Application Introduction of 8 1/2-inch PDC Drill Bit

1. Product Overview

The 8 1/2-inch PDC (Polycrystalline Diamond Compact) drill bit is a core drilling tool widely used in the fields of oil and gas exploration, geological prospecting, and mining. With a diameter of 215.9mm, it is well-suited for most medium-deep drilling operations (ranging from 2000m to 6000m). Leveraging the ultra-high hardness of polycrystalline diamond compacts and optimized bit structure design, it has become an efficient drilling solution that replaces traditional roller cone bits, significantly improving drilling efficiency and reducing operational costs.

2. Core Material Composition

The performance of the 8 1/2-inch PDC drill bit is largely determined by its high-quality material composition, which mainly includes three key parts:

2.1 PDC Cutters

The cutting teeth of the drill bit are made of high-quality polycrystalline diamond compacts. These compacts are sintered from artificial diamond micro-powder under high temperature and high pressure. The diamond layer of the PDC cutters has a hardness of over HV10000, and its wear resistance is 50 to 100 times that of cemented carbide. This enables the drill bit to maintain excellent cutting performance even in abrasive formations.

2.2 Tungsten Carbide Matrix

The matrix that supports the PDC cutters is made of high-strength tungsten carbide-based cemented carbide. This material combines outstanding impact resistance and wear resistance, which can effectively support the PDC cutters to work stably in complex formations. It avoids matrix cracking caused by stratum impact during the drilling process, ensuring the integrity and reliability of the drill bit structure.

2.3 Bit Body

The main body of the drill bit is forged from 42CrMo alloy steel. After quenching and tempering heat treatment, its tensile strength reaches more than 1000MPa. This high-strength bit body can withstand the high drilling pressure (up to 350kN) and high rotational speed (up to 200rpm) during drilling operations, ensuring structural stability and long-term service life of the drill bit.

3. Performance Advantages

Derived from its advanced material composition, the 8 1/2-inch PDC drill bit exhibits significant performance advantages compared to traditional drilling tools:

• Ultra-high Drilling Efficiency: The high hardness of PDC cutters allows the drill bit to achieve a drilling rate (ROP) that is 30% to 100% higher than that of roller cone bits in conventional formations such as sandstone and limestone. This greatly shortens the drilling cycle.
• Long Service Life: The wear-resistant materials reduce the loss of cutting teeth. The footage of a single 8 1/2-inch PDC drill bit can reach 2 to 5 times that of a roller cone bit, significantly reducing the number of tripping operations and lowering the overall drilling cost.
• Stable Drilling Trajectory: The synergy between the rigid material and optimized structure endows the drill bit with excellent directional drilling capabilities. It is suitable for vertical wells, horizontal wells, and extended-reach wells, ensuring accurate control of the drilling path.

4. Main Application Scenarios

Due to its excellent performance, the 8 1/2-inch PDC drill bit is widely applied in various fields:

4.1 Oil and Gas Drilling

As the main drill bit for medium-deep formations, it is extensively used in the drilling of deviated sections, horizontal sections, and tangent sections in composite formations such as sandstone, mudstone, and limestone. It is particularly suitable for the efficient development of unconventional oil and gas resources such as shale gas and tight oil. In shale gas horizontal well drilling, it can maintain high drilling efficiency for a long time, effectively reducing the cost of shale gas development.

4.2 Geological Exploration Drilling

In the field of geological exploration, this drill bit is used for coring drilling in mineral resource exploration and hydrogeological surveys. Its high-precision cutting characteristics can effectively protect the integrity of the rock core, ensuring the accuracy of exploration data. This is crucial for determining the distribution and reserves of mineral resources.

4.3 Mining Drilling

In mining operations, the 8 1/2-inch PDC drill bit is suitable for drilling ventilation wells, drainage wells, and blast holes in coal mines, metal mines, and other mining areas. In hard rock formations, it shows excellent rock-breaking efficiency, meeting the high-efficiency operation needs of large-scale mining. It can adapt to the harsh working environment of mines and maintain stable performance.

4.4 Other Special Fields

It also has applications in special fields such as geothermal well drilling and coalbed methane development. With its temperature resistance (able to withstand temperatures above 200℃) and corrosion resistance, it can adapt to the harsh working conditions of special formations. For example, in geothermal well drilling, it can resist the high-temperature environment underground and ensure the smooth progress of geothermal resource development.