Computing Optimum Wellbore Paths - Downhole Survey Output

RockWorks | Borehole Manager | Striplogs | Compute Horizontal Borehole Path | Downhole Survey

This program is used to compute the optimum path for a wellbore, given a starting XYZ point, an ending XY location, upper and lower payzone grid models, and borehole curvature, smoothing, and depth increment settings.

Once the optimum path is computed, the program will create a list with the drilled depths, azimuth (bearing), and inclination (dip) for the points along the proposed well. The spacing between these points is defined by the "Depth Increments".

! Assumptions:

• The wellbore starts out vertically.
• True depth within the XYZ report is relative to the initial point – not the ground surface.
• There are no null nodes within the grids along the course of the wellbore.
• The grid models (RwGrd files) for the top and base of the payzone already exist in the project. These can be imported, or created in RockWorks using its stratigraphy modeling or other grid-based tools.

A video that demonstrates these capabilities can be viewed at: http://youtu.be/gLRuNCKhkUc

See also:

• XYZ Points to get a list of the downhole points, true depths, and formation thickness, along with the survey values
• Plot 2D Path to display the wellbore and payzone in 2D cross-section
• Plot 3D Path to display the intercept points, boring path, and payzone thickness in 3D

Menu Options
Step-by-Step Summary

Menu Options

• Initial Point: Use these settings to define the location of the start of the wellbore. These must match the coordinate system and units currently established for the other holes in the borehole database.
  • X (Easting): Click to the right to type in the X coordinate for the top of the well.
    
  • Y (Northing): Click to the right to type in the Y-coordinate for the top of the well.
  • Z (Elevation): Click to the right to type in the Z (elevation) coordinate for the top of the hole.
    
    
• Final (TD) Point: Use these settings to define the map location for the end of the wellbore. Note that the final elevation will be determined by the payzone grid models and borehole properties defined below.
  • X (Easting): Click to the right to type in the X coordinate for the end of the well.
    
  • Y (Northing): Click to the right to type in the Y-coordinate for the end of the well.
     
• Borehole Properties:  Use these settings to define the angularity of the hole.
  • Radius of Curvature: Click to the right to type in the radius of the circle that will best fit the optimal well path. The greater the value you enter, the larger the circle, and the more gradual the well curve to horizontal. Some examples are shown below.

• • Depth Increment: Click to the right to type in the depth or distance increment at which the path is to be computed. The smaller the increment, the smoother the path.
  • Smoothing Factor: Click to the right to type in the number of smoothing passes to run on the path.
    
    
• Pay-Zone: Use these settings to define the top and base surfaces for the formation of interest, into which the wellbore will be projected.
• • Superface (Top) Grid Model: Click to the right to browse for the name of the existing grid model (.RwGrd file) that represents the surface at the top of the formation of interest. This could be a surface generated using the Stratigraphy modeling tools in RockWorks, or a grid that you've imported from another source.
  • Subface (Base) Grid Model: Click to the right to browse for name of the existing grid model that represents the surface at the base of the formation of interest.
     
    

Step-by-Step Summary

1. Access the Borehole Manager program tab.
2. Select the StripLogs | Compute Horizontal Borehole Path | Downhole Survey menu command. 
3. Enter the requested menu options, described above.
4. Click the Process button at the bottom of the window to continue.

The program will compute the optimum borehole path between the starting and ending point within the specified payzone surfaces, given the borehole parameters and depth increment you specified. The report will be displayed in a tab to the right, where you can use the menus to save, export, copy the information, etc. Listed there will be:

• Drilled depths
• Azimuth and inclination of the path at that point

The depth increments at which these data are listed are defined by the Depth Increment setting defined above. These data can be copy/pasted to the Orientation table via that table's "Datasheet" button.

Back to StripLogs Menu Summary

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