IN D EX
Introduction, Step Change
Technology and Features
Rotating the Casing
DrillShoe™ I and Case Histories
DrillShoe™ II and Case Histories
DrillShoe™ III
XpandaBit™ and Case Histories
Specifications
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Weatherford products and services, please contact your authorised Weatherford representative. Unless noted otherwise, trademarks and service
marks noted herein are the property of Weatherford. The BBL stylised logo is a registered United Kingdom trademark of Weatherford
NOVEL “DRILLING with CASING”
(DwC™) TECHNOLOGY TRANSFORMS
WELL CONSTRUCTION PRACTICE.
DrillShoe II
Weatherford offers a range of proprietary drillable drill
bits, that are made up directly onto the casing using
the casing as the drillstring. This procedure
contrasts with competing drilling with casing
systems, which do not operate by rotating the
casing. These systems are complex and involve
substantially sophisticated downhole equipment.
DrillShoe III
The DrillShoe System is a step-change technology
which transforms well construction efficiency.
There are many applications for Drilling with
Casing (DwC) where operational problems can be
avoided and financial savings can be realised.
POTENTIAL APPLICATIONS
EXIST IN EVERY OIL
FIELD IN THE WORLD.
Introduction
Rotating the
Casing
What is a DrillShoe™?
DrillShoe™ is our name for a Drillable Casing Drill Bit. The DrillShoe is made up to the casing in the same way as a conventional
drill bit would be made up to a drill string. The DrillShoe has a two part construction;
1. A body made from steel, which has the casing connection and a tungsten carbide gauge section.
DrillShoe I
2. A nose made from aluminium alloy which incorporates a drillable cutting structure mounted on integral blades.
The nose and the body are threaded and locked together and the tool is supplied as a unit, as shown.
1.
2.
3.
DrillShoe II
Three cutting structures are currently available. Two of these are drillable with standard oilfield drill bits, the third is
displaced into the annulus after the casing has been drilled to total depth, removing all hard materials from the path
of the subsequent bit.
Dense, thin layer of tungsten carbide applied to integral aluminium alloy blades
Thermally Stable Polycrystalline Diamond cutting structure mounted in integral aluminium alloy blades.
PDC cutters mounted on steel blades which are displaced to the annulus by a simple pressure cycle.
DrillShoe III
Each of these cutting structures cuts the rock with a shearing action just as PDC cutters on a conventional PDC drill bit
and each tool can be drilled through with standard oilfield drill bits or another DrillShoe on casing.
The nose of the DrillShoe has drillable nozzless strategically positioned to clean and cool the cutting structure and flush
away the cuttings up the annulus.
XpandaBit
The center of the unit is fully drillable with PDC or roller cone drill bits, or with another DrillShoe. Drill out can take
between 10 minutes and 40 minutes, depending on size and style of the bit used.
The installation of a separate float collar in the casing string allows the cementation operation to begin immediately TD
has been reached, and to be completed as normal.
After ‘waiting on cement’ the next drill bit is run and drills through the shoetrack and DrillShoe before entering virgin formation.
• The DrillShoe™ System uses casing as the drill string in a similar manner to
a drill bit on drillpipe. Using a top drive, the casing is rotated. As the well is
being drilled additional lengths of casing are added.
• Once all the casing has been drilled in to the depth required, drilling stops
and the assembly is cemented in place as normal.
DrillShoe II
• The next drilling (conventional or DwC™) assembly is run in to drill out the
cement. This assembly will drill through the center of the previous DrillShoe
System without damage...typically in 10 to 30 minutes, and carry on drilling
as required.
DrillShoe III
Benefits
• Reduces rig time and operating costs.
• Reduces flat time and operational time.
XpandaBit
• Improves and simplifies well construction operations.
• Reduces hole problems.
• Eliminates casing running problems.
A Water Bushing is the name given to a crossover from drill pipe (or Top
Drive) to the Casing. It is simply a sub with a drill pipe connection (box)
up and a casing connection (pin) down which is positioned between the
Top Drive and the Casing String.
DrillShoe II
Although a Water Bushing meets all the technical requirements for
Casing Drilling, it has one big disadvantage...TIME. As drilling
progresses, every time a joint is added, one break out and two make up
operations are required. Since casing connections take longer than drill
pipe connections the time saving advantage of Drilling with Casing may
be lost.
DrillShoe III
A Water Bushing is suitable ONLY for the following applications:
• Short Casing Strings, say less than 500ft.
