07 Concentric Hole Enlargement
RHINO® REAMER SYSTEM
The Rhino Reamer System is Smith Services’ latest technology
endeavor that will enable an operator to enlarge the wellbore below
a restriction. The most frequently encountered restrictions are the
drift diameter of the casing and the size of the wellhead. Both
limit the maximum outside diameter (OD) of the tools that can
pass through.
The Rhino Reamer System is capable of drilling the float equip-
ment and continuing onward to begin hole enlargement. Hole
enlargement takes place at some point below the surface. Since
the tool has to first pass through the restricted bore, it incorpo-
rates expandable cutter sets which stay collapsed while the tool is
run into wellbore. Once the tool has cleared the casing and well-
head, the cutter sets expand into the formation by utilizing the
differential pressure of the drilling fluid or pneumatic medium.
The Rhino Reamer utilizes a patented Z-Drive actuation system
that traverses the cutter sets to a pre-selected diameter, and then
hydraulically clamps them into position. This eliminates cutter block
movement and vibration, which improves PDC cutting structure life.
The actuation system uses a parallel tongue and groove (Pocket Slip
technology) profile machined on each side of the cutter block as well
as in the tool body to guide and control cutter block deployment.
The Z-Drive and cutter block system eliminates conventional hinge
pins and long cutter sets limited to only one opening diameter.
The Rhino Reamer uses a threaded sleeve inside the bore of the
tool to adjust opening diameter. Limiting the distance the cutter block
can traverse dictates the opening diameter within the designed range.
08 Concentric Hole Enlargement
The tool is dependent on hydraulic pressure to both deploy the
cutter sets and to cool and clean the cutting structure. Jet nozzles
are strategically placed adjacent to each cutter block and actually
travel with the cutter sets to ensure optimum cleaning at any open-
ing diameter. The jet nozzles open only when the cutter sets are fully
actuated, providing an indication at surface that the Rhino Reamer
is open.
Once the hole is enlarged to the desired depth, the pumps are
turned off allowing the cutter sets to collapse into the body. The tool
is then pulled out of the hole through the restricted section.
Rhino Reamer System
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Rhino Reamer Specifications
Tool Min. Hole Max. Min. Std. Fishing Max.
Series Pilot Opening Body Collapsed Fishing Neck Thru
Hole Size OD Dia. Neck Length Flow
Size Dia. Min.
(in.) (in.) (in.) (in.) (in.) (in.) (GPM)
3500 3⁷⁄₈ 4 - 4¹⁄₂ 3¹⁄₂ 3¹⁄₂ 3³⁄₈ 6¹⁄₂ 140
5750 6 6¹⁄₂ - 7¹⁄₂ 5³⁄₄ 5³⁄₄ 4³⁄₄ 18 350
6125 6¹⁄₄ 7 - 8¹⁄₄ 6¹⁄₈ 6¹⁄₈ 4³⁄₄ 18 350
8000 8³⁄₈ 9¹⁄₄ - 10 8 8 6¹⁄₂ 18 750
9250 9¹⁄₂ 10¹⁄₂ - 11³⁄₄ 9¹⁄₄ 9¹⁄₄ 6¹⁄₂ 18 750
10000 10¹⁄₂ 11¹⁄₄ - 12¹⁄₄ 10 10 8¹⁄₄ 18 1,200
11625 12 13 - 14³⁄₄ 11⁵⁄₈ 11⁵⁄₈ 8¹⁄₄, 9¹⁄₂ 18 1,200
11750 12¹⁄₈ 13¹⁄₄ - 15 11³⁄₄ 11³⁄₄ 8¹⁄₄, 9¹⁄₂ 18 2,000
14250 14³⁄₄ 15³⁄₄ - 17¹⁄₂ 14¹⁄₄ 14¹⁄₄ 9¹⁄₂ 18 2,000
16000 16¹⁄₂ 17¹⁄₂ - 20 16 16 9¹⁄₂ 18 2,000
16000 18¹⁄₂ 19¹⁄₂ - 22 16 18 9¹⁄₂ 18 2,000
Pre-job Planning and Preparation
Pre-job planning and preparation is vital to the successful deploy-
ment of the Rhino Reamer. Accurate hydraulic requirements of the
tools above and below the Rhino Reamer are critical.
Mechanical Analysis
Perform a mechanical analysis on all Rhino Reamer bottom hole
assemblies to optimize the tool and stabilizer placement.
Pre-run Checklist
Prior to running the equipment, perform the pre-run checklist.
• Review and evaluate job objectives with the on-site customer
representative.
• Verify that all necessary equipment has been delivered to the
location.
• Check and verify tool joint connections.
• Inspect all equipment for possible damage during shipment.
Inform the customer immediately of shortages or damage.
• Caliper tool, gauge drop ball (if required), and record all
equipment dimensions that will be used on the job. Record on
strap sheet.
