Manage hydrogen sulfide in sour wells
Hydrogen sulfide is naturally produced from the Eagle Ford Shale. The
levels can range from a few ppm up to 20,000-ppm hydrogen sulfide and must be
reduced to below pipeline gas specifications, which are typically less than 4
ppm. In addition to reducing product value, hydrogen sulfide exposes producers
to environmental and safety risk and increases the chance of corrosion.
In one field, production flows through a three-phase allocation
separator where gas discharge is comingled with other gas production streams
and sent through a custody transfer to a third-party midstream company. When
the midstream company altered the incoming gas stream KPIs, the cost of the
producer’s H2S scavenging program significantly increased.
Apply HR-2635 hydrogen sulfide scavenger to treat gas, reduce
costs
The operator tasked Schlumberger with lowering overall treating cost and
improving the treating efficiency of hydrogen sulfide. Schlumberger recommended
HR-2635 hydrogen sulfide scavenger, a concentrated triazine formulated to
convert H2S into a water-soluble, noncorrosive, and nontoxic
product.
HR-2635 scavenger is formulated to reduce the potential for calcium
carbonate scale precipitation common with most triazine products by
incorporating a thermally stable phosphonate scale inhibitor into the finished
formulation.
The team provided targeted, direct injection of HR-2635 hydrogen sulfide
scavenger and implemented a robust monitoring and optimization program.
Reduced H2S levels to gas pipeline specifications
Schlumberger injected HR-2635 scavenger into two individual gas streams
and a comingled gas header system upstream of the custody transfer with
production flow rates ranging between 36 and 43 MMcf/d and H2S
levels ranging from 80 to 95 ppm. HR-2635 scavenger effectively reduced
H2S levels to the required gas pipeline specification while
maintaining process H2S scavenging efficiency. The application also
reduced the producer’s chemical expenditure by 56%.
