Corrosion-Resistant Bearing Assemblies for Cooled Thrust Loads
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Solution Overview
Problem
Subterranean drilling systems face challenges with the operational lifetime of thrust-bearing apparatuses due to corrosion from drilling fluids, which affects the overall performance and longevity of the drilling system.
Innovation Solution
The use of bearing assemblies with corrosion-resistant properties, including support rings and bearing elements coated with refractory metals or ceramics, and sacrificial anodes to prevent galvanic corrosion when exposed to lubrication or cooling fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If bearing elements are exposed to drilling fluid for cooling and lubrication, then the bearing elements are cooled and lubricated, but the metal-solvent catalyst in the bearing elements corrodes
Solution Approach 1:
A corrosion-resistant coating is applied to the bearing elements to act as an intermediary barrier between the metal-solvent catalyst and the corrosive drilling fluid. This coating allows the bearing elements to be cooled and lubricated by the drilling fluid while preventing direct contact between the fluid and the metal catalyst, thereby preventing corrosion.
Solution Approach 2:
The bearing elements are constructed as composite structures with a corrosion-resistant outer layer (such as ceramic or coated metal) over the metal-solvent catalyst core. This composite structure combines the lubricity and strength of metal with the corrosion resistance of ceramic or coated materials, allowing the bearing to withstand both mechanical loads and corrosive environments.
2Strength
If bearing elements use metal-solvent catalyst for structural integrity, then the bearing elements maintain strength, but the catalyst is susceptible to leaching and galvanic corrosion from drilling fluid
Solution Approach 1:
A sacrificial anode made of a more reactive metal (such as zinc or aluminum) is attached to the bearing element. This sacrificial anode corrodes preferentially, protecting the metal-solvent catalyst from galvanic corrosion. The sacrificial anode is replaced periodically when it is consumed, allowing the expensive bearing element to maintain its service life.
Solution Approach 2:
A corrosion-resistant coating is applied to the metal-solvent catalyst to create a protective barrier that prevents direct contact between the catalyst and the corrosive drilling fluid. This coating acts as an intermediary layer that maintains the structural integrity of the bearing while preventing leaching and galvanic corrosion.
3Temperature
If drilling fluid is circulated through the bearing elements for cooling, then the bearing elements are cooled, but the operational lifetime of the thrust-bearing apparatus is reduced due to corrosion
Solution Approach 1:
The bearing elements are constructed as composites with corrosion-resistant materials (such as ceramic coatings or corrosion-resistant alloy layers) combined with the metal-solvent catalyst core. This composite structure allows continuous circulation of drilling fluid for cooling while the corrosion-resistant outer layer protects the internal catalyst from degradation, thereby extending the operational lifetime of the thrust-bearing apparatus.
Solution Approach 2:
A corrosion-resistant coating serves as an intermediary barrier that allows thermal energy to pass through (enabling cooling) while blocking the corrosive drilling fluid from contacting the metal-solvent catalyst. This coating maintains the cooling function while preventing the corrosion that would otherwise reduce the apparatus lifetime.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances the operational lifetime of thrust-bearing apparatuses by protecting them from corrosion, thereby extending the useful life of subterranean drilling systems and maintaining performance.
Implementation Method 1
a corrosion resistant region formed on each bearing element proximate to the bonding region. The corrosion resistant region is configured to prevent corrosion of at least some material covered by the corrosion resistant region
Implementation Method 2
The bearing assembly includes one or more sacrificial anodes that prevent galvanic corrosion of the bearing elements when the bearing assembly comes in contact with lubrication or cooling fluid
Data Source
Figure 1A
Figure 1B~1C
Figure 2A~3B
AI summary
Embodiments disclosed herein relate to bearing assemblies and methods of manufacturing. In an embodiment, a bearing assembly includes a support ring and bearing elements. The bearing elements are mounted to and distributed circumferentially about an axis of the support ring. At least one of the bearing elements includes a polycrystalline diamond table, a substrate bonded to the polycrystalline diamond table, bonding region defined by the substrate and the polycrystalline diamond table, and a corrosion resistant region. The corrosion resistant region includes a corrosion resistant material that covers at least a portion of at least one lateral surface of the bonding region. The corrosion resistant region prevents corrosion of at least some material in the bonding region covered by the corrosion resistant region (e.g., during use). Other embodiments employ one or more sacrificial anodes as an alternative to or in combination with the corrosion resistant region.