Mitigating long-term corrosion issues
An oil and gas producer in central Alberta, Canada, was concerned about
continuous corrosion control throughout the production field. Long-term issues
with corrosion and asset integrity from high water production percentages and
high acid gas concentrations elevated concerns about potential flowline and
production string failures.
M-I SWACO, a Schlumberger company, worked with the production company's
integrity management team to create a sound mitigation strategy that would
address corrosion issues in the field. The M-I SWACO team performed a thorough
system survey and outlined fluid parameters required for laboratory testing,
including acid gas concentrations, produced water analyses, and flow regimes.
Field production parameters were 1.0–2.0% of H2S, 0.5–6.0% of CO2,
117,000 mg/L of Cl–, at least 90% average water cut, and a
laminar flow regime.
Applying KI-3878 corrosion inhibitor
Working with the operator's production team, M-I SWACO created a
mitigation strategy for continuous application of Kl-3878 corrosion inhibitor
and a comprehensive service protocol that included evaluation of laboratory
results and monitoring. A corrosion inhibitor evaluation performed by an
independent third party confirmed excellent corrosion mitigation with the
KI-3878 corrosion inhibitor.
The customer's asset management team ranked major group flowlines into
high-, medium-, and low-risk lines. Based on lessons learned from previous
failures caused by underdeposit corrosion, pigging was optimized to improve
line cleaning and enhance corrosion control. The high-risk lines were monitored
using electrical resistance probes, iron and manganese values, and KI-3878
inhibitor residuals.
Expanding for fieldwide application
The operations staff, asset management team, and local M-I SWACO
technical and sales representatives held monthly corrosion mitigation meetings.
Discussions covered laboratory and corrosion results along with field
difficulties. As the oil production staff's confidence in the results
increased, the mitigation program was expanded to the entire field. Significant
savings stemmed from the achieved reduction in line breaks and subsequent
cleanups.
