SURVEY
OF BURIED ONSHORE PIPELINE STATUS, ECDA SERVICES - EXTERNAL
CORROSION DIRECT ASSESSMENT
 PROTAN
SA offers SERVICES to assess OIL & GAS
PIPELINE INTEGRITY called ECDA SERVICES, including accurate
estimation of the extent of coating defects and corrosion
activity, using a fast and efficient CIS / DCVG integrated
technique, with no need to interrupt the survey or return
to defect location afterwards.
External
Corrosion Direct Assessment (ECDA) is a structured process
used to evaluate buried onshore ferrous pipeline integrity.
The ECDA goal is to enhance safety by managing the risk
of pipeline Corrosion failures while minimizing the
cost required for excavations and repairs. ECDA can
also be used where other methods such as in-line inspection
(ILI) and pressure testing are not possible or not practical.
NACE Standard Recommended Practice on Pipeline External
Corrosion Direct Assessment Methodology (RP0502-2002)
describes the ECDA process as “... allowing the
prediction of susceptible areas where Corrosion activity
has occurred, is occurring or may occur...”
Although
all ECDA techniques used for measurements are well established,
ECDA application requires specialized field equipment
and staff experienced in the collection, recording and
analysis of data to obtain reliable and meaningful results.
Both our field and professional staff are experienced
in ECDA assessment techniques. We are equipped with
the equipment for surveys and the collection of data.
Data is then analyzed by professional engineers with
many years of pipeline corrosion prevention experience.
ECDA
is a four step process: 1) Pre-Assessment; 2) Indirect
Inspection; 3) Direct Examination; 4) Post Assessment.
The list below gives an introduction to the step content:
1) “Pre-Assessment” collects
and evaluates historical data and pipeline characteristics.
Based on the information collected, the feasibility
of an ECDA application is determined. When this feasibility
is confirmed, the pipeline is divided into regions with
similar exposure and where the same indirect inspection
tools may be used.
2) “Indirect Inspection”
uses a combination of 2 or more above ground survey
techniques such as CIS, ACVG, DCVG, AC attenuation,
etc., for the identification of areas with Corrosion
activities or coating faults. Data is evaluated via
systematic analysis and high-risk areas are identified
for excavation.
3) “Direct Examination”
involves the selection of sites to be excavated and
the physical identification of defects requiring repair
or replacement.
4) “Post Assessment” evaluates
the previous 3 steps of the ECDA process and establishes
a future assessment schedule.
PROTAN
SA ECDA SERVICE has developed an integrated
indirect inspection technique merging both the CIPS
and DCVG measurements. This integrated technique allows
data acquisition of both CIPS and DCVG simultaneously.
Higher efficiency and lower survey costs are achieved
by merging both techniques.
DOWNLOAD
NACE Standard RP0502-2002 
NACE Standard RP0169-2002
|
