This workflow allows a user to extract an average value of an attribute grid for a horizontal wellbore within a formation. The workflow assumes that the user has already created the attribute grid(s) such as porosity, water saturation, net to gross, seismic attribute, etc. In this example, it is assumed that the well bore penetrates the desired formation as it goes horizontal and remains in the formation to total depth.

  1. In the Mapping module select Display > Wells… and choose the well data source desired. Use a Data selection option such as a well list file that has the desired wells to work with. On the Paths tab toggle on the Display well paths and Path segment. For the starting wellbore interval, select the appropriate zone top of the target formation. Then set the bottom of the interval as either Bottom-hole or select another zone top.
  2. In the display list, right mouse button (RMB) click on the wellbore display and select Export Spatial Data…
  3. In the Export spatial layer window, select Output data store to be Shape file and give it a name. Change Shape type to be Line, then use Display > GIS… to display the shape file created on the map.

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    Left: Map showing horizontal well paths. Right: The Export Spatial Data window.

  4. Use the RMB on the GIS layer in the layer list and select Edit… to open the shape file in the Spatial Editor. On the map, click and drag a selection polygon so that a portion of all the wellbore line(s) fall within the polygon. This highlights the selected lines and turns them to the selection color (red by default).
  5. Once the wellbore lines are selected, go to Operations > Buffer Shapes...
    buffer_shapes
  6. In the pop-up window, set a Distance equivalent to the surface units (m or ft) that describes the drainage or sampling radius for the well. Set the Corner type and Line end type for the generated polygons. Select New layer under Select the output layer type: and Full definition under Layer Type. Under Details, set the output type as Petrosys polygon file and enter a file name. Then click Apply and Close. Select the polygon layer just created and File > Save to save to a disk file.

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    Left: The Buffer Shapes pop-up window lets you customise the buffer properties. Right: Zoomed imaged showing buffer zone.

  7. In the Mapping module open the Spatial Editor (Edit > Spatial Editor…) and select the shape file layer with the wellbore lines. The list of lines will show to the upper right of the map in the Spatial Data window. RMB click to select Export to Excel… and toggle on the Open associated program on export and All columns and rows options. This creates an Excel spreadsheet of the attribute data for the wellbores.
  8. Open the Surface Modeling module and go to Grid > Processes > Calculate Mean Inside Polygon… Select the attribute to extract the average values and select the polygon file created in Step 6. Select the desired wellbore polygons to calculate the attribute values for. Check the process output information in the process view area of the Surface Modeling window to see how many points were averaged for each polygon. If you determine there are insufficient grid points used in the mean calculation, you can go to Grid > Processes > Resample to resample the attribute grid to a smaller cell size and rerun the mean calculation of the attribute grid.
  9. Open the Spatial Editor (Edit > Spatial Editor…) again and use File > Open… to open the wellbore polygon file. This layer will now have the “mean” attribute listed in the Attributes view on the right side of the map (Spatial Data viewing area). RMB click in the Shapes area to the right of the map and choose Export to Excel… This will export to an Excel spreadsheet with the same polygon order as the previous export but the polygon names will be different.
  10. Copy the “mean” column from the exported spreadsheet to the spreadsheet in Step 7.
  11. Repeat Steps 8-10 to add additional columns average attribute values to the output spreadsheet.

The output of the workflow provides a spreadsheet of data containing the name of the horizontal wellbore and an average value of an attribute grid within a defined polygon area around the wellbore (within a geological zone).

As an example, this workflow can assist in calculating the Estimated Ultimate Recovery (EUR), OOIP or OGIP for potential horizontal infill wells in both conventional and unconventional areas of operation.