ONYX 360Rolling PDC cutter

Applications

■ Drilling conditions that cause and accelerate PDC cutter wear

■ Abrasive environments

Benefits

■ Extends bit durability ■ Increases run footage and average ROP ■ Improves thermal dissipation to extend

cutter life

Features

■ 360° revolution capability allows cutter to stay sharper longer

■ Number and placement of cutters can be customized to maximize durability in bit cutting structure’s high-wear areas

■ Can be integrated into any PDC bit cutting structure without changing cutter size

■ Available in 13-mm and 16-mm sizes

ONYX 360 Rolling PDC Cutter

The next revolution in PDC cutter durabilityThe ONYX 360* rolling PDC cutter substantially increases PDC bit durability by revolving 360°. Strategically positioned in the highest wear areas of a bit’s cutting structure, the rolling cutter’s entire diamond edge is used to shear the formation. The cutter’s rotating action allows the diamond edge to stay sharper longer, extending ONYX 360 cutter life far beyond that of premium fixed cutters.

When compared with bits that only have fixed cutters, PDC bits that included ONYX 360 rolling cutters demonstrated run length increases of up to 57%.

Microscopic inspection of PDC cutters enabled analysis of diamond edge wear after running cutters on test formations.

Revolving edge advances PDC cutter durability

Results

Quantified ONYX 360 rolling cutter’s effectiveness and durability:

■ Increased cutter durability

■ Increased ROP up to 44%

■ Extended run lengths up to 57%

Evaluation

Conduct extensive testing: ■ Measure durability

increases of rolling cutter

■ Assess strength of dynamic PDC cutter system

■ Confirm 360° rotation of cutter

Simulation

Undertake cutter analysis using IDEAS* integrated drillbit design platform:

■ Identify which fixed cutters to replace

■ Optimize orientation and placement of rolling cutters in PDC bit blade

Development

Explore new cutter designs: ■ Determine feasibility

of a more robust cutter system

■ Investigate the functionality of dynamic cutters

■ Analyze cutting forces that generate rotation

Challenge

Improve PDC cutter durability:

■ Extend cutter life in high-wear applications

■ Employ the cutter’s entire diamond edge to minimize wear

■ Sustain a bit’s initial high ROP

The introduction of PDC cutters in the 1970s permanently changed well construction programs. Now, they are readily accepted as the workhorse cutting element of the drilling industry, accounting for over 80% of the total footage drilled in oil and gas wells worldwide.

Despite their dominance, fixed PDC cutters have an inherent limitation: Most of the cutter’s edge is fixed into the bit blade, limiting contact with the formation. Accordingly, more than 60% of the cutter’s circumferential edge goes unused during a bit run.

Cutter’s diamond edge goes largely unused

Cutter used 10 to 40%

Cutter unused 60 to 90%Unused cutter

Cutting edge

Challenge

More than 60% of a fixed PDC cutter’s diamond edge goes unused (green) during

a bit run, leaving only 10 to 40% of the edge (red) to cut the formation.

Fixed cutter design limits cutter potentialThe part of a fixed cutter’s edge that engages the formation is subjected to mechanical and thermal effects that cause wear and chipping. This concentrated degradation on a small percentage of the cutter’s edge results in loss of shearing efficiency, slowing the rate of penetration. In addition, bit durability is substantially reduced, resulting in shorter bit runs.

Using a rolling PDC cutter would increase durability by ensuring that the part of the cutter’s edge making contact with the formation is continually refreshed to stay sharper longer. In addition, the rotating action would improve thermal dissipation preventing concentrated heat buildup.

A dull photo (left) illustrates the degree of wear a fixed cutter incurs and where it is most concentrated.Finite element analysis (FEA) modeling software depicts the amount of frictional heat generated by a fixed cutter (right), with concentrated heat buildup in red.

+3.710e+02+3.568e+02+3.425e+02+3.282e+02+3.140e+02+2.998e+02+2.855e+02+2.712e+02+2.570e+02+2.428e+02+2.285e+02+2.142e+02+2.000e+02

NT11

Fixed PDC Cutter

In an analysis of over 45,000 PDC bit runs, 60% of dull grade characteristics were identified as worn and chipped cutters, conditions that shorten cutter life and result in lower ROP and premature bit trips.

Challenge

Inventive design increases cutter lifeIntegrating a rolling cutter into a PDC bit’s cutting structure required a novel and robust design. Smith Bits R&D engineers developed a cutter system composed of a housing that is brazed into the bit blade, and within which a sleeve encloses and completely secures the cutter while allowing it to rotate.

The ONYX 360 cutter’s shaft is fully contained within an

integrated housing to ensure continuous rotation and cutter

retention during drilling.

The rolling cutter’s orientation in the bit blade, relative to its contact

with the formation and the bit’s drilling force, drives efficient

rotation of the cutter.

