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How to Calibrate the Encoder

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Before calibrating: Verify that the Encoder Counts decrease as the block height decreases. If not, take corrective action with the encoder hardware.

3-POINT ENCODER CALIBRATION

These instructions supersede any instructions on the screen or in the screen captures.

To calibrate the draw works encoder, select Setup → Depth → Depth Wizard

The Depth Wizard will open (see Depth Wizard screen 1).

D1

Click Next to continue with the Depth Wizard or Cancel to close the depth wizard.


D2

Depth Measuring Parameters

On Screen 2 of the Depth Wizard:

  Type in the desired Hookload trigger in klbs.

  Type in the counts per turn of the encoder being used.

  Type in the wraps per layer of the draw works (see Figure 1).

            Note:  For best results, personally count the wraps across the drum (more than once).

Click Next to continue with the Depth Wizard, Back to return to screen 1, or Cancel to close the depth wizard.

F1

D3

The Encoder Count is a hardware number corresponding to the starting point, which can be any number.

First Calibration Point

On Screen 3 of the Depth Wizard:

Have the driller bring the block to the lowest position.  The Kelly or top drive may still be attached.  This is the zero point or reference point.  Measure the height from the rig floor using a pipe tape or strap.  Enter this distance in the text box on the Depth Wizard.

When the encoder counts are no longer moving, and the block is confirmed to be in its lowest position, click Next. Click Back to return to screen 2, or Cancel to close the depth wizard.

F2

D4

Second Calibration Point

On Screen 4 of the Depth Wizard:

Have the driller bring the block to the first wrap transition (see Figure 2).  This will require someone to watch the draw works drum.  A wrap transition is the point where the wraps cross from one layer to the next layer.  Measure the height from the rig floor using a pipe tape or strap.  Enter this distance in the text box on the Depth Wizard.

When the encoder counts are no longer moving, and the block is confirmed to be in the correct position, click Next to continue with the Depth Wizard, Back to return to screen 3, or Cancel to close the depth wizard.

F3

D5

Third Calibration Point

On Screen 5 of the Depth Wizard:

Have the driller bring the block to the second wrap transition (see Figure 3).  This will require someone to watch the draw works drum.  A wrap transition is the point where the wraps cross from one layer to the next layer.  Measure the height from the rig floor using a pipe tape or strap.  Enter this distance in the text box on the Depth Wizard.

When the encoder counts are no longer moving, and the block is confirmed to be in the correct position, click Next to continue with the Depth Wizard, Back to return to screen 4, or Cancel to close the depth wizard.

Note:  If the Rig Equipment (i.e. kelly hose, top drive, etc...) prevents the driller from reaching the second wrap transition, it is sufficient to go as high as the block can go with the current limitations.  Measure the height from the zero point and continue as above.

D6

Save

On Screen 6 of the Depth Wizard:

Type the name under which to save the calibration that has just been completed.  This name will be used to restore the calibration later, if something should go wrong.  Choose a name that will be meaningful to other users.  For example, the screen capture here shows the name of the rig and the date of the calibration.

Finally

Have the driller bring the block back to the zero point once more.  Select the Corrections tab on the Depth Configuration form.  Measure the height with a pipe tape or strap.   Enter this distance in the Block Height text box (see Figure 5).  Click Set.  Confirm the change.

F5

* Enter the correct Block Height click set

Last Updated on Wednesday, 07 May 2014 18:23