying five separate bubble map displays, each of which is based on production information for one year. The bubble segments reflect the proportion of oil, gas and water in that year, whilst the green color for the oil production varies with the actual amount of oil.|
|The preview button in the bubble map dialogue presents a spreadsheet view of the actual data accessed through the selected template.|
Over the past six months Petrosys have been experimenting with different query strategies related to bubble maps. If you are already a significant user of database sourced bubble maps then you might find it useful to show some of your templates to Petrosys support to see if we can make them more efficient by varying the underlying query strategy.