Specifying a well plan

A well plan, stored under the well designs folder in the JewelExplorer, describes a well, including a sequence of well targets and related turning points. After you set the location of the wellhead, the drilling constraints and the target positions, the well trajectory connecting the targets, including the necessary turning points, is calculated according to a selected drilling calculation method (fixed radius or minimum curvature). The Settings form can be used to generate or update a well or wellbore.

 

If you have selected to create a Surface well in the previous step (Create Well Plan), select whether you want the Surface location to be at a fixed location (Fixed) or Computed. When you select Fixed, the text fields below are editable. When you select Computed, only the 'DF height above GL' is editable.

Surface Well

Surface location  You can choose between a fixed or a calculated surface location for your well. When you select Fixed, all options below are editable, when you select Computed, the options below are not editable.

Fixed  The surface location of the well has a fixed Easting and Northing. Well planning must honor this location and construct the well plan accordingly. If you select Fixed, you can either specify the location via filling the Wellhead easting, Wellhead northing, GL (Ground Level) and DF height above GL fields, or you can use the Pick location option ( ) and click in the view at the location you want.

Pick location  Activate the tool by clicking on the icon. Next, in either a 3D View, 2D View, Cross Section View or Seismic View, click at the surface location where you want to locate the planned well. The wellhead easting and wellhead northing are updated on the form accordingly. To visualize the well, check the well and the wellbore in the JewelExplorer (note that you must have clicked Apply or OK at the base of the form before the well can be visualized).

Wellhead easting  Specify the easting location of the wellhead. When you pick a location, this value will be updated automatically.

Wellhead northing  Specify the northing location of the wellhead. When you pick a location, this value will be updated automatically.

Computed  The optimal location for the well is calculated based on your targets. The only field that is editable is DF height above GL.

Ground Level The surface elevation above Mean Sea Level at the location of the well. When the ground level is above MSL, the elevation is a positive value; when the ground level is below MSL, the elevation is a negative value.

Constant  Select this option when you have an offshore well. The default value is set to 0m with respect to mean sea level.

From surface Select this option when your well location is onshore and you have the ground level surface in your model. All the horizons and unconformities in your model are listed in the drop-down list. Select the surface that represents the topography of your area. Using the coordinates of the well location, the height of the drilling installation with respect to mean sea level can be derived from this surface. The surface elevation value is, together with the Derrick Floor Elevation, used to calculate the TVDSS of the well trajectory.

DF height above GL The vertical measured distance from the topographic surface to the derrick floor.

If you have selected a Sidetrack on the Create Well Plan form, you can now select the Parent wellbore from the drop-down list and specify where the sidetrack should start by entering a value in the Sidetrack MD start field.

Click Apply to create the well and keep the form open and continue working (on the next tab), or click OK to create the well and close the form.

On the Drilling Constraints tab, if you are planning a surface well, specify the Minimum KOP (depth for the kick-off point), then select a trajectory calculation method, either Minimum curvature, or Fixed radius.

If you choose Minimum curvature, you only need to specify the DLS Factor (Dog Leg Severity). DLS is the curvature of the well trajectory expressed as a certain amount of degrees per meter trajectory. A small DLS value makes a soft curve; a high value makes a very strong curve. Realistic values are, for example, 0.1 degrees per meter, which is very drillable.

If you choose Fixed radius, you can specify different Maximum DLS and Maximum inclination values for the Vertical, Landing, and/or Horizontal sections of the well. You can change the values here if desired.

Click Apply to create the well and keep the form open and continue working (on the next tab), or click OK to create the well and close the form.

Toolbar for the Targets table

On the Target tab, you specify the targets for the well.

The Targets table lists the location of the well plan targets. For a graphically planned well, the table is populated automatically.

To add a target

  1. Click the green plus ( ) icon.
  2. Select how you will specify the target locations: either use Easting/ Northing / TVDSS or Azimuth / Inclination mode. Your selection here will make some of the columns in the table inactive, as well as some of the tools in the toolbar. In most cases, you only need to work with Easting/Northing/TVDSS. When you need to force a target to a certain direction, e.g. in case of drilling safety or a geomechanical concern, you can switch to Azimuth/Inclination mode.
  3. Optionally you can adjust the name of target in the 'Name' column.
  4. Specify Easting, Northing and TVDSS, or use the Pick Location icon ( ) and click in either the 3D View, 2D View Cross Section View or Seismic View at a meaningful locations. This will populate the table with values for easting, northing and TVDSS.
  5. Specify a Type: Target, Heel, Toe or Undefined .
  6. Click Apply to save your changes and create the targets and keep the form open, or click OK to create the targets and close the form.

The columns in the Targets table that you can adjust are:

Name  Name of the target along the well trajectory. To change a target name, use a unique alphanumeric name.

Easting/Northing  Easting/Northing of the target points along the well trajectory.

TVDSS  True Vertical Depth Sub-Sea of the target.

Azimuth (GN)  Direction of the well trajectory approaching the target. 0°: wellbore approaches the target in direction towards the north; 90°: wellbore approaches the target heading towards the east.

Inclination  Inclination of the well trajectory approaching the target. Inclination is the angle of the well path with the vertical: 0°: wellbore approaches the point vertically from above; 180° wellbore approaches the point vertically from below; 90°: wellbore approaches the point horizontally.

Type  Specify the type of the target from the drop-down list.

To change the order of the targets, select them in the table and click the up or down arrows (). To remove a target, select it in the table and click the red trash can icon ().

To graphically edit your targets in the 3D View, see Graphically editing perforations, markers, targets and sidetracks.

Extend wellbore after final target  Specify a distance by which the well plan will be extended beyond the last target specified.

The Turning Points table is a brief trajectory report. It lists the location of wellhead, turning points and targets TD. The table is filled automatically once you have added the targets and clicked Apply. A warning sign (white cross in red circle) indicates that a violation has occurred somewhere. Hold the cursor over the warning sign; an explanation appears in the form of a tooltip.

The turning point data is not editable. If you want to edit your data, you can edit the targets in the Targets table on the upper part of the form. Click Apply to effect the changes. This updates the table, and recalculates the turning points.

Name  Name of the point along the well trajectory. To change a target name, use a unique alphanumeric name.

Easting/Northing  Easting/Northing of the turning point along the well trajectory.

TVDSS  True Vertical Depth Sub-Sea of the turning point.

MD  Measured Depth along the borehole.

Azimuth (GN)  Direction of the well trajectory approaching the point. 0°: wellbore approaches point in direction towards the north; 90°: wellbore approaches point in direction towards the east.

Inclination  Inclination of the well trajectory approaching the point. Inclination is the angle of the well path with the vertical: 0°: wellbore approaches the point vertically from above; 180° wellbore approaches the point vertically from below; 90°: wellbore approaches point horizontally.

DLS  Dog leg severity angle. This is the curvature that the well trajectory makes (degrees per distance of trajectory) according to the well design settings. A small DLS value makes a soft curve; a high value makes a very strong curve. Realistic values are, for example, 0.2 degrees per meter, which is very drillable.

When you are done specifying the settings, click Apply to save the changes and keep the form open, or click OK to save the changes and close the form.