HALLIBURTON SECURITY DBS

The FM3000 series bit was developed using a new cutter/rock interaction model based on a better understanding of cutter wear. Previous wear models estimated only the wear flat without considering the orientation of the wear flat, the actual diamond thickness, the interface geometry of diamond layer and carbide, or abrasive resistance. Cutter wear is analyzed in three dimensions, and all factors, including those overlooked by the previous model, are taken into account, including a Transition Drilling Model that simulates a fixed cutter bit drilling through a change in rock strength such as shale to sandstone. Then, specific bit features such as profile shape, blade count, cutter density, cutter back rake, and impact arrest or location can be manipulated to improve the bit's performance in drilling transitional formations.

Of the three forces acting on a bit - axial force, lateral force and a bending moment - it has long been recognized that balancing the lateral force is important to preventing whirl. Previous concepts of PDC bit force balancing assumed that once lateral force was balanced, the bit bending moment also was balanced. However, further study found that bit bending moment contributes not only to bit whirl, but also to bit tilt, which has a significant effect on directional control. Therefore, balancing the bending moment is equally important as balancing lateral force - and such bits are considered "globally force-balanced."

The concept of energy balanced bits is based on the fact that the amount of formation removed by each cutter on a bit is different, and as a result, the force acting on each cutter also differs. In order to avoid overloading individual cutters and blades, it is necessary to control these load distributions. Thus, designing a "torque and drag balanced" PDC bit involves analyzing the distribution of work and forces on a cutting structure with the aim of controlling force distribution over blades and cutters. As with force balancing, a specific set of design criteria has been developed. By controlling the force distribution over blades and cutters, impact damage and uneven wear is reduced while penetration rate (ROP) is improved.

Until recently, efforts to use PDC bits to drill the Travis Peak produced only marginal economic improvement. To ensure extended bit life and provide a more robust cutting structure, an FM3000 series with Z3 and Rhino backup cutters was recommended. In addition to the cutters, the Hard Rock design features continuous spiraling blades through the gage pad for optimized distribution of lateral forces, and single set cutting structure for increased aggressiveness.

An FM3000 series bit drilled 1,681 ft (513 m) of the Travis Peak formation at an average rate of penetration of more than 40 ft/hr; outperforming all offsets in both footage drilled and ROP. This outstanding footage performance eliminated additional bit runs and reduced cost per foot to create savings of $14,178.

These new FM3000 bits have revolutionized the way such formations are drilled, saving operators thousands of dollars per well. Drilling days have been cut dramatically - by up to 60% in certain fields in East Texas.

HUGHES CHRISTENSEN

Hughes Christensen (HCC) has introduced the new EZ Case casing bit system (EZC) to aid in getting casing to existing total depth (TD), drilling through trouble zones, controlling hole instability and lost circulation zones. The system can be used in one continuous operation or after the hole has been drilled conventionally. EZC's full polycrystalline diamond cutting (PDC) structure allows it to drill and/or ream farther in harder, more abrasive formations than was previously possible. Core technology includes:

• PDC drillable construction
Special alloy construction allows either a steel tooth or a specialized PDC to drill out the casing bit along with the shoe track.
• Advanced cutting structure
A full alloy head allows premium Genesis cutting elements to be attached to the blades, ensuring a robust cutting structure capable of efficient reaming and drilling in a broad range of formations.
• Engineered nozzle placement
Drillable nozzles provide flexibility in achieving higher hydraulic horsepower, which maximizes cuttings removal and PDC cutter cooling.
• Secondary bypass port
A bypass port allows normal circulation or cementing to continue in the event of nozzle plugging.
Proven EZC field performance

EZC recently delivered a step-change in performance drilling a trouble zone for a major independent in the Gulf of Mexico. The objective was to drill down 7,842 ft (2,391 m) of 95/8-in. casing through the problem zone. To achieve these goals, a 121/4-in. EZC304 was selected in an attempt to improve rate of penetration (ROP), which averaged 7ft/hr (2.1 m/hr), and durability 269 ft (82 m), achieved with a competitor's system on the previous well.

