English Edition (6 MB pdf) - Saudi Aramco

• Through the Bit 5 - This technique allows for logging to
take place as quickly after drilling or coring as possible.
In this method, small diameter logging tools are
conveyed through the drillpipe conduit (specially
designed drill bits with removable central inserts).
Logging tools can be dropped off, with a wireline dropoff
tool, and log data can be recorded in memory mode
as drillpipe is tripped from the well.
FIELD EXAMPLES
Small Diameter Wireline Resistivity Imaging Examples
Fig. 3. The conveyance options available for small diameter tools.
• Well Shuttle 4 - This is a conveyance method where a
string of small diameter logging tools is conveyed to TD
inside the safety of a drillpipe garage.
• Through Drillpipe Logging - This is a conveyance
technique that can be used when well restrictions,
caused by sloughing formations, ledges, and other
obstructions, make open hole wireline conveyance
problematic or impossible. With this technique, open
ended drillpipe is lowered into the well below the
zone(s) of restriction.
• CT - This conveyance employs CT to convey small
diameter logging tools into difficult to access wells.
• Slick Line - Small diameter logging tools can be
deployed on a slick line by attaching the tools directly
to the end of the line. Deployment of the tools must be
in memory mode and can be run on any slick line,
regardless of provider.
• Wireline Drop-off - This conveyance system allows for
open hole data acquisition while tripping. In this
technique, small diameter logging tools in memory
mode are conveyed downhole by wireline through the
drillpipe conduit. The logging tools pass through the
open ended drillpipe, and hang into the open hole on a
no-go at the bottom of the drillstring. The wireline
drop-off system is activated by mechanical or electrical
means, and after release, the wireline is removed from
the well. Drillpipe is tripped from the well and log data
is recovered from the memory sub at the surface upon
tripping out of the hole.
• Wireline Tractor - This conveyance is a technique where
logging tools are conveyed into highly deviated or
horizontal wells on wireline with the aid of tractors
(mechanical devices powered with electricity transmitted
through the wireline from the surface).
The well (Well A) in Fig. 4 was a re-completion candidate.
Well A was dead due to high water production. The recompletion
objectives included running a slim hole imaging
tool to help identify, characterize and isolate the fractures
causing high water production in the well. A small diameter
microresistivity imaging tool conveyed with a tractor was
deployed in the well.
The well (Well B) in Fig. 5 was a workover re-completion
well, targeting the placement of a short radius horizontal
sidetracked well, to target attic oil in the main reservoir. Due
to borehole limitation, a window was cut from the 7” liner,
and a buildup section was drilled, to the target reservoir and
cased-off with a 4½” liner. The horizontal leg of the well was
subsequently drilled with a 3 7 ⁄8” slim assembly. A small
diameter logging suite made-up of a triple combo and the
Fig. 4. Formation resistivity image from a small diameter tool (Well A).
62 SUMMER 2010 SAUDI ARAMCO JOURNAL OF TECHNOLOGY