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Oilfield Technology
September 2016
Regarding assetmanagement, manually tracking equipment is no
longer an issue. Clients can view the locations of various equipment using
GPS. Historical operating records are catalogued and easily accessed for
utilisation reporting.
Maintenance alerts let the driller knowwhen equipment reaches
maximumperformance capacities, or other customalert settings, to avoid
damage to equipment. Additionally, seeing actual equipment health
statuses keeps drillers from interrupting timelines to have equipment
inspected and checked unnecessarily.
ARCFit enables users to viewhistorical data and real time data to
provide a diagnosis of rig equipment. Alarms can be programmed at
a specified threshold to notifywhen the equipment is exceeding an
acceptable limit. The driller is then able tomodify operations to prevent
any unnecessary non-productive time (NPT).
In order to avoid taking up rig space, ARCFit and its physical
componentswere designed to integrate into rig equipment already
operating in the field. This also allows drilling crews to continueworking on
equipment already familiar to them. Utilising a set of small sensors placed
on and around drilling equipment, including the top drive, catwalk, mud
pump, etc., the condition of these tools is continuously tracked. Through
wireless technology, the sensors communicate to a CPU local to the rig.
With a connection to the internet, thewell site interface can connect the
office to the rig, allowing for real timemonitoring.
ARCFit is designed to be open-source, meaning it is available for
installation onmost othermanufacturers’ drilling equipment, not
just Tesco products. However, customers using the software on Tesco
equipment will see the benefits of maintenance scheduling based on the
company’s global preventativemaintenance programme. This programme
will alert personnel of upcoming and past-duemaintenance events.
Documentation and checklists are easily accessible fromthe portal, and
clients can use it to identify parts and order the necessary replacement.
Stick-slipreduction
Stick-slip is a drill string phenomenon that occurswhen the string iswound
up. One cause of this occurswhen the drill bit catches on the formation
and becomes stuckwhile the string behind it continues to rotate. When
enough rotational force has built up behind the bit, it then releases and
spins, causing a sudden burst of energy that travels up throughout the
drill string. Essentially, the same reaction can be seenwhenwinding up a
mechanical toy and then letting it go.
In the case of stick-slip experienced downhole, there is an excessive
amount of force due to theweight of the pipe and bottomhole assembly
(BHA). This release of energy causes the components of the BHA (MWD,
LWD, stabilisers) to slamviolently against the borehole. Damage to the
BHA is common in these instances and can lead to tripping out of the hole
to replace components.
The drill bit also takes punishment in instances of stick-slip. The
constant off/onmotion of the drill bit can lead to wear on the bit. This
can cause poor performance and delays, as the bit is no longer able to
achievemaximumROP. When the sides of the bit are worn down, holes
become out of gauge. Worse, a cone can come off the bit, requiring a
fishing operation and halting operations altogether until the problem is
resolved.
Drill pipe connections, aswell as all the BHA tool connections take a
beating. Connections can be over torqued leading to a twist off, reducing
the lifetime of the drill pipe. Third party service companieswill want
compensationwhen damage is done to their tools.
Today, downhole toolsmay have sophisticated sensors tomonitor
speed and/or torque of the drill string. However, thesemethods only
enable operators to react to stick-slip, which can persist through a
formation or even awell. Conversely, ARCTork™ reduces the opportunity
for stick-slip to occur before it starts. Algorithms accurately calculate
Figure 1.
ARC software provides operatorswith real time information
on the global location, operating status andmaintenance history of
their equipment.
Figure 2.
ARC software useswell plandetails and live rigdata to
accuratelymodel drill string characteristics andadjust topdrive
parameters in real time to enhance and optimise the drillingprocess.
