American Oil and Gas Reporter - May 2017 - 56

SpecialReport: Gas Compression Technology
The Ramsey plant is located in northern
Reeves County, Tx. The Delaware Basin's
rich gas is gathered on more than 357
miles of low- and high-pressure pipelines
with inlets to the Ramsey complex, which
is operated by Delaware Basin Midstream
LLC, a wholly owned subsidiary of West-

plan to bring the facility back to full operating capacity as safely and quickly as
possible to process Delaware Basin customers' gas. The main goal was to redesign
the damaged portion of the plant within
a judicious time while enhancing process
safety, reliability and efficiency as part

"The (Ramsey plant) project team developed a design basis

and implemented a staged restart plan to bring the facility
back to full operating capacity as quickly and safely as
possible to process Delaware Basin customers' gas. The
main goal was to redesign the damaged portion of the plant
within a judicious time while enhancing process safety,
reliability and efficiency as part of Anadarko Petroleum's
culture of continuous improvement.

ern Gas Partners LP (a publicly traded
midstream limited partnership controlled
by Anadarko Petroleum Corporation).
Before the December 2015 incident,
the plant consisted of two cryogenic
trains with a total of 300 million cubic
feet a day throughput capacity, two amine
regeneration trains with a combined 1,775
gallons a minute of treating capacity, and
approximately 2,500 barrels a day of
drip condensate stabilization capacity. A
detailed post-incident assessment made
it clear that the entire inlet portion of the
plant could not be repaired and would
have to be rebuilt, including the inlet
section of the inlet pipelines, inlet receivers, slug catchers, the low-pressure
(LP) stabilizer, the LP gas compressor
and the condensate tank farm.
In addition, the two amine treating systems (475 gallon/minute and 1,300
gallon/minute capacities) were damaged
to varying degrees and required considerable repair. The Ramsey II and III cryogenic
trains sustained less physical damage, but
bringing them back on line required some
mechanical repair and extensive electrical
and instrumentation work.
Process Enhancements
The project team developed a design
basis and implemented a staged restart
56 THE AMERICAN OIL & GAS REPORTER

of Anadarko's culture of continuous improvement.
Consequently, beneficial plant design
modifications were implemented to increase safety and operability, as well as
facilitate quick startup. The inlet receiving
area was redesigned to enhance process
safety in regard to isolation and equipment
spacing. The new inlet utilized a previously
ordered slug catcher to provide superior
separation performance and reduce lead
time. The carbon dioxide treating strategy
was re-engineered for efficiency, and a
new liquids handling system's design
concept eliminated NGL trucking and
utilized existing plant infrastructure.
The plant's redesign was implemented
in phases that consisted of four cryogenic
trains with a processing capacity of 700
MMcf/d, a 1,400 gallon/minute amine
regeneration train, and 18,000 bbl/d drip
condensate stabilization capacity. Four of
the redesigned facility's cryogenic plants
are now in operation (Ramsey II, III, IV
and V), with Ramsey VI under construction
and slated for startup later this year.
Western Gas acquired the Ramsey plant
in November 2014. Before December 2015,
it had two cryogenic trains (300 MMcf/d
total capacity), the two amine regeneration
trains and the 2,500 bbl/d drip condensate
stabilization capacity. The amine treating

system initially consisted of two regeneration
trains that supplied two individual contactors
rated for 300 MMcf/d throughput. The
amine systems were separate, with gas
flow split between the units. The condensate
stabilization system was an LP singletower design that processed condensate
fluids flashed from the high-pressure (HP)
inlet slug catcher.
The system produced a recycle gas,
an off-specification NGL, and a 10-psi
Reid vapor pressure (RVP) condensate.
Both the off-spec NGL and condensate
produced from the stabilizer were trucked
from the facility. A 1,400 gallon/minute
amine regeneration unit with a 300
MMcf/d gas train, and a 200 MMcf/d
cryogenic train were under construction
at the time the fire occurred.
The redesigned Ramsey facility has
four operating cryogenic plants (Ramsey
II, III, IV and V) with 700 MMcf/d combined processing capacity, 1,400
gallon/minute amine regeneration, and
18,000 bbl/d drip condensate stabilization
with a two-tower design. It produces a
recycle gas and either a single low-ethane
Y-grade product or a low-ethane Y-grade
and <9 psi RVP condensate, depending
on the preferred mode of operation. All
products from the plant are sold through
pipelines. The fifth cryogenic plant (Ramsey VI) is under construction.
Gas, Liquids Processing
Ramsey's initial gas treating design
was based on CO2 rates from the Avalon
formations that were drilled and developed
early in the facility's life. The plant was
engineered for full removal of as much
as 6 mole percent CO2 in the inlet gas
stream to meet the outlet NGL product
specification of 500 parts per million
CO2 in ethane recovery mode. In ethane
rejection mode, partial CO2 removal was
required to meet both the outlet NGL
and residue gas CO2 specifications.
By the time Western Gas Partners acquired the plant in November 2014, inlet
CO2 had decreased to 3 percent and was
continuing to drop as a result of the exploitation of other Delaware Basin formations, primarily the oil-rich Wolfcamp
Shale. This led to an excess of amine regeneration capacity at the plant and was

American Oil and Gas Reporter - May 2017

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