Fixed Cutter Drill Bit Composition for Strength and Erosion Resistance
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Solution Overview
Problem
Conventional fixed cutter drill bits exhibit low Transverse Rupture Strength (TRS), moderate to poor erosion resistance, and limited Charpy Impact Toughness, leading to reduced durability and increased wear during drilling operations, necessitating frequent bit changes and increased drilling costs.
Innovation Solution
A powdered metal matrix mixture comprising specific size distributions of tungsten carbide (WC) particles and metal alloy particles is infiltrated with a metal alloy to form a bit body, enhancing mechanical properties such as TRS and erosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional metal matrix bit bodies are made with WC particles of 60 mesh to 325 mesh size, then the bit body can be manufactured with standard processes, but the Transverse rupture strength remains less than 165 ksi and erosion resistance is moderate to poor
Solution Approach 1:
The patent changes the particle size parameter by introducing coarse WC particles (60-200 mesh) in addition to fine particles (325-600 mesh), altering the size distribution parameter to achieve both high strength and erosion resistance simultaneously
Solution Approach 2:
The patent creates a composite metal matrix structure combining WC particles of multiple size ranges with a copper alloy binder, where the multi-size particle composite provides both the strength from coarse particles and erosion resistance from fine particles
2Strength
If the bit body is made with conventional metal matrix composition, then manufacturing is straightforward, but the Charpy Impact Toughness is limited to about 2.8 to 3.2 ft-lbs
Solution Approach 1:
The patent modifies the particle size distribution parameters and binder composition to achieve superior impact toughness (about 7.0 ft-lbs) while maintaining compatibility with conventional infiltration casting manufacturing processes
3Reliability
If drill bits are made with conventional material properties, then initial manufacturing cost is lower, but frequent bit changes are required increasing drilling costs
Solution Approach 1:
The multi-size WC particle composite with copper alloy binder creates a bit body with enhanced durability and erosion resistance, extending drill bit life and reducing the frequency of bit changes, thereby improving overall drilling productivity
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
The enhanced bit body composition achieves TRS greater than 190 ksi and Charpy Impact Toughness of about 7.0 ft-lbs, improving durability and reducing wear, thereby extending drill bit life and reducing drilling costs.
Implementation Method 1
The mold is heated in a furnace to allow the copper alloy to flow and migrate into the interstitial spaces between the mixed powder particles
Implementation Method 2
The mold is heated in a furnace to allow the copper alloy to flow and migrate into the interstitial spaces between the mixed powder particles
Implementation Method 3
The mixture in the mold is then allowed to cool and solidify into the bit body
Data Source
AI summary
A method for manufacturing a fixed cutter drill bit for drilling an earthen formation, the drill bit including a bit body, the method including (a) preparing a powdered metal matrix mixture including 5.0 wt % to 20.0 wt % of a plurality of large size particles having mesh sizes ranging from 80 mesh to 200 mesh. The plurality of large size particles consist essentially of a plurality of crushed cast tungsten carbide (WC) particles, a plurality of macrocrystalline WC particles, a plurality of spherical cast WC particles, a plurality of tungsten (W) particles, or a combination thereof. The powdered metal matrix mixture also includes at least 50.0 wt % of a plurality of medium size particles having mesh sizes ranging from 200 mesh to 325 mesh. The plurality of medium size particles consist essentially of a plurality of spherical cast WC particles. The powdered metal matrix mixture further includes a plurality of small size particles having mesh sizes ranging from 325 mesh to 600 mesh. The plurality of small size particles consist essentially of (i) a plurality of small size metal or metal alloy particles, and (ii) a plurality of small size macrocrystalline WC particles, a plurality of small size carburized WC particles, a plurality of small size spherical cast WC particles, a plurality of small size W particles, or a combination thereof. The powdered metal matrix mixture still further includes 5.0 wt % to 20.0 wt % of the plurality of small size macrocrystalline WC particles, the plurality of small size carburized WC particles, the plurality of small size spherical cast WC particles, or the combination thereof. The powdered metal matrix mixture also includes 0.0 wt % to 10.0 wt % of the plurality of small size W particles and 0.0 wt % to 7.0 wt % of the plurality of small size metal or metal alloy particles. In addition, the method includes (b) placing the powdered metal matrix mixture in a mold after (a). Further, the method includes (c) positioning an infiltration alloy on top of the powdered metal matrix mixture in the mold after (b). Still further, the method includes (d) heating the mold, the powdered metal matrix mixture in the mold, and the infiltration alloy after (c) to melt the metal or metal alloy particles and melt the infiltration alloy. Moreover, the method includes (e) infiltrating the powdered metal matrix mixture with the melted metal or metal alloy and the melted infiltration alloy during (d). The method also includes (f) cooling the mold, the melted metal or metal alloy, and the melted infiltration alloy to solidify the melted metal or metal alloy and solidify the melted infiltration alloy after (e) to form the bit body.