Durability analysis includes mounting PDC cutters in a test fixture and running them on formation samples.

Development

Cutter durability advances to a new levelTo compare the new rolling cutter with a premium PDC fixed cutter, durability tests were conducted in which both cutters were mounted on test fixtures to engage a granite test formation with an unconfined compressive strength of 30,000 psi.

To maintain a constant ROP, the vertical force required for premium fixed cutters had to be continually increased from 100 lbf to over 1,200 lbf to compensate for their wear rate. ONYX 360 rolling cutters required substantially less force, confirming that the cutter was remaining sharp for the complete test interval.

When compared with premium fixed cutters, ONYX 360 cutters required far less additional loading force as drilling progressed, indicating improved cutting durability.

Aver

age

verti

cal f

orce

, lbf

1,400

1,200

1,000

800

600

400

200

0

Number of cutting passes

ONYX 360 cuttersPremium fixed cutters

0 100 200 300 400 500 600 700

Development

Comprehensive evaluation validates rolling concept

The wear that fixed cutters incur is concentrated on a small percentage of the cutter’s entire diamond edge. As a result, after 90 passes on a test formation, premium fixed cutters developed extreme wear flats. Because 100% of the ONYX 360 rolling cutter’s diamond edge engaged the test formation, wear was evenly distributed and resulted in virtually no wear after 300 passes and very little wear after 540 passes.

Rock cutting passes

Prem

ium

fixe

d cu

tter

ONYX

360

cut

ter

0 50 100 150 200 250 300 350 400 450 500 550 600

120

90

300 480 540

Development

IDEAS platform determines cutter integrationUpon completion of laboratory testing, bit design engineers entered the ONYX 360 cutter’s design in the IDEAS platform. This step enabled engineers to integrate cutters into the PDC bit’s cutting structure. Integration was determined by examining the effect different geometric orientations had on three cutter characteristics: durability, appropriate balance of driving force, and aggressiveness.

The IDEAS drillbit design platform enabled engineers to optimize placement of the rolling cutters on bit blades to ensure reliable cutter rotation.

Simulation

Drilling force analysis optimizes cutter placement

Using IDEAS design platform enables fixed cutters, in the highest wear areas of a PDC bit’s cutting structure, to be selectively replaced with ONYX 360 rolling cutters.

In abrasive formations, the bit’s shoulder area (between the center of the cutting structure and gauge) typically experiences the greatest amount of cutter wear. The ability IDEAS drillbit design platform has to predict the degree and precise location of this wear makes it an essential design tool.

ONYX 360 cuttersPremium fixed cutters

Distance from bit center, in

0 0.5 1 1.5 2 2.5 3 3.5

Wea

r Fla

t Are

a, in

2

0.14

0.12

0.10

0.08

0.06

0.04

0.02

0

Distance from bit center, in

Wear Flat Area After 150 hours

0 0.5 1 1.5 2 2.5 3 3.5

High wear area

By analyzing the highest wear areas of cutting structures on PDC bits with only fixed cutters, design engineers were able to identify where ONYX 360 cutters should be positioned on bit blades to optimize cutter life and bit durability.

Simulation

Rotating action greatly extends cutter lifeFor the most direct comparison, ONYX 360 rolling cutters were fitted to a PDC bit blade next to premium fixed cutters. After drilling an 1,800-ft horizontal section in abrasive sandstone, both cutter types were compared: The dull condition of neighboring fixed cutters graded poor, while the rolling cutters were in excellent condition. This resulting low and uniform wear provided evidence that rotation had taken place, and using ONYX 360 rolling cutters in the shoulder area would increase drillbit durability.

ONYX 360 cutters (A-D) showed virtually no sign of wear (dull grade T0) compared with the adjacent fixed cutters (dull grade T1 and T2).

c d

a bBA

DC

Evaluation

Dull bit with ONYX 360 cutters after drilling 1,800 ft through abrasive sandstone in 160 hours.

Evaluation

B

A

D

C

Case Study

The operator deployed bits with 16-mm rolling cutters to increase bit run length and ROP compared with 13-mm rolling-cutter and fixed-cutter bits, Oklahoma

Challenge

Improve footage and ROP per bit while drilling horizontal laterals in Oklahoma’s abrasive Colony Wash play.

Solution

Deploy bits fitted with 16-mm ONYX 360 rolling PDC cutters to maintain an efficient cutting structure for improved run length and ROP.

Results

Increased footage and ROP across three wells in the same play. Drilled the highest ROP for a Colony Wash lateral using 16-mm rolling PDC cutter bits.

Chesapeake Energy Improves Footage per Bit and ROP in Abrasive Formation with ONYX 360 Rolling PDC Cutters

Results

Results

Since 2009, Chesapeake has deployed various fixed and rolling cutter types in the Colony Wash play. Upon introducing 16-mm ONYX 360 cutters in 2015, the operator increased both footage and ROP (data averaged across 6 runs using the new cutters).

