CITM: Casing Inspection Thickness Measurement
CITM comprises of four separate measurements:
- Casing Weight (lbs/ft).
- Electronic Caliper (Diameter in Inches).
- High Resolution Inductive Collar Locator.
- Downhole Temperature and pressure.
The CITM uses electromagnetic waves to measure wall thickness in ferrous, copper-bearing and HSLA steel casing.
The "Remote Eddy-Current" (REC) method is a well established
technique used in the oil and gas industry to
monitor the integrity of wellbore casings. Over a period
of years, and greatly accelerated by the presence of
corrosive liquids, steel casing will deteriorate to the point
where it is unable to be worked on with industry
standard techniques of well cleaning and rehabilitation.
There are several technologies available to estimate the
loss of metal from the casing (such as multi-arm
calipers), but the REC method is the only one which
actually responds to the total volume of steel in the
casing. An alternating magnetic field is generated at a
low frequency that is able to penetrate the steel but is
attenuated and phase-shifted due to eddy currents, and
the resulting magnetic field is measured at a remote axial
location. The amount of phase-shift is related to the
metal thickness and other parameters.
- Determine base line integrity of original casing after newly completed Well.
- Design remediation programs with the
knowledge of casing integrity prior to chemical or mechanical rehabilitation.
- Locate damaged areas where visible inspection is precluded due to scale build-up.
- Use electronic caliper to locate areas of pitting and damage that are
indeterminate by just visual inspection.
Click on thumbnail for a larger image of the Casing Inspection Log samples.
PDF of CASING INSPECTION LOG
PDF of CITM Specifications