(THPS) is used as a bactericide in the Skjold / Gorm oil production systems in
the Danish sector of the North Sea. A reduction in H2S
generation downhole due to THPS treatment resulted in savings on H2S
scavenger consumption. In addition, use of THPS provides other benefits
which are discussed in the paper.
THPS treatments are compared with conventional bactericidal
treatments and it is demonstrated how downhole injection of THPS retards the
growth rate of Sulfate Reducing Bacteria (SRB) and the rate of
H2S production. THPS treatment resulted in a change in the
downhole bacterial population, evidenced by changes in the sulfur isotope ratio
of the produced H2S .
Re-injection of produced water with low H2S
concentrations increases the potential for iron sulfide (FeS) deposition, both
in topsides and downhole. THPS changes both the physical form and the
bacterial content of the FeS deposits. Removal of the deposits with acid is
facilitated by THPS which exhibits FeS dissolving capabilities. Field tests
have verified the effect.
Venue: Corrosion NACExpro 2000,
Authors: J Larson, P F
Sanders, R E Talbot
NACE Paper No:
Date: March 2000