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• Verify the pipe tally with drilling personnel and/or customer rep-
resentative to determine the starting depth for tool operation.
• Review, verify and record hydraulic requirements in order to
achieve optimum performance.
General Procedure for Making up the Rhino Reamer
Clean and grease the API pin and box connections on the mating
BHA components. If applicable, set the BHA components to be
run below the tool in the rotary table. Use lifting sub and elevators
to pick up Rhino Reamer tool and lower onto lower BHA. Make-
up to the specified torque listed in Table 1.
Table 1
Make-up Torque of Top and Bottom Subs to Rhino Reamer Body
Tool Series Description Make-up Torque
5625, 5750, 6125 4¹⁄₂ Reg. Box x 4¹⁄₂ Reg. Box 13,000 ft/lb.
8000 6⁵⁄₈ Reg. Box x 6⁵⁄₈ Reg. Box 45,600 ft/lb.
9250 6⁵⁄₈ Reg. Box x 6⁵⁄₈ Reg. Box 56,200 ft/lb.
10000, 10375 T-38 Box x T-38 Box 66,000 ft/lb.
11625 6⁵⁄₈ IF Box x 6⁵⁄₈ IF Box 97,800 ft/lb.
11750, 14250, 16000 T-20 Box x T-20 Box 107,600 ft/lb.
CAUTION: Never place the tongs over the cutter sets. See figure 3
for tong placement.
Figure 3
Tong Placement
Place tongs here Place tongs here
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Rhino Reamer Make-up and Surface Test Procedure for Lockout Mechanism and
Hole Enlargement While Drilling Only
• Pick up the pre-made up rotary BHA components to be tested,
make-up the drill bit and lower it in the hole. DO NOT make-up
the Rhino Reamer.
• Pick up and make-up a crossover sub and/or pup joint and
make-up to the top drive.
• Test the rotary steerable system and/or Measuring While
Drilling (MWD) assembly per manufacturer specifications.
• Lay down the crossover sub and/or pup joint.
• Pick up the Rhino Reamer assembly.
• Pick up and make-up a crossover sub and/or pup joint and
make-up to the top drive.
• Slack off until the Rhino Reamer cutter sets are below the
rotary table.
• Bring the mud pumps online and gradually increase the flow rate
to the pre-established value as specified in the hydraulic analysis
for drill out (H3).
• Verify that the cutter sets have not activated.
From the time the Rhino Reamer goes through the rotary table
until it reaches bottom, care must be taken when tripping in the
hole. Care should also be taken when running through diverters,
blowout preventers (BOP), wellheads and casing shoes.
12 Concentric Hole Enlargement
Drilling the Casing Shoe Track
• Lower the BHA into the hole until it reaches the top of the
cement plug.
• Tag the cement plug with the drill bit and pick up approximately
ten ft. off bottom.
• Start pumps and establish flow to the drill out flow rate as speci-
fied in the hydraulic analysis (HB3 or H3) and then rotate the
tool slowly (30 to 50 RPM).
• Increase RPM until desired operating parameters are reached.
Ream and wash down to the top of the cement. Drill the casing
shoe track with the customer specified drill out flow rate (HB3
or H3).
• Back ream and re-ream every 30 ft. of the casing shoe track
drilled in an attempt to prevent the hole from packing off.
• After the casing shoe has been drilled out and a successful
Formation Integrity Test is taken, it is recommended to drill
ahead with the Rhino Reamer closed until the tool is 20 to 30
ft. below the casing shoe while noting torque, WOB and ROP
required to drill.
CAUTION: Be aware that while drilling ahead with the Rhino
Reamer closed over an extended period of time, cut-
tings can accumulate in the upper portion of the tool,
possibly inhibiting full opening diameter.
• Lower the BHA into the hole until the Rhino Reamer is ten to 15
ft. below the casing shoe.
• Bring up pumps to shear out flow rate as established by the
hydraulic analysis (HB4). Shut the pumps off.
• The cutter blocks should be activated now. If not sure, repeat the
activation steps using the shear out flow rate (HB4).
• If unable to activate the cutter sets using the shear out flow rate
(HB4), drop the ball in the drill pipe.
Note: When using the ball drop mechanism, the Smith Services
operator is required to gauge the drop ball to ensure that
it will pass through all drill string components, i.e. float
valve, PBL sub, etc. In order to drop a ball and activate the
tool the Rhino Reamer must be located above the MWD.
• Slowly pump the ball down the drill string until the ball seats in
the catch.
• Increase the pump pressure to shear the shear pins and activate
the cutter sets.
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• A decrease in pump pressure should be seen at the surface to
signal that the cutter blocks are activated.
• Once the tool function is verified, proceed with cutout.
Note: A pull test at the casing shoe can be performed to verify
that the cutters blocks are activated.
Cutting the Shoulder
• Lower the BHA into the hole until the Rhino Reamer is ten to 15
ft. below the casing shoe.
