ACHANGEOF
DIRECTION
A
s thedrive to tapexisting resources continues,
operatorsare looking for efficiencygains toensure
the financial viabilityof theirmature fields.
Thechallenge lies inaccessing these reserves inan
affordableway.Oneway toaddress thisproblemhasbeen to
takeadvantageof thespeedandunderbalancedcapabilities
ofdirectional coiled tubingdrilling. Adrillingcampaign
involvingaseriesof successful coiled tubingdrilling (CTD)
operationscarriedout in theNiobraraChalkdemonstrates that
newCTD technology is takingdirectionaldrilling to thenext level.
Thecampaignwascarriedoutbydirectionaldrillingspecialist
AnTechLtdwith its5 in.POLARIS
™
tool, abottomholeassembly
(BHA) forCTD thatdrillsdirectional, S-curveandhorizontalwells in
shallow reservoirs (Figure1).
ThePOLARIS tool issteeredusingasolid-stategyrodirectional
sensor, uniquelyprovidinghorizontal gyrowhiledrilling (GWD)
capability.
Hailedasanefficient, safeandenvironmentally-friendlymeansof
drilling inshallow reservoirsand re-enteringexistingwells,CTDhas
historicallybeenwithoutameans todrill largerdiameterhorizontal
wells.However,with thecompletionof theNiobraradrilling
campaign, anaffordableand field-provenalternative ischanging
that. Throughout thedrillingcampaign, thePOLARIS tool successfully
andconsistentlydrilled to follow thespecifieddirectionalpath.
TheNiobraracampaignwasdesigned todemonstratea range
of applicationsof interest tooperatorsseeking toaccessshallow
reservoirsand re-entermaturewells. Tominimisecosts, every
well’ssurfaceholewasdrilledandcasingsetusingawaterwell rig.
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