TRACERCO Diagnostics™ - Flow Study
Flare Gas Flow Rate Verification
The verification of flare gas flow rates is increasingly becoming a major issue for hydrocarbon producers globally, with ever more stringent environmental legislation continuing to come into effect in local regions.
A major hydrocarbon producer recently asked Tracerco to carry out a programme of flare gas verification on one of their production facilities in the North Sea. The programme involved accurately determining flare gas flow rates on both the high pressure (HP) and low pressure (LP) systems at five different process conditions:
High Pressure System:
Normal Purge; Medium Purge; High Purge and; 1MMm3 /day Purge
Low Pressure System:
Normal Purge
The TRACERCO Diagnostics™ Flow study, which utilises advanced radioisotope tracers and sophisticated detection technology, is based on a pulse velocity method and was chosen primarily because it was non-intrusive, required no system preparation and it provided immediate on-site results.
The mobile detectors, connected to a central data collection facility, were set a known distance apart. The tracer was then injected into the flare gas stream in sharp pulses using a high pressure injection system. By measuring the time of flight between each of the detectors and knowing the distance between them the velocity is calculated, which when combined with the flare vent internal diameter allowed the flow rate to be calculated.
A typical example of the results gained during the flow rate verification programme can be seen below, with tabulated results from Condition 1 beneath.
Figure 1: Typical Graphical Results from a TRACERCO Diagnostics™ Flow study
Figure 2: Tabulated results from Condition 1.
| Time (sec) |
M / Sec |
M3/hr |
|||||
| Average | 17.57 |
1.92 |
1339.30 |
||||
Error |
0.16 |
0.02 |
53.96 |
||||
% Error |
0.9% |
1.0% |
4.0% |
||||
Det B |
Det A |
time (sec.) |
metres/sec. |
M3/hr |
Date |
Run Time |
|
Run001 |
22.27 |
4.86 |
17.42 |
1.94 |
1351 |
30.07.01 |
09:42 |
Run002 |
25.45 |
7.25 |
18.20 |
1.85 |
1293 |
30.07.01 |
09:43 |
Run003 |
23.48 |
5.98 |
17.50 |
1.93 |
1345 |
30.07.01 |
09:44 |
Run004 |
22.33 |
4.87 |
17.47 |
1.93 |
1347 |
30.07.01 |
09:45 |
Run005 |
31.27 |
13.87 |
17.40 |
1.94 |
1352 |
30.07.01 |
09:46 |
Run006 |
31.51 |
13.98 |
17.52 |
1.92 |
1343 |
30.07.01 |
09:48 |
Run007 |
31.65 |
14.03 |
17.62 |
1.91 |
1336 |
30.07.01 |
09:48 |
Run008 |
38.00 |
20.40 |
17.61 |
1.92 |
1337 |
30.07.01 |
09:50 |
Run009 |
58.82 |
41.27 |
17.54 |
1.92 |
1341 |
30.07.01 |
09:51 |
Run010 |
26.81 |
9.34 |
17.47 |
1.93 |
1347 |
30.07.01 |
09:52 |
If you have a similar flare gas verification project or a flowmeter that you would like to calibrate on-line or would just like to know more about the TRACERCO Diagnostics™ Flow study technology please contact us.
