Cutter Blocks | Schlumberger

Cutter Blocks

High-performance cutter blocks

Illustration of cutter blocks downhole.

On a reamer, standard PDC cutters are commonly used in many conventional drilling applications. When running reamers with these cutters, different material composition can lead to better performance. Additionally, geometry cutting elements can now be used in reamer cutter blocks to further increase ROP and improve footage. The proven success of geometry cutting elements offers an intelligent solution to challenging reaming applications.

AxeBlock cutter blocks

In medium-to-hard formations with unconfined compressive strengths (UCS) greater than 5,000 psi [35 MPa], conventional cutter blocks lack the necessary stabilization qualities to reduce torque while improving performance during hole-enlargement-while-drilling (HEWD) operations.

The AxeBlock torque-reducing ridged diamond element cutter block improves rock cutting efficiency through a combination of shearing and crushing actions. A unique geometry gives the Axe ridged diamond element a 70% thicker diamond table than that of a conventional cutter, providing increased frontal impact resistance. For operators, this means that the AxeBlock cutter block delivers improved durability and dull condition for maximum ROP throughout HEWD run.

Better toolface control for higher build rates and ROP

The AxeBlock cutter block also features diamond semiround top inserts behind the Axe elements to improve block stability by restricting lateral movement and axial impact. The reduced cutting force required and improved stability translate to less overall torque, minimizing reactive torque fluctuation, and providing better toolface control. This enables better build rates and higher overall ROP, helping maximize production zone exposure and minimize drilling time.

AxeBlock torque-reducing ridged diamond element cutter block.
AxeBlock & StingBlock
Superior performance cutter blocks
StingBlock advanced stabilization conical element cutter block.

StingBlock cutter blocks

Engineered with unique geometry cutting elements, the StingBlock advanced stabilization conical element cutter block is specifically designed to improve footage and ROP in challenging drilling applications that pose a high risk of vibration to the BHA and impact damage to conventional cutter blocks. A staged gauge pad increases stability, and Stinger conical diamond elements are incorporated along the block for enhanced impact resistance. Field tests using this cutter block demonstrated up to a 29% increase in ROP and a 56% increase in footage as compared with benchmark results in the Gulf of Mexico.

Enhanced reamer stability, durability, and improved efficiency

In high-impact and challenging applications with hard and interbedded formations, the StingBlock cutter block provides significant stability due to its stage gauge pad in combination with Stinger elements incorporated along the pad. Stinger elements deliver a higher point load designed to fracture rock more efficiently than a conventional cutter. Additionally, the Stinger element helps disrupt the vibrations that can reduce the energy applied to drilling, thus lowering ROP. All this means longer runs and longer life of the underreamer and BHA.

Improved PDC Cutter Blocks

Improved standard PDC cutters can offer superior resistance and thermal stability, while increasing impact resistance by more than 20%. That is the reason why we offer cutter blocks equipped with both conventional and premium cutters—including cutter blocks with FireStorm wear-resistant high-impact PDC cutter technology, which is ideal for medium-strength formations with low vibration risk.

Cutter blocks with improved PDC cutters stay sharp longer, enabling more footage to be drilled at faster ROP and providing maximum performance in a range of applications, including highly abrasive, interbedded, and difficult-to-drill formations. Premium PDC cutters developed by Smith Bits, a Schlumberger company, improve thermal stability in hard, abrasive formations and increase wear resistance.


PDC cutter block.
Cement cleanup blocks.

Cement cleanout blocks

Cement cleanout blocks can be run in tandem with a standard Rhino XS hydraulically expandable reamer, enabling removal of the cement sheath that forms in the casing ID when drilling out the shoe track. Flow through the reamer activates the cutter blocks.

Typically run in tandem with a Rhino integrated borehole enlargement system, cement cleanout blocks assist in clearing cement from casing when drilling out the shoe track.

Cement cleanout blocks increase stability when drilling new formation after the shoe track has been drilled out. In addition, they reduce the risk of stuck BHAs by providing dependable cutter block retraction.

Schlumberger offers cement cleanout blocks in several sizes and configurations to accommodate a wide range of casing IDs.

Stabilizer blocks

The Rhino system stabilizer uses three abrasion-resistant stabilizer blocks. When run above the reamer, the stabilizer provides concentric, stable points of contact in the enlarged hole section, increasing lateral support. Tungsten carbide hardfacing and diamond-enhanced inserts are available to provide additional wear resistance.

The Rhino system stabilizer can be used with the Rhino XS reamer to reduce drillstring vibration in borehole enlargement operations.

The stabilizer reduces drillstring vibration, which is increasingly important as well profiles and individual components in modern drillstrings become more complex. Vibration affects the life of downhole tools and surface equipment, slows drilling, and results in irregular boreholes.

Stabilizer block.
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