Research and Development for Bearings

Accomplished scientists with more than 50 years of combined diamond research experience lead the US Synthetic research and development efforts. A separate team of application engineers works directly with customers to develop custom diamond solutions that make the best possible use of the latest technology. These engineers have years of experience with PDC design and working with bit companies. A staff of experienced technicians constantly evaluates and tests new products in the laboratory, so the product is tested and ready for application in the field.

All of these experienced professionals work in state-of-the-art research and testing facilities. This includes a full metallurgical lab, an advanced computer-aided design center, and a sophisticated testing lab. These facilities allow our scientists and engineers to:

• Create and optimize new cutter designs using the latest solid modeling software.
• Model and analyze the thermal and mechanical performance of PDC cutters under simulated drilling conditions using finite element analysis tools.
• Quickly build prototype cutters in a dedicated R&D environment.
• Evaluate cutters using scanning acoustic microscopy (C-SAM), optical and scanning electron microscopy, and metallurgical analysis.
• Monitor and improve cutter performance with abrasion, impact resistance, and vertical turret lathe (VTL) testing.

During wear testing, a high axial load is applied for extended periods of time — from hours to even months. The total diamond wear in the bearing is then measured and converted to a wear rate. Test results are then used to compare the relative wear resistance of different diamond blends, bearing insert geometries, and bearing insert configurations. The results of these wear tests help the US Synthetic Bearings engineering team design the best bearing possible for a given application. Wear test results are also used to predict bearing life in specific applications. The following are examples of wear test results:

During performance testing, US Synthetic’s bearings are tested under constant speed, gradually increasing load until bearing failure occurs. Test parameters and bearing designs can be adjusted to meet the customer’s design, speed, load, and cooling flow rate. The data gathered during this testing is used to generate pressure/velocity (PV) failure curves which define the safe operating envelope for a given bearing. Test results can also be used to predict required cooling flow rate, expected heat generation, and frictional loss in customer applications.

During friction testing, a constant axial load for the duration of the test, gradually increasing speed until the test is complete, is applied to all tests. Test parameters and bearing design can be adjusted to meet every customer’s design, load, and cooling flow rate requirements. The data gathered from these tests is used to generate Stribeck curves, which define the lubrication regimes (boundary, mixed film, and hydrodynamic) present at various speeds. This helps the engineering team at USS Bearings understand and predict the expected friction coefficients associated with the bearings for each given application.

PDCs were first introduced decades ago as a replacement for natural diamonds. These early cutters lacked toughness, were generally limited to the softest drilling applications, and required very specialized bit designs and carefully controlled drilling parameters. Over the years, aggressive innovation and improvements to the process have steadily increased the durability, impact resistance and abrasion resistance of PDCs.

Today’s PDCs are effective in shale, limestone, and sandstone formations. Over time, the PDC-drillable zone will continue to grow and expand (see figure). For example, US Synthetic frequently cuts crystalline rocks for extended periods in a laboratory environment—and is working hard to extend these capabilities to an operating environment.

Today, PDC enhanced bits provide the fastest, most durable and most cost-effective drilling.