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Downhole casing inspection using Multi
finger caliper (MFC) and Omni directionaltool (ODT)
Borislav Zivanov, Hotwell AustriaDerek Dyson, HotwellUS
Hotwell Handelsges.m.b.H
Oedenburger Strasse 6
7013 Klingenbach, AUSTRIA
Tel.: +43 (0) 2687 – 48058
Fax: +43 (0) 2687 – 48059
www.hotwell.at
best components | simple design | rigorous testing | no sacrifice to performance
1Title of the Presntation / Author
7/24/2019 Downhole Casing Inspection Using MFC and ODT - BZivanov-DDyson
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Abstract
2 Title of the Presentation / Author
• In last year MFC and ODT has been widely used
worldwide and many open question about well
conditions were successfully answered such as
corrosion, leaks, pits, mechanical damages,
position and defect of downhole equipment, etc.• This article is overview of testing, field examples
and basic theory about combination between multi
finger caliper and omni directional tool. Several
examples from test and commercial wells will be
present in text.
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Introduction
• Casing inspection measurements are used toexamine the casing or tubing in a well.
• The applications of these include the location of pits,
leaks, and holes in the casing. With MFC and ODT, a
pit on the outside can be discriminated from one theinside wall of the pipe.
• Corrosion management is an important application.
Certain surveys are necessary for proper cathodicprotection planning. Often surveys are run on a time
lapse basis to monitor the progress of corrosion with
time.
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Introduction
•Casing and tubing placed in well bores may suffer from
damage due to corrosion or mechanical distress. Corrosion is
caused by natural electrical currents that flow in the earth,
and from man-made currents from power lines and surface
equipment.
• Holes in tubing or casing caused by corrosion can seriously
affect production rates and fluid composition, resulting in
economic loss.
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Omni directional survey
5 Title of the Presentation / Author
Hotwell magnetic thickness survey determine metal loss
from pipe both from inner and outside in downhole
environment. There are several reasons for metal losscorrosion, mechanical damage, electromechanical
process and etc. Corrosion often results from one or
more of a family of electrochemical process. When ODT
survey is run in conjunction with MFC (Multi finger caliper)survey to evaluate casing loss, the surveys provide
information which indicates whether the corrosion
is internal or external.
Omni directional survey
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Omni directional survey
6 Title of the Presentation / Author
Omni directional survey• Determines casing joints of different weight.
• Locates evidence of casing defects and mechanical wear in
casing.
• Monitors progress of corrosion or mechanical wear throughperiodical survey.
• Locates severe pits or holes in casing.
• Locates casing collars or other casing string hardware
(centralizers, scratchers, baskets, packers, etc.)
• Locates the bottom of outside casing strings.• Locates the bottom of outside casing strings pipes.
• Confirms locations of perforations.
• Determines economic value of casing when considering
well abandonment.
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Omni direction tool
OMNI DIRECTIONAL THICKNESS TOOLSPECIFICATIONS
2 7/8” 3 5/8”• Tool Length: 0,85m (33,5”) 0,85m (33,5”)
• Diameter: 73 mm 89 mm
• Weight: 15kg (33lbs) 17.5kg (39lbs)
• Pressure Rating: 15000 PSI 15000 PSI
• Temperature Rating: 175°C (350°F) 175°C (350°F)
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Multi finger caliper tool
Multi-finger casing caliper logs are mechanical
casing inspection devices. Using from 24 to 56
fingers, depending on the diameter to bemeasured. The tool gives very high resolution,
radially and vertically, to identify casing corrosion
ranging from small pits and scale to axial splits.
The tool can be opened and closed downhole.
All raw data and computations are available at
the well site.
8 Title of the Presentation / Author
Multi finger caliper tool
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Multi finger caliper tool
9 Title of the Presentation / Author
Multi finger caliper tool
Cover
(A)
Roller
centralizers (B)
Cable head sub
(C)
Feeler finger
(D)
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Multi finger caliper
10 Title of the Presentation / Author
As caliper moves over casing, the feeler arms follow the contour of the
casing’s inside wall. When feeler fingers are opened or closed, themechanical actuating mechanism of the tool convert the radial
movement of the measuring finger to axial displacement of the iron core
of placement transducer. Displacement of inner core is converted to
output electrical signal as a result of the axial iron core displacement of
displacement transducer. Signal is subsequently enter A/D converter and as telemetry signal sent to surface logging equipment.
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Multi finger caliper
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MFC and ODT
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MFC and ODT
ODT vs MTT: The initial reasoning for the design of the ODT
was to replace the older style Computalog MTT tool. The tool
was being run by customers who wanted a new and improved
version that could be run digital through the caliper tool.
Below is an example showing the results when logged on the
same well.
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Case Studies
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MFC and ODT
14 Title of the Presentation / Author
MFC and ODT
Casing Wear: The following casing was logged in West
Texas. The presence of CO2 and H2S, as well as the age of
the wells, requires the constant maintenance and check of
pipe integrity. The following are screen shots of the bottom of
the casing. It is easily noticed from the caliper that the ID of
the casing is now larger than nominal pipe od. This is also
confirmed through the ODT, where the thickness clearly
mirrors the caliper results. After the completion of logging, thewell was pressure tested, in which case the pipe burst,
verifying the caliper and odt results.
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Case Studies
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Case Studies
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Case Studies
• Perforations - New: The following examplewas logged following perforating. It is easily
noticed from the caliper that the perforation
holes are clean. The odt shows noticeable
decrease in thickness across this zone as well.
• This example also displays the repeatability of
the ODT tool. Notice the odt through the
collars and through the perforated zone. This
confirms the metal loss noticed around 2764
feet.17 Title of the Presentation / Author
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Case studies
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Title of the Slide
• Perforations - Squeezed: The perforations inthe following example are known to have
been squeezed. Notice the smaller projections
of the caliper as well as the odt through this
zone. In some cases, the caliper will not read
any perforations and the results will need to
be drawn solely from the odt readings.
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Case studies
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Case studies
• Perforations - Wear: The following example was logged through
an older well with a perforated zone. The caliper and odt
showed massive wall loss through this zone.
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Case studies
• Well Completion Fixtures: The following showsan example of a gas lift. While logging the
well, the caliper showed a large diameter
which raised concern with the engineer. It was
then noticed from the odt that the wall
showed to be thicker, confirming that the
casing was not parted or damaged internally.
After discussing with the company man, it wasdiscovered that there is a gas lift installed
here, confirming our results.
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Case studies
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Conclusion
The results from the field so far have been very
positive and have proven to be a successfulmethod in monitoring and evaluating well
conditions. Each tool plays a critical role in
casing inspection analysis.
24 Title of the Presentation / Author