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OilfieldTechnology
February
2014
phenomenon, generating shockwaves and pressure. The
mechanical power generated is used for the destruction
and transport of disintegrated rocks away from the area
between the arc and the rock.
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The system allows the generation of pressurewave
mode and pulsedmagnetic field increasing the power
of generated current pulseswith a transformation in the
time of charging/discharging from four to seven orders
of magnitude (s/
μ
s), thus allowing an increase in the
instantaneous pulse disintegration effect with power
pulses in the scale of MW or GW.
Wellstabilityenhancement
ContiCase is an innovative technology forwell stability
enhancement thatworks inparallel to thedrillingprocess
– essentially creating casing in‑situ, whiledrilling, in the
drillingbit zone, ensuringmechanical stability of thewell at
all times. It is composedof a set of technological processes
that enable the creationof anear‑net shapedmetal
structure. The ITF‑facilitated feasibility project assessed the
economy and effectiveness of theprocess and evaluated the
material’smicrostructure andmechanical properties aswell
as exploring thepotential for enhancing theproperties of
ContiCase structures through the use of addedmaterials to
create aprocess thatwill form layers on thewalls of thewell.
Theapproach couldbeparticularly valuable in
unconsolidated rock formations, which canbe challengingwith
respect tohorizontal drilling, andalsooffers thepossibilityof
a reduction innon‑productive time, as it is aone‑stepprocess
undertaken simultaneouslywithdrilling. Other benefits
andapplications of this technology could include the repair
and strengtheningof existingboreholes,management of
casingwith respect to variations in thickness and strength,
well stability combinedwithopenholeproductivityand the
productionof permeable casing sections in thewellbore.
Use of this type of well stability enhancement technology
couldpotentially have amajor impact inonshorewells, but
couldhave even greater benefits for offshoredrilling. The
aim is todevelop a system thatwill be suitable not only for
usewith theplasma‑baseddrilling technology, but also in
combinationwith current rotary‑baseddrillingmethods.
Realtimedataacquisition
ThePLASMABIT system, which is basedon the introduction
of an electric arc to the rock, offers the optionof optical
emission spectroscopy, which canbe used as theprimary
diagnosticmethod for evaluationof
rock composition.
Rockdisintegration is achieved
by interactionwith the high
temperature electric arc. Themelted
and evaporated rock elements are
highly excited and emit lightwhich
is converted into a spectral pattern
that canbe used to characterise the
chemical compositionof aparticular
drilled substance. The spectrometer
software enables rock typedetection
tobeperformedby comparisonof
themeasured signal with sampled
dataof a known andpreviously
measuredpatternof rock composition
(fingerprinting).
The system canbe used to identify thepresence of
selected elements, preciousmetals or other valuable
resources, such as hydrocarbons, throughdetection
of characteristic spectral lines in combinationwith
algorithms, plasma‑generator control and resource spectral
linedatabases. It alsooffers a route to theprovisionof
information about composition in every part of theborehole,
continuously in real timewhiledrilling, andoffers the
possibility of performing online spectroscopy inharsh
andhighpressure environments at highdepths inside the
borehole.
Thejointindustryproject’sfuture
Themain goal of theplasmadrilling researchproject as a
whole is commercialisationof PLASMABIT technology based
onhigh energy electrical plasma andmanageable in‑situ
well stability enhancement. This in turnwill deliver reduced
drilling costs and associated capital expenses, aswell as
improvedoil recovery arising fromwellbore stability. Similar
tomany joint industry technology development projects,
the scope of development consists of several phases. For
PLASMABIT, the first two yearsweredesignated for the
technology development andprototyping and subsequent
phases are oriented todrilling enhancement, ContiCase
integrationwith thedrilling system, interoperability, field
tests anddifferent application areas deployment.
InMay 2013, GADrilling successfully concluded the
feasibility study facilitatedby ITF, which aimed to evaluate
thepossible application andproperties of theContiCase
technology and to set up theproduct’s development project
plan and roadmap.
The target solution shouldbring increasedROP and a
remote controlled casing‑while‑drillingprocess, delivering
enhancedwell stability for unconsolidated rockdrilling
and/or borehole repair. The ultimatebenefit of thiswill be
an improvedoil recovery factor thanks towellbore stability,
especially indifficult rock formations.
InSeptember 2013, phase twowas launched inco‑operation
with threeoil andgasoperatingcompanies, onedrilling service
companyandoneequipmentproducer. Thisphasecombines
both theContiCaseandPLASMABIT systemdevelopment;
themaindeliverableexpected inFebruary2014 isadrilling
infrastructure formore than30ftdepth. Therearea few last
slots forparticipation in theproject foroperatingcompaniesand
drilling servicecompanies thatmaybe interested in joining.
Figure3.
ContiCasesamplescreatedonannulargranitestructureformechanicaltests. Inthedrilling
industry,thistechnologywillbeusedon innerwallsofwellsfortheir immediatestabilisation.
