Iron Sulfide
Control
Details
Iron sulfide (FeS) causes numerous production and
disposal issues for oil and gas producers. Soluble iron
reacts with hydrogen sulfide (H2S) to form FeS. FeS
can plug off pore spaces and perforations downhole,
reducing production. It can act as a nucleation site
for other deposits to form, such as carbonates
and paraffin. It can damage and foul pumps and
equipment both downhole and on the surface, causing
costly premature failures and subsequent well and
reservoir remediation. The black water caused by
FeS in solution requires special processing to final
disposition of the produced brine.
FeS molecules also become oil wet and bind together
to form the basis of “schmoo,” which is often found
in tanks and separation equipment (at the interface).
Frequently, the oil wet iron sulfide becomes an issue in
salt water disposal wells (SWD) where it plugs filters
and requires high levels of maintenance to keep the
injection wells functioning at normal levels.
The best plan to attack FeS is before it forms. Certain
classes of scale inhibitors work by binding to soluble
iron in solution, removing the threat of FeS from
forming. In addition, programs that can control the
SRB that form the H2S are sometimes effective;
however, if the reservoir is producing sour liquids and
gases, the most practical method may be to scavenge
the H2S to prevent it from reacting with the metal in
the system and free iron in solution.
Water Technologies & Solutions provides detailed
assessments of your production system to determine
the best approach in controlling FeS to reduce costs
and enhance production. Applying our expertise, the
solutions are designed to reduce the formation of
FeS and H2S, reduce equipment failures and fouling,
prevent “black water” from surfacing, decrease the
usage of other chemicals in the system used to treat
the effects of FeS, and reduce associated HSE issues.
In addition, by applying the right solution and reducing
blockages and failures, hydrocarbon production is
optimized to meet or exceed production objectives.
