Introduction

The Petro.ai Gun Barrel workflow allows the user to quickly find the distances between offset wells perpendicular to horizontal well lateral section midpoints.

This critically important information was previously only possible to calculate using specialized geoscience software or done manually which is very time intensive. With the Petro.ai integration, we can now calculate this information directly from Spotfire:

Gun Barrel Overview

The Ruths.ai gun barrel calculation finds the distances dx, dy, and dz between the horizontal midpoints of any combination of wells. The Gun Barrel calculates the 3D distances and delivers the information in a tabular format, which is then displayed in a series of user-friendly visuals.

The calculation requires only two sets of data. Your wellbore directional surveys and the specific formation structure grids the horizontal wells lateral section is targeting.

The final result, visualized in 2D & 3D using the Ruths.ai Gun Barrel template, will look something like this.

• The top left chart shows a map view of each lateral, colored by classified formation

• The top right visual is an interactive 3D wellbore survey

• The bottom left chart shows the calculated distances in tabular format.

• The bottom right chart shows the namesake visualization, i.e. looking at the wells “down the barrel.” We also show the formations as lines, projected at the midpoint of the lateral, when surface grids are available.

How it Works

Let’s give a brief explanation of what exactly is going on.

First you will choose a selection of wells on which to perform the calculation. These wells can be anywhere in the field, in any orientation and within any proximity to each other. That being said, it may be optimal to choose wells with relatively close offsets and similar midpoints.

As seen in the example below, in the case of a group of horizontal wells, the Gun Barrel function will calculate the 3D distance from any lateral section midpoint to the next offsets lateral section midpoint.

After the Gun Barrel function is run, a data table is produced with the 3D distance of each wellbore combination’s respective lateral section midpoints, the dX, dY, dZ locations of these midpoints and flag indicating whether a formation interval was crossed between the two wellbores. Here’s a visual explanation of each calculation:

As seen in the image above, the same data is displayed in 4 different formats, a map view, a 3D view, a Gun Barrel View, and a tabular view. Notice how each view is displaying the 3D distance from each well combination’s lateral midpoint.

Now that we understand what the Gun Barrel function is calculating let’s go over the instructions and required information to perform the calculation.

Implementing the Petro.ai Gun Barrel Workflow

Required Data

The gun barrel calculation requires two sets of data; wellbore directional surveys and formation structure grids. It is also possible to run the gun barrel calculation without structure grids, but an additional data function is required.

The surveys must have X, Y, Z, MD, and a well identifier, and the X & Y should be shifted to the correct geo positions, not the X & Y offset values provided by the survey company. The formation grids must have an X, Y, Z, and formation name. It’s also important to note that the two data sources must be projected in the same coordinate reference system with Z values referencing the same datum (e.g. TVDSS). With this information the Gun Barrel function will calculate the 3D distance between the midpoints of horizontal wellbores.

After loading these data sources into Spotfire, click Tools > Subsurface > Classify subsurface intervals. Clicking this will bring up your “Classify Subsurface Intervals” window. Here you be prompted to fill in the dropdown menus with the relevant information.

XYZ Input: Map to wellbore surveys

The top left section, shown below, is used to map columns to your wellbore surveys table. Select your wellbore surveys data table, then fill in the X, Y, and Z dropdowns. Be sure to select “use active filtering”. This will allow the user to filter and mark select groupings of wells and determine the Gun Barrel distances for that select grouping.

Horizons: Map to surface grids

The top middle section, shown below, is used to map columns to your wellbore surface grids Select your horizons data table. This will be a table that has your horizon grid data points. This table should contain X, Y and Z data points for each individual horizon. See below for reference. Be sure to select “use active filtering”. This will allow the user to filter the surface grids around the wells of interest, which will significantly improve computation time.

Output: Table names and columns

The top right section, shown below, is used to configure the output table and column names. Transfer Columns are simply the additional columns that will be displayed in the output data table, check the column name boxes to include any metadata columns that will help you identify your wells.

Gun Barrel Settings

The bottom half of the window shown below enables the Gun Barrel calculations to run and allows the user to configure settings for the gun barrel.

To enable the gun barrel, check the “Enable Gun Barrel” checkbox. In the Wellbores section, select the Well identifier and MD from your Wellbore Survey data table.

Next, use the input boxes to define buffer dimensions around the lateral. This allows the user to update the dimensions around the laterals, creating a rectangular prism for the calculations. In general, the preset values are sufficient.

The right side, Gun Barrel – Output, is used to name the spacing result table generated by the calculation. Use the input box to update the table name.

At this point, you are ready to run the calculations: click the OK button.

Gun Barrel Spotfire Template

With all the proper data imported and mapped, it is now possible use the Gun Barrel workflow. It’s possible to run the interval classifier and gun barrel calculator in any Spotfire DXP using Ruths.ai software, but we recommend starting with the Gun Barrel Spotfire template, as it’s pre-configured to automate this workflow.

Select the Gun Barrel, mark a group of wells on the Map Chart, then click the “Update Gun Barrel” button on the left side menu. And that’s it! You have kicked off the calculation for the 3D distance between the horizontal midpoints of each of the selected wellbores. Just monitor the Spotfire notifications area to see when the function execution completes.

The map chart above is displaying the horizontal midpoint X Y points. Depending on your preference, you can change these to the heel or toe if you have those points available to you in your data set.

After running the gun barrel calculation, the results are displayed in four different visualizations to help the user interpret these findings. Each will be explained below.

The “Spacing Report” cross table shows a tabular view of the data. This takes each combination of wells and displays the 3D distance between each of the combination pairs (e.g. A to B, A to C, and B to C. This view also provides the distances dx, dy and dz of each of the midpoints between the well pairs, and a flag indicating whether the combination crosses a horizon interval.

A table is great for looking up specific values; now let’s look at the visual representation of the same data. The Gun Barrel diagram helps to do this. The Gun Barrel diagram displays the data in a 2D vertical cross-sectional view through, and perpendicular to, all wellborn lateral section midpoints, allowing the user to view the horizontal midpoint wellbore paths head on, (as if staring down the barrel of a gun).

With these two views it is possible to quickly interpret the gun barrel calculations and visualize the spacing results.

Lastly, viewing this data in map view and a 3D subsurface view help to further orient the user to the well’s spatial position in the field (shown below).

Note the Map chart shows the horizontal portion of each selected well, with the heel and toe points all colored by their respective formation intervals. In the above example, the black dots represent the lateral section midpoints of each well.