REAL RESULTS
DTS Warmback Survey Allows
Operator to Identify Injectivity Loss
without the Added Costs and Risks
of Openhole Wireline Logging
Objectives
• Determine relative injectivity profiles across a horizontal
water-injector well’s 6,000-ft (1,829-m) openhole section
without running wireline logging tools.
Results
• Weatherford performed a distributed temperature sensor
(DTS) warmback survey by installing fiber optic cable
attached to the outside of a 2 7/8-in. stinger into the open
hole below the casing shoe. Weatherford’s warmback
analysis used DTS modeling and interpretation software,
evaluating temperature measurements from each zone at
periodic time intervals after well shut-in following injection.
DTS Warmback Survey Showing the
Relative Injectivity Profile. The zone
immediately below the casing shoe
returned to geothermal temperature more
slowly than the other zones, indicating
that it had higher injectivity. Deeper
zones returned to the geothermal
temperature more quickly, indicating
lower injectivity.
Optical Sensing Data Analysis. The DTS
warmback survey is used to determine
the injectivity or production profile of the
well by measuring the relative rate of
temperature change at each zone.
Because injection wells are cooled by
injection fluids, higher injectivity zones
will take longer to return to the
geothermal temperature. Zones with low
injectivity will have less cooling effect,
resulting in a faster rate of return to the
geothermal temperature. DTS surveys
can also be performed in producing wells
where the differences between
temperature profiles at different flow
rates can be used to determine relative
productivity.
Value to Client
• Information from the DTS survey enabled the operator to
locate a thief zone immediately below the casing shoe that
was taking the majority of the injected fluid.
• Remedial action was taken based on this DTS data to
improve injectivity distribution
• The DTS survey allowed the operator to avoid the
additional costs, risks and time required for openhole
wireline logging.
Location
Offshore, Middle East
Well Type
Dual-lateral, openhole horizontal water
injector
Products/Services
DTS service using fiber optic cable
DTS service allows interventionless monitoring of the injection profile
across the well and can be measured continuously or periodically.
Weatherford International Ltd.
515 Post Oak Blvd., Suite 600
Houston, Texas 77027 USA
Tel: 713-693-4000
weatherford.com
Weatherford
weatherford.com/optics
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