RBI-GEARHART

In most bi-center applications polycrystalline diamond compact (PDC) cutters are preferred. However, in some cases PDC will not stand up to all formations. RBI-Gearhart's roller cone bi-center will meet those situations requiring tough tangsten carbide insert (TCI) drilling.

The uniqueness of this roller cone bi-center is that it can easily be re-dressed in the field. Each cutter assembly is machined with tapered locking grooves that seat in matching grooves in the body. Once in place, the segment is retained in the locked position by six tapered wedges that are bolted in. While six wedges are required to seat the segment securely, any one of these six is sufficient to hold the segment in place.

Each roller cone bi-center bit is manufactured with a durable sealed-motor bearing or sealed-motor roller bearing system, utilizing proprietary HNBR seals to ensure each run meets expectations. To ensure the drilled diameter maintains its gage, each cutter incorporates the patented Reaming Gage for maintaining bore gage from start to finish. For stability the bi-center incorporates a lug pad system, containing TCI inserts ensuring ultimate stabilization.

REEDHYCALOG

Polycrystalline diamond compact (PDC) bits
TReX thermostable PDC (t-PDC) technology, designed, developed and manufactured in-house, utilizes a thermostable layer on the leading edge of the polycrystalline diamond. This layer is 400% more abrasion-resistant than premium polycrystalline diamond, but more important it is 200% more heat-tolerant.
At temperatures in excess of 1,380?F (750?C), polycrystalline diamond reverts to graphite. Because the leading edge of TReX cutters can withstand more than twice this temperature, TReX t-PDC cutter-equipped bits can drill even the hardest, most abrasive formations. Laboratory testing demonstrates this and is backed up by numerous successes all over the world in the toughest applications.

Several manufacturers' latest generation cutter technologies have been run against TReX-equipped bits; none were competitive. In wells drilled to greater then 8,000 ft (2,439 m) in the past 2 years only 10 runs have drilled shoe-to-total depth. All were TReX t-PDC cutter-equipped bits. The average footage of the top three performing bit companies again shows the dominance of TReX-equipped bits. The benefits of thermostability, in terms of both footage drilled and rate of penetration (ROP), are evident in many such applications where abrasive formations are encountered.

Roller cone bits

TuffCutter roller cone drill bits from ReedHycalog are setting new standards of performance. Manufactured utilizing the patented and proprietary powder forging process, the bits feature the most consistent, wear-resistant tungsten carbide possible. The result is a durable, aggressive cutting structure that remains sharper, longer. Unique to TuffCutter bits are features like Bilt-In multi-modal hardmetal that provides superior gauge and inner row cutting durability; FullGage, 100% cutter heel coverage for superior gauge protection; and TuffJacket, erosion resistant hardmetal coverage on 100% of the cone shell.

These bits have superior performance in directional, straight-hole motor and conventional rotary drilling in applications as diverse as Gulf of Mexico, Venezuela, Russia and South/West Texas. Currently, the bits are available in 77/8-in. through 83/4-in. API standard diameters. New 121/4-in. bits are now undergoing field tests.

Case study: Russia and Gulf of Mexico

Originally developed for soft formation drilling (IADC 117 -137) TuffCutter products have competitively drilled multiple IADC ranges up to IADC 417 formations types. For example, in Russia, the bits successfully drilled a 117 - 417 application using 81/2-in. TC11 bits. Comparing 81/2-in. TC11 to western manufactured 117 tooth and 417 insert bits, TuffCutter bits drilled 27% more footage on average with no bearing failures, compared to 81% bearing failure rates in the competitor products.

The key to the bit's success is durability. In a comparative study conducted for the Gulf of Mexico, bits sized 77/8 in. through 83/4-in. were compared with competitor IADC 117 products. When comparing tooth wear and bearing failure rates, footage drilled and ROP, TuffCutter bits came out on top. The bits are manufactured from the patented powder forging process combined with ReedHycalog advanced bearing designs and are setting new limits in soft formation drilling performance.

For more details contact your local ReedHycalog sales representative or visit www.ReedHycalog.com/TReX.

SMITH BITS

Smith Bits has a single-minded focus on providing products that help drillers drill their wells at the lowest possible cost per foot. This objective is achieved by integration of a team of experienced design and manufacturing engineers with a field service organization that aggressively works with drilling personnel around the world to ensure optimal performance in all drilling applications.