• Very large casing string i.e. 20”+
• Jobs where reducing flat time is NOT the primary
consideration, i.e. major hole problems.
Introduction
Casing Drilling Spear Assembly
using tools from inventory
Spacer Sub
DrillShoe I
Spear Grapple with extended
stop ring left hand release and
bi-directional slips
Rotating the
Casing
ROTATING THE CASING
Casing Spear
DrillShoe II
Double Pin Sub
Weatherford Casing Spear Assembly
Spear Pack-Off
DrillShoe III
Cut box
connection
in Bull Nose
XpandaBit
Weatherford have developed a spear that replaces
the conventional threaded crossover. Some
existing spears can be modified to make them
purpose fit for Drilling with Casing operations.
Once modified, their operation is fast and simple.
Stab the spear into the top of the casing joint
rotate a quarter turn to the left. The Casing
Drilling Spear is field proven and simple to use.
Understanding the limitations of modified
fishing spears, Weatherford developed a fit
for purpose spear for Drilling with Casing.
The casing drilling spear combines all the
required elements and with an extended
depth range.
Since January 2000, this DrillShoe System has
accumulated hundreds of successful runs to date. The
target casing running depth has been achieved on every
job. A rapid, damage-free drill out was also achieved with
the subsequent bit run.
Applications for the DrillShoe System include drilling very
soft to soft unconsolidated rock; typically surface hole.
Various product sizes are available from 95/8” to 30” casing,
drilling from 11¾” to 36” hole.
DrillShoe III
The DrillShoe System is suitable for applications with
standard “Buttress” or premium casing connections.
This tool is very aggressive and will drill quickly with low WOB. Aggressive drilling tools can generate high torque for low weight.
It is recommended that WOB be kept to a minimum until the torque response of the DrillShoe I is known.
Making Up to the Casing Drilling String
Drilling Ahead
Stand the DrillShoe box up on a rubber mat or wooden board.
Make up to normal casing torque.
Pick up and run as per normal procedure.
Always kick in the pumps and rotate before going to bottom.
Increase weight gradually to achieve desired ROP.
Remember that excessive WOB will reduce tool life.
Monitor pump pressure carefully, as an increase may indicate bit balling.
If bit balling is suspected pick up off bottom, rotate at high rpm, and cycle the pumps
several times to try to wash the DrillShoe tool clean of cuttings.
Drilling-out through shoe track and another DrillShoe tool
Drilling Out after Cementation
DrillShoe I is NOT designed to drill the shoe track.
If this is a rquirement a DrillShoe II with diamond cutting
structure is required.
Drill through the float equipment as per normal procedure.
Before tagging the DrillShoe Nose, set rotary at 20-50rpm, pump at maximum rate.
PDC can take 5-20 minutes with 1.5 - 3 tonnes WOB to exit the DrillShoe tool.
Roller Cone can take up to one hour, use higher WOB.
Be patient.
If required to ream the DrillShoe body stop rotation before pulling back.
Pump at high flow rate, rotate at about 40rpm.
Zero the weight indicator, record pump pressure and torque.
Run down slowly to tag bottom, carefully monitoring WOB, torque and pressure.
It is recommended that the first few metres are drilled down with
minimum weight to bed in the DrillShoe tool.
XpandaBit
Unpack the tool and make the following checks:
Check and record the serial number, tool size and type.
Confirm no damage to aluminium nose or cutting structure.
Check that the ports / nozzles are clear.
Remove thread protector and check for damage.
Confirm that there is no debris inside the tool.
DrillShoe III
Initiating the Drilling Process in Open Hole
DrillShoe II
Preparation Prior to Running
DrillShoe I
Never set the tool on bottom unless full pump rate and rotation have been achieved.
Rotating the
Casing
General Information and Recommendations
The central portion of the nose of the tool is constructed from aluminium alloy, which is fully drillable with any type of oilfield drill bit.
This is set with high density, HVOF tungsten carbide on the front of the blades.
Introduction
Rotating the
Casing
DrillShoe™ I - FEATURES
DrillShoe I
Drillable Carbide
High Stand-Off
“fishtail” blades with
wave cutting profile
Hydraulic optimisation
with fixed flow ports or
interchangeable drillable
nozzles
DrillShoe II
Fully drillable center
nose section
DrillShoe III
Stabiliser pads with
tungsten carbide gauge
protection
The DrillShoe II was launched in July 2000 as the second generation
tool. It is designed to drill “consolidated” formations beyond the scope
of DrillShoe I. This tool incorporates PDC cutters on the shoulder
together with a proprietary diamond cutting structure bonded onto
central “drillable” blades.
