American Oil and Gas Reporter - September 2024 - 72

SpecialReport: Pipeline Infrastructure
minimal maintenance. They have never
had to be drained, and they have never
allowed sour gas to escape.
The payback for moving from dumpand-fill
to continuous injection can be
rapid. Recently, I had a chance to work
with Midland Basin producers on two
sites that processed significant volumes
of sour gas. The traditional towers both
had to be dumped every week, which
was expensive and labor-intensive.
When calculations showed that flooded
towers would reduce chemical consumption
significantly, the producers agreed
to put in downstream separators and
switch to continuous injection. Both separators
paid for themselves in 45-60 days.
A Toolbox Approach
In certain situations, it makes sense to
stick with dump-and-fill. For example, if
a production facility barely sees any sour
gas and the tower only needs to be drained
every two months, the savings from a
flooded tower may not justify the extra
capital cost for a separator. Other sites
may lack the space for a separator.
Sometimes a site cannot accommodate
a tower at all. Instead, operators will
treat the gas by installing atomizers on a
pipeline. The atomizers break the liquid
scavenger into thousands of tiny droplets
before injecting it into the gas stream. As
with bubble towers, the goal is to maximize
the chance of a reaction occurring by increasing
surface area.
Atomizers are affordable and readily
available, so they excel in applications
with low H2S concentrations. The threshold
varies from site to site, but I often recommend
them when the concentration is
below 50 parts per million. Above that,
it's frequently worth investing in a tower
because bubbling gas through a liquid is
much more efficient than atomizing a
liquid into a gas. In fact, an atomizer will
require two or three times more scavenger
to deal with a given concentration of H2S.
For towers to be effective, they need
to be sized for the application. The ideal
size varies widely based on gas volumes,
compositions and pressures, with some
towers as small as 18 inches and others
exceeding eight feet in diameter.
Proper sizing is only the beginning.
It's also vital for the velocity of the gas
stream to fall within the expected range
so the tower has time to treat the gas effectively.
This range is similar whether a
tower is helping fuel a pipeline compressor
by treating 100 Mcf a day or supporting
a large tank battery by sweetening 18
million cubic feet of gas a day.
In some applications, high production
volumes and space constraints make maintaining
the necessary velocity impractical.
On those sites, mixers come into play.
They are not as efficient as a tower, but
they can accommodate higher velocities.
Math Matters
The good news is that treating sour
natural gas has become a science. With
basic information on the site, including
expected H2S concentrations and gas volumes
and pressures, a knowledgeable engineer
can select a treatment system and
scavenger that is almost certain to work.
That was not always the case. From
the 1990s to the early 2000s, I had many
opportunities to use MEA triazine in gas
Drilling for American
Energy Independence!
With a fleet of high-spec AC & SCR land rigs, Latshaw Drilling is positioned
to meet our customers' requirements now and for the foreseeable future.
These capabilities derive their strength from our seasoned work force who
are the backbone of our company. We take pride in our men and women
who work hard every day to bring America closer to energy independence!
Give us a call today!
Joseph Hudson | SR VP, Marketing/Sales | 281-841-5241
Leroy Peterson | VP, Contracts | 432-889-8884
Jonathan Leininger | VP, Business Development | 903-954-0820
One of America's Leading Drilling Contractors!
© 2024 Latshaw Drilling
www.latshawdrilling.com
http://www.latshawdrilling.com
American Oil and Gas Reporter - September 2024

Table of Contents for the Digital Edition of American Oil and Gas Reporter - September 2024