The company has an ongoing commitment to the development of materials that enhance the performance of Smith Tool roller cone and GeoDiamond polycrystalline diamond compact (PDC) products. Concentration on research and development (R&D) has yielded consistent advances in product performance and reestablished material standards for the entire industry.

The development of tungsten carbide materials formulated to improve performance in specific applications is noteworthy. Work with coarse-grade carbides has resulted in a wide range of proprietary carbide grades that combat heat checking and insert breakage that occurs as a result of thermal damage. The various grades of coarse-grain tungsten carbide particles provide extreme toughness and impact resistance, while withstanding high operating temperatures without thermal damage.

Materials research also extends to the evolution of hard facing technologies for the protection of roller cone bits and milled tooth bits. Smith materials scientists have a goal to create unique hard facing formulations and deposition techniques that increase the wear resistance and durability of existing hard facing materials. The hard facing material, designated M1C2, is a product of these materials improvement objectives. Using industry-standard wear tests, M1C2 achieves a 41% improvement in wear resistance relative to the previous hard facing. Smith Bits' premium Xplorer Expanded XR+ product line demonstrates the worth of M1C2 through new performance records set around the world.

GeoDiamond, too, invests heavily in materials research and development. Innovative high operating temperature (HOT) cutters provide a significant increase in cutter wear resistance and are very cost-effective in applications where cutter wear rates are excessive. The use of HOT cutters enables a bit to remain sharp longer and, therefore, maintain a high rate of penetration (ROP) for longer periods than those using conventional cutters.

These cutters also excel at higher rotational speeds, especially in clastic drilling. Improvements in wear resistance are achieved through a proprietary process that matches thermal properties of a cutter to expectations of temperature to be generated during drilling. HOT cutter diamond tables are typically ±0.012 in. thick, a thickness that is greater than most other available cutters. Because of this high diamond volume, HOT cutters exhibit exceptional wear resistance while retaining excellent impact characteristics. When applying the industry-standard Granite Log Test, a .63-in. HOT cutter showed a wear improvement of 125% compared to conventional premium cutters.

GeoDiamond's patented GHI (grit hot-pressed insert) has contributed dramatically to improving the performance of impregnated drill bits. GHI is impregnated diamond "grit" (natural, synthetic or blended) that is subjected to a fast, high-pressure sintering process. The result of this process is an impregnated diamond insert that can be arrayed in a variety of configurations on the body of the bit. GHI material developments, in combination with significant evolution in impregnated bit designs, enable the bits to drill at higher rotational speed and higher ROP for longer periods of time. The combination of increased speed and footage means lower cost per foot for the customer.

VAREL INTERNATIONAL, INC.

In early 2004, Varel International began utilizing Advanced Force Balancing in all of its fixed cutter products. While force balancing has been used to design polycrystalline diamond compact (PDC) bits since the mid 1980s, Advanced Force Balancing is an evolutionary step that significantly improves rate of penetration (ROP), dull bit condition and deviation control over conventionally balanced PDC bits. The theory of force balancing is to minimize the resultant side force by strategic adjustment of individual cutter side rake and back rake. As PDC bits drill, each cutter exerts a force on the bit in a predictable direction and amount. If all of the forces exerted by all of the cutters are summed, there is a resultant force in some radial direction around the face of the bit. Advanced Force Balancing is made possible by Varel's proprietary design software SPOT 4D. This design software allows the company's design engineers to force balance PDC bits over the widest range of ROPs and revolutions per minute (RPMs) possible. The result is a bit that is stable under practically all drilling conditions. The benefit to customers is a bit that drills faster, lasts longer and is more directionally stable than ever before. Recent results from Canada support these claims.

Field study

A field study measuring the difference between conventional force balancing and Varel's Advanced Force Balancing was recently conducted in eight oil fields in Western Canada. The study compared 18 Varel bits runs with conventional force balancing and 14 recent competitor bit runs against 11 Varel bit runs using Advanced Force Balancing. With the technology, the average number of meters drilled increased 52% while ROP increased 41% and dull condition improved an average of two points. Drillers also reported that they could push the bits harder in zones known for deviation problems without increasing deviation.

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