What is stepped pDC drill bit

Definition

 The stepped PDC drill bit is an innovatively designed precision PDC cutter. It is not like traditional drill bits, where the PDC cutting teeth on the blade are all in the same plane. In contrast, stepped drill bits are designed with PDC cutting teeth of different heights on the blade wings to form a “stepped” arrangement.

Structural features

 The core of a step shaped pdc cutters is the arrangement of its PDC cutting teeth.

 These cutting teeth are gradually raised from the center of the drill bit to the periphery and arranged in a stepped manner.

 This design allows each cutting tooth to contact the formation at a better angle and with a smaller cutting area, thereby dispersing cutting forces and improving drilling efficiency.

Unique advantages

• Higher rock breaking efficiency: The design of multiple layers of cutting edges allows it to cut more rock per unit time, thereby increasing drilling speed.
•  Longer drill bit life: Stress dispersion mechanism effectively reduces the wear rate of individual cutting teeth and extends the overall drill bit life.
•  Better impact resistance: The stepped structure can absorb and disperse impact loads to a certain extent, reducing the risk of tooth chipping. This is especially important for working conditions with complex formations and large impacts.
•  Optimize chip removal: The stepped shape helps form smaller chips and optimizes chip removal, reducing the chance of drill bit mud bales.

 

Application scenarios

• Medium-hard to hard formations: For medium-hard formations such as shale and sandstone, the efficient rock-breaking ability of the stepped bit can significantly improve the drilling efficiency.
• Complex formation: In the formation with interlayer and strong abrasiveness, its excellent impact resistance and wear resistance can ensure the stable operation of the drill bit.
• Excavation of directional and horizontal wells: In directional and horizontal well operations that require higher drilling efficiency and longer service life, the stepped PDC bit is also a very good choice.

How to choose the right stepped pDC bit

Formation characteristics

• Soft formation: If it is a soft formation, it may pay more attention to the drilling speed, and it may be more appropriate to choose a bit with a larger cutting angle and a thinner PDC layer.
• Medium-hard formation: For medium-hard formation, it is necessary to balance the drilling speed and the life of the drill bit, and select the drill bit with good comprehensive performance.
• Hard or abrasive formation: In this case, wear resistance and impact resistance are the primary considerations. PDC layer thickness, PDC particle size and PDC content are very important.

Tool design

• Number and height of steps: Different number and height of steps will affect cutting efficiency and drill stability.
• Generally speaking, the more and more fine steps, the more stable the cutting, but the depth of rock breaking may be limited; the ladder is tall, the depth of rock breaking is deep, but the impact may be large.
• PDC layer thickness: The thickness is directly related to the wear resistance of the drill bit. A thicker PDC layer usually means longer life, but may also bring higher costs.
• Cutting angle: Different cutting angles are suitable for formations with different hardness. The acute angle cutting efficiency is high, but it is easy to wear; the obtuse angle is wear-resistant, but the efficiency is relatively low.

Application materials

• PDC sintering technology: high-quality PDC cutting teeth, the uniformity of diamond particles and sintering strength directly affect the performance of the drill bit.
• Matrix material: usually hard alloy or steel body, the strength and toughness of the matrix material determines the overall impact resistance and connection strength of the drill bit.

Related certification standards

API Monogram certification

API Monogram certification is the highest embodiment of API standard. If a PDC drill bit manufacturer obtains API Monogram certification, it means that its products conform to API related specifications and its quality management system has passed the strict examination of API.

ISO 9001 certification

ISO 9001 certification is the globally recognized standard for quality management systems.

For PDC bit manufacturers: ISO 9001 certification shows that the company has reached the international level in product quality control, customer satisfaction, continuous improvement, etc., which helps to enhance the corporate image and market competitiveness.

How to extend the life of the drill bit

• Reasonable operation parameters: strictly control the WOB and speed according to the formation conditions. Excessive weight on bit or rotational speed will accelerate the wear of the drill bit.
• Timely inspection and maintenance: Every time you trip, carefully check the wear of the drill bit. If a slight tooth break or abnormal wear is found, analyze the cause in time and adjust the operation.
• Maintain good circulation: Adequate mud circulation can not only effectively cool the drill bit, but also discharge rock cuttings in time, reduce the mud bag and repeated cutting of the drill bit, which is particularly important for PDC drill bit.
• Avoid severe impact: try to avoid severe impact in the drilling process, especially in the formation interface or encounter hard interlayer, to slowly adjust the parameters.

FAQ

Are stepped pdc drills suitable for all terrain situations?

The stepped PDC bit is not suitable for all terrain conditions. Although it performs well in some specific formations, its design characteristics also determine that it cannot adapt to all terrain. For example, in soft formations where mud packs are easily formed, ridge shaped trade pdc cutters will perform better.

Is the stepped PDC bit more expensive than the traditional PDC bit?

It is usually slightly more expensive because its design and manufacturing process are more complicated. But in the long run, considering its higher drilling efficiency and longer service life, the overall drilling cost may be lower.

How to determine whether the drill needs to be replaced?

Mainly depends on the degree of wear of cutting teeth, whether there is a large area of chipping teeth, drilling speed is significantly reduced. Experienced masters can usually judge by hand feeling and drilling speed changes. If the visible PDC layer has been severely worn, it must be replaced.