DrillShoe II
The DrillShoe II is available in a wide range of sizes from 5” to 30” and
can be run on most standard casing or liner systems. In order to
optimise the hydraulic performance of these tools, a range of
interchangeable “drillable” nozzles are available.
This tool is very aggressive and will drill quickly with low WOB. Aggressive drilling tools can generate high torque for low weight.
It is recommended that WOB be kept to a minimum until the torque response of the DrillShoe II is known.
Making Up to the Casing Drilling String
Drilling Ahead
Stand the DrillShoe box up on a rubber mat or wooden board.
Make up to normal casing torque.
Pick up and run as per normal procedure.
Always kick in the pumps and rotate before going to bottom.
Increase weight gradually to achieve desired ROP.
Remember that excessive WOB will reduce tool life.
Monitor pump pressure carefully, as an increase may indicate bit balling.
If bit balling is suspected pick up off bottom, rotate at high rpm, and cycle the pumps
several times to try to wash the DrillShoe tool clean of cuttings.
Drilling-out through shoe track and another DrillShoe tool
Drilling Out after Cementation
Tag the cement / plug and pick up a few inches.
Pump at max flow rate, rotate at very low rpm.
Gradually increase weight until progress is established.
Monitor torque carefully, if any spikes are seen or vibration noted,
pick up and re-run to bottom.
Do NOT force it, there is only 6” drilling to exit the DrillShoe
cutting segment.
Drill through the float equipment as per normal procedure.
Before tagging the DrillShoe Nose, set rotary at 20-50rpm, pump at maximum rate.
PDC can take 5-20 minutes with 1.5 - 3 tonnes WOB to exit the DrillShoe tool.
Roller Cone can take up to one hour, use higher WOB.
Be patient.
If required to ream the DrillShoe body stop rotation before pulling back.
Pump at high flow rate, rotate at about 40rpm.
Zero the weight indicator, record pump pressure and torque.
Run down slowly to tag bottom, carefully monitoring WOB, torque and pressure.
It is recommended that the first few metres are drilled down with minimum
weight to bed in the DrillShoe tool.
XpandaBit
Unpack the tool and make the following checks:
Check and record the serial number, tool size and type.
Confirm no damage to aluminium nose or cutting structure.
Check that the ports / nozzles are clear.
Remove thread protector and check for damage.
Confirm that there is no debris inside the tool.
DrillShoe III
Initiating the Drilling Process in Open Hole
DrillShoe II
Preparation Prior to Running
DrillShoe I
Never set the tool on bottom unless full pump rate and rotation have been achieved.
Rotating the
Casing
General Information and Recommendations
The central portion of the nose of the tool is constructed from aluminium alloy, which is fully drillable with any type of oilfield drill bit.
This is set with a combination of small Thermally Stable Diamond cutting elements and high density, HVOF tungsten carbide on the front of the blades.
The outer flanks have PDC cutters.
Introduction
Rotating the
Casing
DrillShoe™ II - FEATURES
DrillShoe I
Diamond cutting structure
High Stand-Off
“fishtail” blades with
wave cutting profile
Hydraulic optimisation
with fixed flow ports or
interchangeable drillable
nozzles
DrillShoe II
Fully drillable center
nose section
DrillShoe III
Stabiliser pads with
tungsten carbide gauge
protection
New cutting structure drilled up the
shoetrack and out thru’ a 9 5/8”
DrillShoe tool in 2 hours, before
going onto drill 1121ft of formation
before casing was set.
Introduction
Rotating the
Casing
DrillShoe™ II - Case History
China - World’s longest rotary DwC run
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Footage
WOB
RPM
Flow Rate
Hours
Torque
ROP
Pressure Drop
Hyd. Power
DrillShoe™ III
As a natural progression to Weatherford’s revolutionary DrillShoe
product line the displaceable DrillShoe III was developed.
DrillShoe I
Rotary Drilling with Casing (DwC™) has proven to provide operators
significant savings on both time and money in many applications. To
expand the horizons that DwC will encompass, there was a need to be
able to drill more competent formations than where previously
possible with DrillShoe I and II.
DrillShoe II
The design criteria was to develop a DrillShoe tool that would perform
like a conventional PDC drill bit, and also have the ability to be drilled
out with a PDC cutting structure.
