High Water Concentration

Exceeding 3 lbs/mmscf water content in the common sales gas flow

The (AIT-1203) analyzer’s detection of 3 lbs/mmscf in the sales gas flow triggers an onscreen alarm in the FNNPF Control Room. In response, the Control Room Operator looks for high water content as a clue to the cause:

• If the TEG train appears to be the cause, the Control Room Operator requests the Area Operator to promptly sample the FNNPF sales gas water content at the common sales testing location. The Area Operator performs the test and radios the results to the Control Room Operator:

-If the manual sample is within 1 lb/mmscf of the (AIT-1203) analyzer reading, the Control Room Operator concludes that the (AIT-1203) analyzer is correct and begins a thorough check of the train to identify the root cause; during the investigation, the Area Operator will provide the local input/observation as the CRO investigates the root cause.

-If the sample/analyzer results differ by more than 1 lb/mmscf, the Control Room Operator has Gas Control notify FNFS Measurement personnel to perform a prompt calibration of the (AIT-1203) analyzer.

Exceeding 3.5 lbs/mmscf water content in the common sales gas flow

If the water content problem becomes more severe and the water content in the sales gas flow rises further to 3.5 lbs/mmscf, an onscreen alarm is triggered in the FNNPF Control Room. As a part of the continuing investigation, the FNNPF Control Room Operator notifies TCPL Gas Control to advise them of the problem and the actions underway to rectify the problem.

If the water content problem becomes more severe and rises to 4 lbs/mmscf in the sales gas flow, there is heightened urgency to rectify the problem. TCPL Gas Control notifies the FNNPF Control Room for further updates on when the problem will be solved. If the TEG train does not appear to be the cause of the 4 lbs/mmscf in the common sales gas flow, the FNNPF Control Room Operator:

• FNFS Measurement personnel to perform a prompt calibration of the (AIT-1203) analyzer
• asks the Area Operator to continually sample the FNNPF sales gas water content at the common sales testing location (with a maximum of 5 minutes between tests). This manual testing continues until the FNFS Measurement personnel complete the recalibration of the (AIT-1203) analyzer.

If the ongoing water content problem becomes more severe and rises to 6.5 lbs/mmscf in the common sales gas flow, the Control Room Operator responds as follows:

• The Control Room Operator notifies TCPL Gas Control to update them on the problem and the actions underway to rectify the problem.

Note: If the Control Room determines that a train’s dewpoint analyzer requires recalibration, the Control Room Operator submits an immediate emergency notification for repair to the FNNPF E/I personnel.

• The Control Room Operator closes the train’s sales gas ESD valve and diverts the train’s sales gas to flare. The Control Room Operator begins a thorough check of the train to identify the root cause and requests local input/troubleshooting assistance from the Area Operator. To verify that the problem has been rectified, the Control Room Operator requests the Area Operator to sample the water content of the train in question. If the train’s sales gas has been dehydrated to less than 4 lbs/mmscf, the Control Room Operator may stop flaring the train’s sales gas and reopen the train’s sales ESD valve to restore the train’s gas flow to sales.

If the ongoing water content problem becomes more severe and rises to between 7 and 10 lbs/mmscf in the sales gas flow, TCPL Gas Control notifies the FNNPF Control Room Operator that the FNNPF is being given a maximum of 15 minutes to rectify the problem.If the problem is not rectified in this time, the FNNPF is requested to shut in operations.

If the water content problem in the common sales gas flow reaches 10 lbs/mmscf, TCPL Gas Control notifies the FNNPF Control Room Operator to immediately shut in the FNNPF.

Note: Unlike off-spec H2S content, off-spec water content in the common sales gas does not automatically trigger a shut in of the FNNPF.

After rectifying a wet gas-triggered shut in, the train’s dead leg length of sales gas piping must to be cleared (via sweet gas purging) of the stagnant wet gas before reopening the train’s sales gas ESD valve.