A few years ago we had a call from an oil
company in Louisiana USA that wanted a portable gas analyzer for oxygen, carbon dioxide and nitrogen for use in a large oil field of more than 200 wells. They were sampling from the top
of oil wells after a flame front had been ignited at the bottom of the well.
The subsequent discharge gas readings provided information about the status of
the flame front and the geology of the oil-bearing stratum.
The sample itself was expected to have O2 /
CO2 / CO / N2 / Ar / CH4 and traces of sulfurs & H2S. There was also a likelihood
of oil vapor and moisture. The temperature of the sample was estimated to be
200F. The sample pressure was variable between atmospheric pressure and
slightly above by a few psig.
Previously, they had been capturing a gas
sample from each well in a Tedlar bag and transporting it to a laboratory for
analysis by gas chromatograph or other methods. Once the 200 wells were tested,
the whole process would repeat again the next week.
This process had several
drawbacks:
- Very time-consuming for analyzing many
wells
- Periodic bag failures resulted in missed
tests for some wells
- Transportation costs of samples to lab
- Increased record-keeping requirements to
track bag IDs
- High cost for lab analyses
- Long time delay between extracting sample and
receiving results
- Maintenance of inventories for bags and
other associated accessories
The oil company decided to contact Nova to
investigate the possibility of using a portable analyzer for in-situ
measurement of the discharge gases instead of sending the samples to a lab. The
analysis requirement was for O2 / CO2 / N2. We can only provide O2 & CO2.
It was decided that these two gases would be sufficient for their needs. It was
also decided that an explosion-proof or intrinsically safe instrument would not
be needed in this application.
The Model 309WP was purchased with the
following features:
- Ranges: 0-25% O2 & 0-20% CO2
- Built-in pump and regulator for variable sample
pressures
- Built-in re-chargeable battery to allow field
use
- Condensate removal system to catch
condensed moisture
- Oil vapor filter to remove oil vapors from
sample gas
- Durable case, weather-proof when closed
- 4-20mA recorder output to allow use with
data-loggers if desired
A year or two after the unit was delivered,
we got it back for some minor servicing and a calibration. The company reported
that the instrument was performing well and had saved them an enormous amount
of time and money on their weekly flame front analysis. I suspect that this
unit paid for itself in less than a month. The unit was also giving them their test
results immediately, thus allowing them to take any corrective action on the
wells in a timely manner.
We don’t do a lot of business in the
petrochem market. But this inquiry was a perfect fit for us, and it was the
ideal solution for a unique application.
For information on these and other gas
analyzer systems, give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com
http://www.nova-gas.com/
