I-DEV0287: Deviation regarding monitoring of gas flow and the calibration of flow meters

The project proponent seeks the deviation in the monitoring parameters of registered PDD for the monitoring period starting from 29th May 2007 to 31st December 2008.
1. As per the monitoring plan of the registered PDD, gas sampling for Gas Analysis at point “A1” should be done monthly while the PP is following the quarterly sample.
2. The gas flow meter at point “A1” is not in function from 13th November 2008, and the gas flow is being calculated for this period.
ALS (AL-Shaheen) gas flow meter at NFA (North Field Alpha) (Sl. No. 51-FQI-076) is out of service due to UPS power supply interruption, PP has put the Purchase requisition (PR # 1000496469) for replacing obsolete flow meter computer component.
A Copy of the Control Room Log dated 13/11/2008 showing the reporting of that incident was verified by SGS.
As per schematic diagram given in PDD on Page 24 flow meter 62-FQI-101(before the block NGL3) measures the total gas flow that is the sum of VA1 (ALS flow) & VX1 (NFA Flow).It was verified during site visit that 12th November 2008 onwards ALS gas flow reading is calculated by subtracting NFA measured flow reading from the total gas flow readings measured by flow meter 62-FQI-101.

For the period 29th May 2007 to 12th November 2008 Comparison of ER calculation between based on ‘ALS measured flow (51-FQI-076) & ALS calculated flow has been done. On comparison it is found that difference between ‘ER based on measured flow of ALS’ & ‘ER based on calculated flow of ALS’ is 1.9 %.
As the ‘ER based on calculated flow of ALS ‘is higher so the same (1.9%) can be subtracted from the ER claimed for the period 13th November 2008 to 31 December 2008.

3. As mentioned in Section D.4 of registered PDD (UN0763); VX1 (NFA gas flow) transmitter calibration tolerance and calibration results are not recorded and hence not available. The metering systems consist of orifice plates, differential pressure transmitters, pressure and temperature transmitters. Flow is calculated using each of the transmitter inputs. Each of these require a calibration tolerance to be applied and evidence that the tolerance has been met at each calibration check are not transparent. However as per the PP the same has been performed and the results in the form of “Ok” are being recorded in the internal SAP systems.
There are two parallel trains in Total NFA Flow (VX1) from which the gas is exported to gas processing plant and the flow meter no. for the train no 1&2 is 51-FQI-012 & 51-FQI-013 respectively. NFA flow measurement accuracy has been crosschecked by comparing the flow data based on measured values(readings from 51-FQI-012 + 51-FQI-013 ) and NFA calculated flow by subtracting ALS flow from total gas flow meter 62-FQI-101 (which measure total flow) and variation has been found for most of the data is ±1% ) so same can be accepted. This analysis was done till October 2008 and the ALS flow meter was working till 12th November 2008.

Deviation does not require a revision of monitoring plan or the changes from the project activity as described in the registered PDD.

1. As PP has used the least composition values for the emission reduction calculations among all the quarterly measured values corresponding to June 2008 composition which is 0.712 KgC/m3 (As Gas composition is measured quarterly, according to different measured values of gas composition June 2008 value corresponds to least value of total carbon content. In absence of the actual measured composition carbon value corresponding to June 2008 value is used which makes this emission reduction more conservative). The ER calculated for the monitoring period by this conservative approach is less than the ER calculated for the months where actual measured gas composition is available.
Comparison sheet of ER for 7 months based on measured composition of the Gas and on the least Carbon value (June 08 composition value) is attached herewith as Att # D-01-3, The calculations were verified by DOE.

2. As the ‘ER based on calculated flow of ALS ‘is higher so the same (1.9%) will be subtracted from the
ER claimed for the period 13th November 2008 to 31 December 2008. Hence there will be no impact
on the Emission reduction.

3. There will be no impact on the ER values as the flow measurement is reliable.