Mixed Gouging Cutter Drill Bit for Torque-Stable Drilling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Drill bits used for shallow oil and gas wells in coarse grained formations with changing bedrock depth face issues such as bit balling, nozzle plugging, poor hole cleaning, and excessive torque fluctuations, leading to reduced drilling rates and directional control problems due to aggressive combined shear and gouging cutter bits.
Innovation Solution
A drill bit design featuring a combination of rotatably and non-rotatably mounted gouging cutters with specific profiles and materials like tungsten carbide and polycrystalline diamond, optimized for reduced torque and improved drilling efficiency in such formations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If combined shear and gouging cutter bits are used, then drilling capability in coarse grained formations is improved, but torque fluctuations become excessive
Solution Approach 1:
The cutter population is segmented into two distinct types: rotatable cutters and fixed cutters. This segmentation allows each type to perform different functions - rotatable cutters provide rolling action for smoother torque, while fixed cutters provide aggressive material removal, resolving the contradiction between drilling capability and torque stability.
Solution Approach 2:
The cutter mounting system is made dynamic by allowing certain cutters to rotate freely on their mounts while others remain fixed. This dynamic configuration enables the bit to adapt to varying formation conditions, providing both the aggressiveness needed for hard formations and the torque smoothness required for operational control.
2Productivity
If aggressive combined shear and gouging cutter bits are used, then drilling rate is improved, but directional control deteriorates
Solution Approach 1:
By segmenting the cutter population into rotatable and fixed types with different profiles, the bit achieves a balance between aggressive material removal (for drilling rate) and controlled cutting action (for directional control). The rotatable cutters provide stability while fixed cutters maintain aggressiveness.
Solution Approach 2:
Different cutter profiles are assigned to different locations and types within the cutter population. The rotatable cutters have profiles optimized for rolling and stability, while fixed cutters have profiles optimized for aggressive material removal, allowing the bit to maintain directional control while achieving high drilling rates.
3Device complexity
If low drilling flow rates are used, then equipment requirements are reduced, but bit balling and nozzle plugging occur
Solution Approach 1:
The cutter design and arrangement are optimized to pre-condition the formation and control cuttings generation in a way that prevents balling and plugging before they occur. The combination of rotatable and fixed cutters creates a cutting pattern that promotes efficient cuttings evacuation even at lower flow rates.
4Productivity
If combined shear and gouging cutter bits are used, then drilling capability is improved, but wear and abrasion increase
Solution Approach 1:
The dynamic mounting system allows cutters to rotate, which distributes wear more evenly across the cutter surfaces and extends bit life. The ability of rotatable cutters to self-adjust their orientation reduces concentrated wear and abrasion while maintaining drilling capability.
Data Source
AI summary
A drill bit includes a bit body; a plurality of gouging cutters rotatably mounted to the bit body so as to define a first profile; and a plurality of gouging cutters non-rotatably mounted to the bit body so as to define a second profile. The first profile is longitudinally ahead of the second profile in a direction of drilling of the drill bit by a selected distance.