20132012 2014 2015

2,500

2,000

1,500

1,000

500

0

■ Fixed cutters■ 13-mm ONYX 360 cutters■ 16-mm ONYX 360 cutters

Average Footage, ft

201420132012 2015

25

20

15

10

5

0

Average ROP, ft/hr

Case Study

The operator gained an additional 1,500 ft of bit life in the highly abrasive Hosston Sands and Cotton Valley Lime with 16-mm ONYX 360 rolling PDC cutters

Challenge

Increase run footage by 1,500 ft—to at least 9,500-ft MD—with one bit to enable running a more aggressive bit to complete the lower intermediate section for improved overall ROP.

Solution

Use the IDEAS platform to determine the optimal bit design for the application; deploy 16-mm ONYX 360 rolling PDC cutters for improved wear and extended cutter life.

Results

Increased run footage to reduce an unnecessary bit trip in the intermediate section with increased overall ROP and less rig NPT associated with drillout (DO) runs.

Chesapeake Energy Increases Run Footage and Reduces NPT in Intermediate Section, Onshore Louisiana

Results

“I think we have some significant opportunity to make this intermediate hole section a consistent two-bit section. Depending on what we can do with ROP, this may develop into a one-bit hole section like we aspire to in most of our other plays.”

Greg Bruton Drilling Advisor Chesapeake Energy

Results

Offset Pad Well 1

Fixed Cutter DO Run

Offset Pad Well 2

Fixed Cutter DO Run

Offset Pad Well 3

Fixed Cutter DO Run

ONYX 360 Cutters Well A DO run

ONYX 360 Cutters Well B DO run

ONYX 360 Cutters Well C DO run

69.0 h

85.0 ft/h

5,864 ft

101.5 h

60.0 ft/h6,095

ft

62.5 h

71.5 ft/h

4,496 ft

166.5 h

48.5 ft/h

8,075 ft

166.5 h

47.4 ft/h

7,892 ft 166.0

h

48.6 ft/h

8,062 ft

An 83/4-in bit fitted with ONYX 360 cutters outperformed conventional PDC bits with similar drilling parameters in the same formation.

Drilling Parameters

ONYX 360 Cutter DO Section

Lower Intermediate Section

Depth in, ft 1,850 9,500

Depth out, ft 9,800–10,000 11,000+

Section length, ft 7,800–8,000 1,800

Drilling time, h 150–170 (on bottom)

30–40

Dull grade 2-3-BT-S-XXX-IN-WT-BHA

2-2-WT-S-XXX-IN-WT-TD

Water-base mud, lbm/galUS

9.0–10.5 9.0–10.5

ROP, ft/h 45–55 30–40

Case Study

ONYX 360 Cutter Increases PDC Bit’s Run Footage 57% in Granite Wash Formation, Texas

Results

Bit with rolling cutters drills 1,562 ft of a 5,113-ft, 61⁄8-in lateral gas well section at 25 ft/h

Challenge

Drill 61⁄8-in lateral gas well sections of at least 5,000 ft through abrasive reservoir sand, which caused some fixed-cutter-only PDC bits to be replaced after drilling less than 65 ft.

Solution

Run a 61⁄8-in MSiR613 PDC bit fitted with seven ONYX 360 rolling PDC cutters positioned in the areas of the bit’s cutting structure with the highest predicted wear.

Results

Drilled 1,562 ft of a 5,113-ft, 61⁄8-in lateral gas well section at 25 ft/h using a bit with rolling cutters, which when compared with the best drilling performances in the same formation by fixed-cutter-only bits, increased ROP 44% and footage drilled 57%.

The 61/8-in MSiR613 PDC bit drilled a 1,562 ft lateral in the hard and abrasive Granite Wash formation. When compared with the best performance by a bit with only fixed cutters drilling the same lateral well, the PDC bit with ONYX 360 rolling cutters reported an average ROP increase of 44% and a run length increase of 57%.

Depth in ONYX 360 bit Smith Bits PDC bits Other bits ROP

Dept

h, ft

10,000

11,000

12,000

13,000

14,000

15,000

16,000

30

25

20

15

10

5

0

ROP,

ft/h

1,562

540

996 63

495 115

675

667

MSiR613 MSi613 MSi713 MSi613 Other bit MSi611 Other bit Other bit

10

7 6

25

13

1514

17

Results

ONYX 360Rolling PDC cutter

Find out more about ONYX 360 rolling PDC cutter technology atslb.com/ONYX360

*Mark of SchlumbergerOther company, product, and service names are the properties of their respective owners.

Copyright © 2015 Schlumberger. All rights reserved. 15-BT-27703