DrillShoe III
This was achieved by placing a PDC cutting structure over a
pressure-cycled aluminium “piston”.
A simple pressure cycle results in the cutting structure being displaced into the annulus and leaves the casing ready for cementation.
Drilling can then resume using a conventional PDC or another DrillShoe assembly.
PICK UP OFF BOTTOM
DROP AND LAND BALL
APPLY PRESSURE AND AT
1500psi PISTON BEGINS TO MOVE
DOWNWARDS AND LOCKS OUT,
EXPOSING CEMENTING PORTS.
The DrillShoe III animation will run better if all files on CD have been saved onto the hard drive
Press ESC at any time to quit animation
Introduction
Rotating the
Casing
XpandaBit™ System
INNOVATION LEADS
TO EXPANSION
DrillShoe I
Designed to overcome both reliability and capacity
problems the XpandaBit System is a mechanical
device, incorporating as many features of a standard
PDC drill bit as possible whilst drilling a 40% enlarged
hole size.
DrillShoe II
Its performance characteristics are designed to mirror the
existing BBL PDC bit range, as regards ROP, steerability,
and longevity.
Slimhole Construction Programs
Drilling Unstable Formations
Drilling With Casing
Under Reaming
Constructing Oversize Wellbores for
Expandable Tubulars
APPLICATIONS FOR THE
XpandaBit System
ARE NUMEROUS
Introduction
Rotating the
Casing
STEP CHANGE TECHNOLOGY
The XpandaBit™ System has been conceived after analysing
various customer requirements to drill “oversize” wellbores.
DrillShoe I
Oversize wellbore construction is required in order to overcome formation related
problems such as swelling shales, or shifting salts, as well as accommodating the
need for ‘slimhole’ construction or casing program optimisation.
DrillShoe II
A means of drilling wellbores up to 40% larger in diameter than the “pass through” size
of the last casing string has now become an industry requirement.
DrillShoe III
Traditional tools for this job have been “hole opener” devices and bi-centre drill bits.
Both of these systems have limitations. Whilst the reliability of hole openers has never
met expectations, most bi-centre products are designed to drill only 20-25% larger
wellbores.
Once the bit has drilled the required section length (with the 40% enlarged wellbore)
the bit will collapse back down to its original size for recovery, through the restricting
“pass through” diameter, back to surface.
XpandaBit
Future designs will be capable of drilling out the shoetrack.
The Xpandabit System is one example of Weatherford’s “step-change” innovations in drill bit technology.
OPERATION
• The XpandaBit™ System comprises of a body (head) having four or more arms (blades).
DrillShoe I
• These arms are hinged and are attached to the internal pivot housing to provide a split crown
profile.
• Displacement of the outer cylinder by hydraulic pressure causes the blades to
move between the open and closed positions. An internal compression spring returns the
tool to the standby closed position when pressure is removed and weight not applied.
DrillShoe II
• The tool is hydraulically actuated, due to a pressure drop created by throttling the flow
of drilling fluid by nozzles in the crown of the bit.
• Applying weight to the tool tends to expand the blades, but is not the principle
operating feature.
DrillShoe III
• This will ensure that the bit drills the intended oversize diameter at all times when the bit is
expanded.
• Fail safe blade closure when pulling out of hole.
XpandaBit
• The blades are constrained within the slots in the crown for greater rigidity. Guide
pins located in slots machined in the blades ensure that the blades return to the
closed position when circulation stops.
500 TO 1600gpm (1893 TO 6050l/min)
UP TO 1500psi (UP TO 103bar) (UP TO 10340kPa)
XpandaBit
CIRCULATION RATE
PRESSURE DROP ACROSS BIT
Introduction
Rotating the
Casing
XpandaBit™ CASE HISTORY
DrillShoe I
DrillShoe II
Indonesia
Attaka L-32HZ
362ft (110m)
0.62hr (on bottom)
6.2 - 6.8 klb
210 (motor & rotary)
584ft/hr (177m/hr)
Normal ROP in this area was 350ft/hr.
Excellent performance
OTHER PRODUCTS OFFERED
Lateral Jet™ PDC Bits - High performance drill bits
SlickSleeve™ - Torque and Drag reduction systems
ReamerShoe™ - Casing guide and reaming tools
DiamondBlade™ Stabilizer - long life stabilizer
GaugeAlert™ - Drill Bit gauge wear indicator