• Rotate the tool slowly (30 to 50 RPM) and very slowly bring
pumps up to the appropriate drill ahead flow rate (H1 or
HB1) to perform the cut-out. Rotate while working the tool
up and down approximately five to ten ft. until a cut-out
is established.
Note: The time required to initiate a cut-out will vary depending
on formation type and properties.
• Establish the cut-out while noting weight and torque.
• Once the cut-out is complete, with the pumps on and the rotary
off, slowly lower the Rhino Reamer towards the bottom of the
cut-out.
• Weight should be seen on the indicator at the bottom of the cut-
out bench, verifying cutter block activation.
Note: The bit should be off bottom at this time to ensure that
the weight noted is at the Rhino Reamer cutter blocks.
• Drill off slowly while noting weight and torque.
Hole Enlargement
• With the cutter blocks activated, the pilot hole can be enlarged.
Maintain constant drilling weight.
Tripping Out of the Hole
• Perform a pull test at the casing shoe to verify that the tool is
functioning properly. Take care while pulling into the casing and
other restrictions.
• At the surface, thoroughly flush the inside of the tool and the
cutter pockets with water.
The following operating parameters will serve as a guideline for
all Rhino Reamer jobs.
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CONVENTIONAL, DRILL AND REAM, ROTARY STEERABLE SYSTEMS
BHA recommendations should be as follows:
• Ream only — An under gauge stabilizer should be run above
the underreamer at a distance to minimize lateral force at
the underreamer cutters. The assembly below the under-
reamer should be an under gauge bit or slick bullnose.
Minimum diameter clearance for either bit or bullnose should
be one inch in pilot hole. Any full-gauge assemblies will
require BHA analysis to meet lateral force requirements.
• Hole Enlargement While Drilling (HEWD) - The BHA will be
determined by mechanical analysis for lateral force requirements
and directional objectives.
Flow distribution between reamer and bit/bullnose should be
based upon application as follows:
• Ream only — Minimum of 65 percent of the total flow rate should
exit the Rhino Reamer.
• HEWD — Minimum of 20 percent of the total flow rate should be
directed to the bit. The balance of the flow rate should be divided
between the bit and Rhino Reamer, based on the area of formation
removed by each.
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Table 2
Recommended HEWD Flow Distribution
Tool Series Min. Pilot Hole Opening Dia. % Flow to Bit % Flow to
Size (in.) (in.) Rhino
53/4 61/2 88 12
5625
53/4 7 71 29
6 61/2 88 12
5750
6 71/2 71 29
61/4 63/4 85 15
6125
61/4 81/4 66 34
83/8 91/4 85 15
8000
83/8 10 76 24
91/2 10 90 10
9250
91/2 113/4 73 27
101/2 111/4 90 10
10000
101/2 121/4 76 23
105/8 113/4 87 13
10375
105/8 131/2 71 29
121/8 13 90 10
11625
121/8 143/4 74 26
121/4 131/4 87 13
11750
121/4 15 73 27
143/4 153/4 90 10
14250
143/4 171/2 76 24
161/2 171/2 90 10
16000
161/2 20 75 25
Note: The rig capacity and job specifications will dictate the actual hydraulics available
to the tool.
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The optimal hydraulic horsepower per square in. should be
maintained at the following:
Ream only – 1.3 hhp/in.² for reamer
– 0.5 hhp/in.² for bit or bullnose
HEWD – 1.3 hhp/in.² for reamer
– 1.0 hhp/in.² for bit
Operating Parameters
Effective weight-on-bit (WOB) should be determined
by allowable torque available based on the number
of PDC inserts that actually contact the underreamed
bench area excluding redundant gauge cutters.
As the PDC cutters wear down, the wear flats gener-
ated will continuously absorb more of the applied weight
and ROP will diminish. A gradual increase of weight will
usually be necessary to re-establish the ROP. Generally an
increase in WOB should be implemented before rotary speed,
so the PDC cutters will attain a minimum depth of cut.
For any occurrences of high torque and vibrations,
adjustments in WOB and/or RPM should be considered
to reduce the chances of high impact loading on the
Rhino Reamer and other downhole components.
Maximum Flow Rate through the Rhino Reamer
Tool Series 5750 8000 10000 11750 16000
6125 9250 10375 14250
11625
Max. through flow rate at 75 ft/ 350 734 1147 2249 2249
sec., GPM
Max. through flow rate at 100 466 979 1530 2999 2999
ft/sec., GPM
Available nozzle sizes (ID) 1/32 in. 5 -13 7 - 20 7 - 24 7 - 24 8 - 32
Max. flow rate through each 35 72 141 141 207
nozzle 75 ft/sec., GPM
Max. flow rate through three 105 216 423 423 621
nozzles 75 ft/sec., GPM
Note: The parameters stated above are recommended and actual drilling conditions
may require alternate parameters.
