1. Feature Description and Setup Instruction
By default, it is assumed that:
- The pressure in the column has settled within Transmit Delay Time (TxDT) after Flow goes High.
- The Surface Receiver will have no issues attempting to decode the sync after Receive Delay Time (RxDT) and/or TxDT has elapsed.
Figure 1
These assumptions, though stay true most of the time -does not cover cases when the system is losing fluid or when pressure is taking longer than TxDT to stabilize. In such conditions it becomes cumbersome for the Surface Receiver and MicroPulse to be in Sync and decode data. To handle these outliers, it is desirable to use additional trigger(s) to provide the decoder with the best possible chance to synchronize and decode MicroPulse / Mud Pulse Transmitter.
In addition to telemeter-ing data just off Flow transitions, we can also program the MicroPulse to telemeter off Rotation in addition to the Flow state, as illustrated in Figure 2.
Figure 2
To enable the Rotation Trigger feature, toggle the "Telem Rotation Trigger" switch available in Eclipse Touch software, select the MWD tab, click on Editor and look in the General section. “Rotation Trigger Timeout” is a setting as a failsafe, after flow goes high and the timeout period has elapsed the tool will start telemetering to cover the case where rotation cannot be accurately sensed. You can set this to a limit you feel comfortable with from 30 – 360 seconds.
While setting up a MicroPulse for Rotation Trigger the user must keep in mind Rotation Threshold and Rotation Evaluation Time values under the General section.
These settings define whether the Rotation is High or Low. MicroPulse is considered to be rotating if the tool RPM is greater than the Rotation Threshold value programmed for a period greater than Rotation Evaluation Time.
Note – Rotation Trigger Timeout needs to be selected between 30 -360 seconds as a failsafe for the tool to start telemetering data if it does not sense rotation.
Author:
Saravanan Pandiyan - Firmware Developer
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