ABB NGC8106 (natural gas chromatograph) Composite sampler replacement

ABB is pleased to introduce the NGC8106. Based upon the industry leading NGC platform,

the NGC8106 is a perfect replacement for composite samplers. The user can now enjoy

real-time data instead of monthly averages, and shipping and sample collection errors have

been virtually eliminated. Add-in a multivariable transmitter and the NGC8106 becomes a

total energy meter. Or utilize the remote communications on the 8106 to transmit real gas

quality data to an existing flow computer.

Composite samplers

Natural gas is exchanged on the basis of how much energy it

contains. One must not only know the quantity of gas going

through a receipt point, but they must also know the quality of

gas going through the receipt point.

Their most common primary metering device to measure gas

quantity is an orifice plate meter with a flow computer. The

orifice plate causes a pressure drop in the meter tube. The

flow computer senses the pressure drop and calculates the

volume based upon standard equations. Orifice plate meters

are simple, low-cost and installed on a very large percentage

of gas wells.

For gas quality, a gas chromatograph is required to provide a

gas composition from which the heating value is calculated.

However, most sites do not have enough gas volume to

justify purchasing a chromatograph. To alleviate this problem,

composite samplers were installed on measurement sites

where the flow was too low to justify a dedicated GC.

A composite sampler is a device containing a sample bottle.

On a periodic basis, either time or volume based, the sampler

will put an aliquot of gas in the sample bottle. The sample

bottles are collected either monthly or quarterly depending

upon the sales contract, and sent to a lab for analysis.

Problems with composite samplers

Data is not real-time

Typically it takes one month to collect sample before it is sent

to the laboratory for analysis. Although the analysis probably

only takes a week, it could still be another three weeks before

the technician is back at the site to collect the next sample

bottle. By the time the gas quality data is entered into the flow

computer it could be anywhere from 1-2 months old.

Data is not accurate

Although the lab analysis is very accurate it is only as good

as the sample handling practices that were used to obtain the

sample. IF the sample bottle is not properly purged or clean

when it was installed then the analysis data will be corrupted.

The error gets magnified when applied across a whole month

of gas production.

Data is difficult to obtain and not cost effective

Shipping requirements and DOT regulations make it

increasingly difficult to ship samples to the central laboratory.

These problems with composite sampler had to be tolerated

because the cost of a GC was too much to put on these lower

volume stations, UNTIL NOW.

Solution: NGC8106

Data that is real-time

ABB is pleased to introduce the NGC8106. Based upon the

industry leading NGC platform, the NGC8106 is a perfect

replacement for composite samplers. The user can now enjoy

real-time data instead of monthly averages, and shipping and

sample collection errors have been virtually eliminated.

Addin a multivariable transmitter and the NGC8106 becomes a

total energy meter. Or utilize the remote communications on

the 8106 to transmit real gas quality data to an existing flow

computer.

Data that is accurate

The NGC8106 is a single stream manual calibration device, it

is intended to be calibrated monthly or quarterly, so there is no

need to leave an expensive calibration blend at each GC site.

Easy to use and cost effective

The use of the NGC8106 eliminates many of the problems

associated with composite samplers. There are no sample

transport issues, no analysis costs, no lag in getting the

gas quality information into the gas accounting system and

instant alarming of potential data loss. While the initial cost of

the NGC and its installation may be higher than a composite

sampler. The sampler’s ongoing operation and maintenance

costs make the NGC8106 a viable economic alternative.